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Disparate Sexual Variation among Gyrinophilus, pseudotriton and Stereochilus (Amphibia: Plethodontidae) Author(s): David M. Sever Source: Herpetologica, Vol. 42, No. 3 (Sep., 1986), pp. 301-323Published by: Herpetologists' LeagueStable URL: http://www.jstor.org/stable/3892310Accessed: 30-06-2015 16:23 UTC

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September 1986] HERPETOLOGICA 301

WILEY, E. 0. 1981. Phylogenetics: The Theory and Practice of Phylogenetic Systematics. John Wiley and Sons, New York.

WORKMAN, P. L., AND J. D. NISWANDER. 1970. Population studies on southwestern Indian tribes. II. Local genetic differentiation in the Papago. Am. J. Human Genet. 22:24-49.

WRIGHT, S. 1965. The interpretation of population

structure by F-statistics with special regard to sys- tems of mating. Evolution 19:395-420.

1978. Evolution and the Genetics of Pop- ulations, Vol. 4. Variability within and among Populations. University of Chicago Press, Chicago.

Accepted: 16 October 1985 Associate Editor: Stephen Tilley

Herpetologica, 42(3), 1986, 301-323 K 1986 by The Herpetologists' League, Inc.

DISPARATE SEXUAL VARIATION AMONG GYRINOPHILUS, PSEUDOTRITON AND STEREOCHILUS

(AMPHIBIA: PLETHODONTIDAE)

DAVID M. SEVER

Department of Biology, Saint Mary's College, Notre Dame, IN 46556, USA

ABSTRACT: The only sexually dimorphic glands in these species are those associated with the cloaca. Male G. porphyriticus and P. ruber are similar to each other in cloacal anatomy, but male P. montanus and S. marginatus differ greatly from those species and from each other in cloacal anatomy. Among females, G. porphyriticus and S. marginatus share some features of cloacal anatomy, including an elongate projection (the cloacal papilla) associated with an extensive recess in the dorsal cloacal chamber. The female cloacal anatomy of these two species differs significantly from that of female P. montanus and P. ruber, which are identical in cloacal anatomy. The only G. palleucus with developed cloacal glands is a naturally metamorphosed male whose cloacal anatomy resembles that of G. porphyriticus and P. ruber. The ancestral and derived states for cloacal structures cannot be determined from available data. Thus, similarities in cloacal anatomy cannot be used at this time to elucidate phylogenetic relationships among these species. The cloacal papilla and recess of female G. porphyriticus and P. ruber may aid in release of sperm from the spermatophore.

Key words: Gyrinophilus; Pseudotriton; Stereochilus; Anatomy; Cloaca; Glands

GYRINOPHILUS (three species), Pseu- dotriton (two species), and Stereochilus (one species) occur in eastern North America and form the most primitive generic grouping in the family Plethodon- tidae (Wake, 1966). Grobman (1959) placed Gyrinophilus in the synonomy of Pseudotriton, but this was disputed by Martof and Rose (1962) and Wake (1966). Wake (1966) stated, however, that Pseu- dotriton and Gyrinophilus resemble each other more closely than either resembles Stereochilus.

Two earlier reports exist on secondary sexual characters in these genera. Dieck- mann (1927) described the cloacal anatomy of female G. porphyriticus. I noted

that males of G. porphyriticus, P. ruber, and P. montanus lack mental hedonic glands (Sever, 1976). Subsequent exami- nation of G. palleucus and S. marginatus has revealed that males of these species also lack mental hedonic glands (Sever, personal observation).

Besides the scarcity of previous studies, there were three additional reasons for initiating this research. (1) Because of the presumed primitive nature of these species, knowledge of their cloacal structure could help elucidate phylogenetic trends in such characters. There are some recent papers dealing with the cloacal anatomy of more advanced plethodontids and of members of groups (Ambystomati-



302 HERPETOLOGICA [Vol. 42, No. 3

TABLE 1.-Data on specimens used in this study. AB = alcian blue at pH 2.5, AL = Alabama, F-sec = frontal section, GD = gross dissection, HE = hematoxylin/eosin, KY = Kentucky, LA = Louisiana, MB = mercuric bromphenol blue, MI = Millon reaction, MTS = Mallory's triple stain, NC = North Carolina, OH = Ohio, PAS = periodic acid/Schiff's reagent, SC = South Carolina, T-sec = transverse section, TN = Tennessee,

S-sec = sagittal section. SAVL and SPVL are in millimeters.

Treatment

Species, sex and locality Collected SAVL/SPVL Type Stain

G. palleucus males Grundy Co., TN 25/VI/83 82/86 T-sec HE Franklin Co., TN 26/VI/83 73/77 T-sec HE/AB Roane Co., TN 27/VI/83 113/119 T-sec HE

G. palleucus females Grundy Co., TN 25/VI/83 86/92 T-sec HE Franklin Co., TN 26/VI/83 76/80 T-sec HE Roane Co., TN 27/VI/83 73/77 T-sec HE

G. palleucus sex undetermined Franklin Co., TN 11/III/83 86.8/90.9 T-sec HE Franklin Co., TN 11/III/83 62.7/74.1 T-sec HE Roane Co., TN 12/III/83 100.4/106.0 T-sec HE Franklin Co., TN 16/III/83 71.0/66.0 T-sec HE Franklin Co., TN 16/111/83 54.2/56.2 T-sec HE

G. prophyriticus males Licking Co., OH 21/VII/67 90.6/94.8 T-sec HE Jackson Co., NC 24/VII/73 77.8/81.1 T-sec HE Macon Co., NC 4/VIII/73 75.2/78.8 GD Macon Co., NC 23/III/79 78.6/81.6 T-sec MTS Graham Co., NC 17/III/82 78.9/82.5 T-sec MI Macon Co., NC 18/III/82 77.1/80.0 T-sec HE Monroe Co., TN 21/X/82 66.4/69.2 S-sec HE Macon Co., NC 23/X/82 63.8/66.6 F-sec HE Macon Co., NC 23/X/82 67.3/69.7 T-sec PAS/MB

G. prophyriticus females Sevier Co., TN 24/III/71 70.5/74.9 T-sec HE Macon Co., NC 9/VIII/73 70.5/74.3 S-sec HE Monroe Co., TN 21/III/79 75.1/80.8 T-sec MTS Monroe Co., TN 20/X/82 81.8/85.2 T-sec PAS/AB/MB Monroe Co., TN 1/IV/80 82.3/87.2 GD

P. montanus males Oconee Co., SC 7/VIII/73 T-sec MTS Oconee Co., SC 7/VIII/73 61.5/64.9 T-sec HE Jackson Co., KY 19/IV/75 70.7/75.2 F-sec HE Jackson Co., KY 12/IV/80 62.8/67.5 S-sec HE/PAS Hoak Co., SC 25/X/82 54.0/56.9 T-sec AB/MB/PAS

P. montanus females Vinton Co., OH 14/VIII/70 76.6/81.1 T-sec HE Oconee Co., SC 7/VIII/73 65.1/69.8 F-sec HE Oconee Co., SC 7/VIII/73 75.7/79.0 S-sec HE Oconee Co., SC 7/VIII/73 T-sec MTS Oconee Co., SC 7/VIII/73 77.4/81.3 T-sec HE Oconee Co., SC 7/VIII/73 78.2/81.8 GD Jackson Co., KY 13/VII/78 63.8/68.1 T-sec HE/PAS Hoak Co., SC 25/X/82 64.0/68.3 T-sec AB/PAS/MB

P. ruber males Tangipahoa Par., LA 18/III/73 83.0/87.1 T-sec HE Macon Co., NC 27/III/75 77.5/84.0 GD Graham Co., NC 14/VII/75 T-sec MTS Graham Co., NC 25/X/77 F-sec MTS Monroe Co., TN 21/III/79 80.0/84.6 T-sec HE




TABLE 1.-Continued.

Treatment

Species, sex and locality Collected SAVL/SPVL Type Stain

Monroe Co., TN 14/III/82 77.9/83.5 T-sec AB/MI Monroe Co., TN 20/X/82 60.5/64.2 S-sec HE Monroe Co., TN 20/X/82 61.6/64.8 T-sec MB/PAS Clay Co., AL 26/X/83 76.0/80.2 T-sec HE/AB

P. ruber females Licking Co., OH 15/VII/64 61.8/65.2 T-sec HE Tangipahoa Par., LA 18/III/73 83.6/88.7 T-sec HE Macon Co., NC 1/VIII/73 65.5/68.2 S-sec HE Graham Co., NC 18/VII/75 T-sec MTS Graham Co., NC 25/X/77 T-sec MTS Graham Co., NC 28/X/77 T-sec MTS Monroe Co., TN 21/III/79 GD Monroe Co., TN 21/X/82 70.9/74.5 F-sec HE Monroe Co., TN 21/III/79 82.5/88.8 T-sec AB/MB/PAS Monroe Co., TN 24/X/83 71.2/75.9 T-sec AB/HE

S. marginatus males Jones Co., NC 25/V/68 40.6/42.2 T-sec HE Jones Co., NC 1/XI/69 41.7/43.4 T-sec HE Jones Co., NC 1/XI/69 48.9/51.2 T-sec MTS Jones Co., NC 1/XI/69 44.3/46.3 T-sec AB/MI Jones Co., NC 1/XI/69 47.4/50.0 GD

S. marginatus females Jones Co., NC 25/V/68 41.2/43.2 GD Jones Co., NC 25/V/68 45.8/47.7 T-sec HE Jones Co., NC 25/V/68 45.7/47.8 S-sec HE Jones Co., NC 1/XI/69 43.2/45.5 T-sec MTS Jones Co., NC 1/XI/69 47.2/49.9 T-sec HE

dae and Salamandridae) that resemble probable plethodontid ancestors (Sever, 1978a,b, 1980, 1981, 1983, 1985). (2) One species, G. palleucus, is paedomorphic (Brandon, 1971; Dent and Kirby-Smith, 1963), although metamorphosed individuals are known (Brandon et al., 1986; Simmons, 1976; Yeatman and Miller, 1985). Some paedomorphic species that have been examined (i.e., Eurycea nana and E. neotenes) have shown few differences in cloacal anatomy from that of related metamorphosing species, and others (i.e., E. tynerensis and Typhlomolge rathbuni) have shown significant differences (Sever, 1980, 1985). (3) Study of cloacal structure may clarify the relationships among members of the three genera. The relationship proposed by Wake (1966) could be supported if Gyrinophilus and Pseudotriton are synapomorphic for cloacal structure and Stereochilus possesses the ancestral state or a different derived state of cloacal anatomy.

The only currently recognized species not examined was G. subterraneus (Be- sharse and Holsinger, 1977). This taxon is known only from the type locality, and only four mature specimens have been reported (Besharse and Holsinger, 1977). Specimens were not available for histolog- ical sectioning.

MATERIALS AND METHODS

Cloacae were examined by gross dissection and by light microscopy after histo- logical preparation by the standard paraffin method. All specimens were initially preserved in 10% formalin that was usually buffered to neutrality. Snout-vent length was measured to the nearest 0.1 mm (1.0 mm in some G. palleucus) from the tip of the snout to the anterior end of the vent (SAVL) and from the snout tip to the posterior end of the vent (SPVL). For the specimens being prepared for light microscopy, the cloacal region was ex- cised, dehydrated in ethanol and cleared




K CP

PV

v~~~

DP

B

DPP

PV

C

FIG. 1.-Diagrams of the cloacal regions of males showing relationships of cloacal gland clusters. (A) G. porphyriticus and P. ruber. (B) P. montanus. (C) S. marginatus. AV = anterior ventral gland; CP = caudal pelvic gland; DP = dorsal pelvic gland; K =

Kingsbury's gland; PV = posterior ventral gland; V = vent gland.

in Histosol (National Diagnostics, Inc.) before paraffin infiltration. Paraffin sections were cut at 10 gm using a rotary micro- tome, and the sections were affixed to al- buminized slides.

Data on the specimens and treatments are summarized in Table 1. Stains and reactions used included hematoxylin-eosin for general cytology, Mallory's triple stain for connective tissue, periodic acid/Schiff's reagent (PAS) for general carbohydrates, alcian blue at pH 2.5 for acid mucopoly- saccharides, the Millon reaction for the amino acid tyrosine, and mercuric bromphenol blue for general proteins. All his- tological procedures followed Humason (1979).

Measurements of gland diameters (n= 11) were performed to the nearest 0.01

mm using an ocular micrometer at 100 x. I used t-tests to determine the significance of differences between means of gland diameters. A probability of a = 0.05 was established a priori as the level for deter- mining whether means were significantly different.

In most gland clusters, due to the extensive curving and the great number of tubules, I did not find it possible to reli- ably trace individual tubules through suf- ficient serial sections to allow measurements of tubule length or exact counts of total tubule number. A measure of approximate tubule number (-n), however, was obtained by counting the number of tubules in a transverse section in which the tubules were straight and the gland mass was dense.

Cloacal tube length (CTL) was estimat- ed by counting the number of 10 ,tm transverse sections between the anterior end of the cloacal tube (as determined by junction of urogenital ducts with the cavity) and anterior end of the cloacal chamber (as determined by the anterior end of the vent). Total cloacal length (TCL) was calculated by adding to the cloacal tube length the number of sections comprising the cloacal chamber. These lengths were approximate because any deviation in the transverse plane of the section made structures appear more anterior or posterior. Also, sections were sometimes miss- ing, although an attempt was made to save every section during sectioning and mounting of samples.

The G. palleucus are in the herpetolog- ical collection of the United States Nation- al Museum, and the remaining specimens are in the Carnegie Museum.

RESULTS

Male Cloacal Anatomy Gyrinophilus porphyriticus and Pseu-

dotriton ruber.-The cloaca and its glands in male G. porphyriticus and P. ruber are similar to each other and to those of Eu- rycea (Sever, 1980, 1981) in conformation, arrangement, cytology and histochemistry. The cloacal glands are all




FIG. 2.- Transverse sections through the cloaca from (A)ante tf

riticus, 8a

V~

FIG. 2.-teraonse-hrse setonstrog the cloacal fromer (A) anterior tow(Ftposerio of thlaal mhalberG. ()Postrphy-

end of the cloacal chamber. Labels same as for Fig. 1.

simple, tubular exocrine glands, but different clusters vary markedly in size and number of tubules and in the nature of the secretory product.

The glands are most hypertrophied in G. porphyriticus collected in March and October and most reduced in those collected in July and August. In P. ruber, the specimens with most hypertrophied glands were collected in July, and those with most reduced glands were collected in March. Three of the October collected specimens of P. ruber have hypertrophied or fairly

hypertrophied gland clusters while the others have glands that are reduced in size.

Pelvic glands secrete into the dorsal roof of the cloaca and can be divided into two clusters based upon position of tubules and staining characteristics (Figs. 1A, 2A-D). One cluster of pelvic glands has anteriorly passing tubules that secrete onto a ciliated evagination of the posterior roof of the cloacal tube and anterior cloacal chamber. These glands also secrete onto ciliated papillae dorsolateral to this evagination and onto unciliated papillae in the same re-



TABLE 2.-Data on gland diameters in males. Widest diameters (n = 11) were measured in transverse sections. All measurements are in millimeters. AVG -

anterior ventral gland, CPG = caudal pelvic gland, DPG = dorsal pelvic gland, KG = Kingsbury's gland, and PVG = posterior ventral gland. Standard deviations (SD) are reported x 10-2.

G. palleucus G. porphyriticus P. montanus P. ruber S. marginatus

Month June March March July August October March October October May November November

SAVL/ SPVL 73/77 67.3/69.7 77.1/80.0 90.6/94.8 61.5/64.9 54.0/56.9 80.0/84.6 61.6/64.8 76.0/80.2 40.6/42.2 41.7/43.3 44.3/46.3

Distal DPG Range 0.15-0,20 0.10-0.19 0.15-0.22 0.17-0.28 0.12-0.17 0.13-0.18 0.06-0.13 0.09-0.15 0.12-0.22 0.06-0.08 0.11-0.17 0.12-0.19 xc- 0.175 0.154 0.184 0.202 0.134 0.158 0.099 0.124 0.167 0.070 0.141 0.164 SD 1.44 2.58 2.50 2.93 2.01 1.66 1.81 2.01 2.83 0.45 1.81 2.25

Proximal DPG Range 0.11-0.18 0.09-0.15 0.08-0.19 0.14-0.25 0.09-0.14 0.10-0.18 0.07-0.11 0.08-0.15 0.11-0.21 0.04-0.08 0.13-0.16 0.11-0.17 x 0.153 0.132 0.139 0.189 0.117 0.139 0.086 0.103 0.140 0.064 0.139 0.135 SD 2.69 1.89 3.75 3.45 1.56 2.62 1.43 2.28 3.16 1.21 1.22 2.25

Distal CPG Range 0.08-0.13 0.10-0.14 0.14-0.24 0.11-0.19 0.07-0.12 0.10-0.18 0.08-0.11 0.11-0.17 0.02-0.05 0.08-0.11 0.06-0.10 | x 0.108 0.120 0.171 0.148 0.091 0.128 0.094 0.138 0.036 0.093 0.080 SD 1.54 1.34 3.70 2.52 1.76 2.23 1.13 2.36 0.81 1.01 1.09

C: Proximal CPG Range 0.09-0.13 0.10-0.17 0.10-0.21 0.07-0.23 0.08-0.13 0.09-0.15 0.05-0.12 0.07-0.13 0.10-0.18 0.03-0.09 0.08-0.13 0.05-0.11 > x 0.109 0.134 0.158 0.142 0.104 0.108 0.085 0.095 0.134 0.057 0.102 0.083 SD 1.38 2.25 3.97 4.56 1.75 1.99 2.02 1.81 2.73 1.85 1.60 1.79

Distal AVG Range 0.08-0.13 0.09-0.14 0.09-0.14 0.11-0.16 0.08-0.15 0.10-0.17 0.06-0.10 0.07-0.15 0.12-0.15 0.03-0.08 0.06-0.11 0.06-0.09 xf 0.101 0.108 0.112 0.138 0.113 0.137 0.083 0.104 0.129 0.044 0.081 0.076 SD 1.87 1.33 1.47 1.83 2.41 2.90 1.49 2.25 1.22 1.43 1.44 1.03

Proximal AVG Range 0.08-0.12 0.10-0.16 0.11-0.18 0.13-0.19 0.09-0.15 0.10-0.25 0.06-0.10 0.05-0.17 0.11-0.15 0.03-0.05 0.07-0.10 0.06-0.11 x 0.097 0.124 0.139 0.157 0.123 0.158 0.087 0.114 0.134 0.037 0.087 0.084 SD 1.27 1.86 2.26 2.00 1.68 4.24 1.42 4.16 1.69 0.65 0.90 1.50

Caudal AVG Range 0.10-0.19 0.12-0.17 0.14-0.20 0.10-0.22 0.09-0.15 0.13-0.23 0.07-0.14 0.10-0.18 0.03-0.06 0.11-0.18 0.10-0.19 x 0.136 0.149 0.170 0.174 0.109 0.175 0.101 0.134 0.044 0.139 0.140 SD 3.04 1.51 2.45 4.48 2.34 3.53 2.07 2.73 0.93 2.34 2.57

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gion in the anterior one-third of the cloacal chamber. These glands are elongate. Cranial ends of some extend retroperito- neally dorsal to the posterior end of the intestine.

Neither G. porphyriticus nor P. ruber has the cranially passing pelvic glands divided into two readily distinguishable regions, the dorsal and the dorsolateral pelvic clusters, as in Eurycea, Desmognathus and several Plethodon (Sever, 1981, 1983). The lack of such distinct divisions to the cranially passing pelvic glands was also noted in Phaeognathus hubrichti (Sever, 1983) and Typhlomolge rathbuni (Sever, 1985). For the latter, the name dorsal pelvic gland (DPG) was used for all the cranially passing pelvic gland tubules, and that name will be used herein.

Posterior to the depression of the dorsal roof of the cloaca, the DPG's are replaced by caudal pelvic glands (CPG's), whose distal ends pass posteriorly. CPG's secrete onto unciliated papillae of the mucosa forming the roof of the anterior cloacal chamber.

The numbers of tubules involved in DPG and CPG masses are similar in most specimens. For both glands, counts of - 100-175 tubules occur by counting

transverse sections near the distal ends of the two gland masses.

The distal diameters of the DPG tubules are larger than the proximal diameters in all G. porphyriticus and P. ruber measured (Table 2), and this difference is significant in all but the July collected G. porphyriticus and the March specimen of P. ruber. No significant differences occur in any of the specimens between mean diameters of distal and proximal portions of CPG's.

The secretion of the pelvic glands con- sists of a mixture of globular and granular material. Distally in the DPG, the globular material often fills the entire lumen in active glands, and the globules form a colloid similar in appearance to that seen in the thyroid gland (Copenhaver et al., 1978). Within the colloid, smaller globules are often present. Surrounding this colloid is a fringe of granular material, and granular material is also present in the apical




cytoplasm of active glands. Proximally, the colloid often appears broken into three or four large globules, that still may contain smaller globules within, and the granular material is more abundant. Where the secretion has been expressed from a gland into the cloacal cavity, the globules seem to form most of the secretion, and the granular material appears to remain largely in the proximal end of the gland.

The cytoplasm of the DPG's is usually basophilic, and the granular secretion stains positively with PAS and alcian blue but negatively with mercuric bromphenol blue. The colloid and globules are eosinophilic or lightly basophilic, and they react negatively with PAS, alcian blue and mercuric bromphenol blue, except that a few smaller globules in the colloid react positively. The colloid in the DPG's of G. porphyriticus give a slight positive reaction when treated with the Millon reaction, but the reaction in P. ruber is negative. With Mallory's, the colloid of the DPG varies from light orange to blue, and portions of the granular material may appear gray while some smaller globules are red. The cytoplasm of the DPG varies from gray to red in Mallory's.

In the CPG, distally the lumen appears filled with a colloid that contains smaller globules and patches of granular material. Thus, the colloid does not appear uni- formly dense as in the DPG. The luminal contents generally appear eosinophilic although some of the materials are basophilic. The luminal contents have an overall strongly PAS positive appearance, although only the granular component and some of the smaller globules are alcian blue positive. Proximally, as in the DPG, the colloid is broken into several large globules which fill most of the lumen in the CPG, except where some secretion has been expressed into the cloacal chamber. In such glands, much more of the granular than the globular material seems to remain in the proximal ends. Distally, the lumen gives an overall positive reaction with mercuric bromphenol blue, but this is apparently due primarily to the globular material, for the reaction is weak in the proximal ends of glands that just re- tain granular material.

The cytoplasm of the CPG is lightly basophilic, and apical portions of active glands react positively with PAS and alcian blue. With Mallory's triple stain, the luminal contents are dark orange overall with small red and red-orange globules as well as gray and blue staining components mixed together. The cytoplasm of CPG's varies from gray to violet in Mallory's.

The remaining cloacal glands have only granular secretory products, lacking the globular component found in the pelvic glands. Anterior ventral glands (AVG's) secrete in the walls forming the borders of the cloacal orifice except for the posterior one-third of the cloacal chamber (Fig. 1A). Cranially, AVG's secrete onto the ciliated epithelium of the medial tips of deep, narrow folds (cloacal rugae) lining the anterior one-half of the cloacal chamber (Fig. 2A-C). Distal ends of this cranial group of AVG's pass anteriorly and laterally. These tubules are quite elongate, and distal ends of some cranially passing AVG's extend anteriorly further than any tubules of the DPG. Other AVG's secrete upon unciliated papillae which replace the rugae in the posterior half of the cloacal chamber (Fig. 2D-F). The tubules of these AVG's pass caudally. The caudal AVG's are also elongate, and their distal ends may extend beyond the posterior end of the vent.

The cranial group of AVG's forms the largest mass of cloacal gland tubules, and =2OO-300 glands occur in transverse sections at the anterior end of the cloacal tube. In contrast, counts of =60-100 tubules occur for the caudal group of AVG's at the posterior end of the cloacal chamber. The mean diameters of the proximal ends of the cranial group of AVG are greater than that of the distal ends in G. porphyriticus and P. ruber (Table 2), but this difference is significant only for the G. porphyriticus. Also, mean diameters of the caudal AVG's are significantly greater than diameters of both the proximal or distal cranial AVG's in all specimens of G. porphyriticus except the July collected specimen. In P. ruber, there are no significant differences in mean diameters between the caudal AVG's and distal or proximal cranial AVG's.




Around the posterior end of the cloacal orifice, the caudal AVG's are replaced by the posterior ventral glands (PVG's) whose distal ends also pass caudally. The PVG's seem relatively shorter than caudal AVG's, as the distal ends of the latter usually extend further posteriorly (Fig. IA). PVG's are also relatively less numerous than caudal AVG's, with counts of -40-60 tubules occurring in transverse sections where PVG's are most dense. PVG's replaced CPG's around the dorsal end of the posterior cloacal chamber (Fig. 2E). PVG's secrete upon unciliated papillae, and PVG's no longer secrete into the cloaca after the posterior end of the vent shortens to a degree that epidermis replaces the cloacal mucosa. The replacement of CPG's with PVG's at the dorsal apex of the posterior cloacal chamber is not as extensive in P. ruber as in G. porphyriticus. In P. ruber, this process happens almost simul- taneously with the encroachment of epidermis, thus allowing PVG's to secrete into the dorsal apex of the cloacal chamber in very few sections. In G. porphyriticus, in contrast, PVG's occupy the dorsal end of the cloacal chamber for approximately the entire posterior one-fourth of the cavity before the most caudad, epidermally lined angle of the slit.

Kingsbury's glands (KG's) are the most cranial glands to secrete into the cloaca, first appearing along the lateral edges of the anterior end of the cloacal tube (Fig. 2A). They are quite numerous in this region, with -40-60 tubules appearing in some transverse sections. In the area of the depression of the cloacal roof, however, KG's become sandwiched into several lateral layers between tubules of the DPG and AVG (Figs. IA, 2B-C). The occurrence of the most caudal tubules of KG's and DPG's coincides with the appearance of the most cranial appearance of PVG's. The distal ends of those KG's surrounding the anterior cloacal tube generally pass cranially and dorsally, while tubules of more caudad KG's pass laterally and posteriorly.

The granular clocal glands have basophilic cytoplasm and luminal contents that stain strongly with PAS and alcian blue, although some tubules of the PVG show a

lighter reaction to alcian blue than that of the other glands. None of these glands give a positive response with either the Million reaction or mercuric bromphenol blue. In Mallory's, the cytoplasm and secretion vary from light gray to blue.

The vent glands (VG's) are a group of numerous (e60-80) small glands secreting onto the epidermal lining of the posterior end of the vent (Figs. IA, 2F). In length, vent glands rarely exceed 3 x their diameter, and some appear almost acinar. VG's are characterized by a lightly basophilic, fluctated epithelium whose luminal border contains granules. These granules are strongly PAS positive but alcian blue negative, although sometimes a very light reaction with alcian blue occurs in some glands. There is no response to the Millon reaction in the specimens tested, although the VG's of a G. porphyriticus give an intensely positive reaction with mercuric bromphenol blue. In Mallory's, the cytoplasm is a mixture of orange and blue materials in G. porphyriticus while the glands are primarily purple (anteriorly) and red (posteriorly) in P. ruber with some orange and yellow elements also present. Lumi- nal secretion is generally scarce in VG's, but when it occurs, it stains in the same manner as the cytoplasm.

Besides the variation noted in the PVG, differences in cloacal anatomy between male G. porphyriticus and P. ruber are few. The cloacal tube, with one exception, is relatively shorter in the P. ruber examined than in G. porphyriticus. For three G. porphyriticus, the CTL/TCL quotients are 0.226 (69.7 mm SPVL), 0.298 (81.1 mm SPVL), and 0.326 (80.0 mm SPVL). In two P. ruber (64.8 mm and 87.1 mm SPVL), the urogenital ducts open in the same sections that mark the anterior end of the cloacal chamber, so a cloacal tube is absent. In two other P. ruber, however, the quotients are 0.115 (84.6 mm SPVL) and 0.275 (80.2 mm SPVL).

Subjectively, KG's are better developed and occur further posteriorly in G. porphyriticus than in P. ruber, although these differences are slight. Indeed, both species possess much larger and more extensive clusters of KG's than ever reported for another plethodontid. Around the anterior




cloacal tube, the appearance of Kings- bury's glands is reminiscent of Ambysto- ma tigrinum, in which KG's are as numerous as DPG's (Sever, 1981). In several specimens of both species stained with hematoxylin/eosin, the KG's appear to grade into the larger PVG's and into the similar- sized VG's. Histochemical tests, however, help distinguish these glands because the VG's typically do not react with alcian blue while the others react with the stain.

Pseudotriton montanus.-Male P. montanus differ from those of P. ruber and G. porphyriticus primarily in anatomy of the PVG and VG (Figs. 1B, 3A). A PVG readily distinguishable from the AVG on the basis of staining characteristics, size and direction of tubules does not exist. Thus, PVG's do not come to replace CPG's and line the mucosal portion of the posterior end of the vent as in the other species. Instead, the VG's are numerous, relatively elongate, and replace the CPG's. As in the other species, the identity of the VG's in P. montanus can be established by their granular secretion, negative reaction with alcian blue, slightly positive reaction to mercuric bromphenol blue, and intensely positive reaction to PAS.

Otherwise, anatomy and histochemistry of the cloaca and its glands in P. montanus are similar to those of G. porphyriticus and P. ruber. Glands of the specimens collected in July and October are hypertrophied, while those individuals collected in April and March have reduced glands. In the August collected specimen (Table 2), the mean diameter for the distal DPG tubules is significantly different from that for the proximal DPG, but there are no such differences between means for portions of the CPG and AVG. In the October collected specimen, there are significant differences between means for distal and proximal portions of the CPG as well as between distal portions of the cranial AVG and the caudal group of AVG tubules.

The CTL/TCL quotients are 0.138 and 0.141 for two specimens 64.9 mm and 56.9 mm SPVL respectively. Thus, P. montanus, like P. ruber, has a relatively short cloacal tube. In the October collected

specimen, the following approximate gland numbers occur in transverse sections where the appropriate mass was den- sest: AVG e 300, CPG = 80, DPG 100, KG = 80, and VG 60.

Gyrinophilus palleucus.-The only mature specimen examined is a naturally metamorphosed individual (77 mm SPVL) described by Brandon et al. (1986). The cloacal glands of this specimen, however, are not fully hypertrophied. As reported by Brandon et al. (1986), only early sper- matogenesis has occurred in the testis (primary and secondary spermatocytes), and the specimen is in emaciated condition. Either or both of these factors may influence the developmental state of the cloacal glands. Still, the anatomy and histochemistry of the cloaca and its glands in this specimen resemble the conditions found in G. porphyriticus and P. ruber. The cloacal tube, however, is relatively longer in the G. palleucus than in P. ruber and most G. porphyriticus. The CTL/TCL quotient is 0.326. Perhaps due to the relatively long cloacal tube, many of the gland clusters seem to be "shifted" anteriorly. All of the DPG's and KG's secrete into the cloacal tube, and even the most anterior CPG's are found in the cloacal tube (Fig. 3B).

The PVG cluster of G. palleucus resembles that of P. ruber more than that of G. porphyriticus (Fig. 3C). Also, the epidermally lined, posterior end of the vent, where only VG's secrete, is relatively longer in G. palleucus than in the other species examined. VG's line the entire vent slit at its posterior end, and some continue medially just posterior to the vent. VG's therefore seem more numerous in G. palleucus than in the other species examined. Otherwise, numbers of cloacal glands appear comparable to counts for G. porphyriticus and P. ruber.

The mean distal DPG diameter is significantly larger than that for the proximal tubules, and the mean for the caudal AVG diameter is significantly greater than those of either the distal or proximal tubules of the cranial AVG (Table 2). No significant differences exist between means for distal and proximal tubules of the CPG




5,~ ~ ~~~~~~ W

A~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

IN.

L -~~~~~~~~~~~ ~F -:w

FIG. 3.-Transverse sections through cloacal and skin glands in males. Scale in lower right corner of E= 150,um. Sections stained in hematoxylin-eosin except for A which was stained with mercuric bromphenol blue. (A) Posterior end of the cloacal chamber of a P. montanus., 56.9 mm SPVL. (B) Posterior end of the cloacal tube of a metamorphosed G. palleucus, 77 mm SPVL. (C) Same specimen as B, section through posterior end of the cloacal chamber. (D) Anterior cloacal chamber of a paedomorphic G. palleucus, 119 mm SPVL. (E) Same specimen as D, section through posterior end of the cloacal chamber. (F) Skin lateral to the posterior end of the vent in a P. montanus, 64.9 mm SPVL. (G) Skin lateral to the posterior end of the vent in a G. porphyriticus, 81.1 mm SPVL. Labels same as for Fig. 1 plus GL = glands; GR = granular glands; LC = Leydig cells; M = mucous glands.

or the distal and proximal portions of the cranial AVG.

Two other paedomorphic individuals are readily identifiable as males by ex- amination of their gonads. Sections through their testes reveal primary spermatocytes posteriorly and spermatogonia anteriorly. Neither of these two larval specimens has cloacal glands except for numerous, short tubules in the anterior half of the cloacal chamber (Fig. 3D). Such

glands appear most cranially at the anterior end of the cloacal chamber where they secrete around the ventral border of the cloacal slit. These "ventral" glands end after the anterior one-fourth of the cloacal chamber, and another group appears around the dorsal apex of the cloacal chamber and continues until the midpoint of the cavity. The dorsal and ventral groups are not continuous with one another. These glands are very rudimen-




QQQQ -

FIG. 4.-Transverse sections through the cloaca from (A) anterior to (B) posterior of a male S. marginatus, 43.3 mm SPVL. Scale in lower right corner = 150 ,m. Sections stained in hematoxylin-eosin. (A) Depression of the cloacal tube roof. (B) Posterior cloacal tube. (C) Posterior one-third of the cloacal chamber. (D) Posterior end of the cloacal chamber. Labels same as for Fig. 1.

tary, possess basophilic cytoplasm, and have no discernible secretory products. Diameters of 11 of the glands in the 86 mm SPVL specimen (Table 1) are 0.03- 0.05 mm (x = 0.042 mm, SD x 10-3 -

7.51), and diameters of 11 glands in the 119 mm SPVL specimen are 0.094-0.06 mm (x = 0.049 mm, DS x 10-3 = 8.31). The epithelium lining the entire cloacal chamber is stratified.

These glands also occur in the three largest individuals (74.1-106.0 mm SPVL) of G. palleucus of undetermined sex (Ta- ble 1). The two smaller specimens (56.2- 66.0 mm SPVL) lack glands.

Along the posterior border of the cloacal orifice, Leydig cells extend into the epithelium of the lateral walls of the cloacal chamber (Fig. 3E). At the posterior end of the vent slit, Leydig cells are stratified into 2-3 layers.

The mature male G. palleucus has fully metamorphosed skin. The epidermis has two layers of cuboidal cells superficial to which is a squamous, cornified layer. The dermis has two layers, a superficial loose area of connective tissue where acini of mucous and granular glands occur, and a deep fibrous layer. The skin of the other G. palleucus, in contrast, is typical of larval plethodontids, possessing an epidermis consisting of Leydig cells scattered among two or three layers of epithelial cells, and a single-layered dermis composed of fibrous connective tissue.

Lateral and posterior to the cloacal orifice in P. ruber and P. montanus, granular glands are found scattered among mucous glands (Fig. 3F). In G. porphyriticus and the metamorphosed G. palleucus, the granular glands are not found in this area immediately posterior and lateral to the cloacal orifice. Only mucous glands, which are numerous, occur in these areas around the vent (Fig. 3G), although granular glands are found more laterally and posteriorly in the skin. In the larval G. palleucus, of course, only Leydig cells are found among normal epidermal cells in the skin, but Leydig cells are extremely numerous in all areas of the skin surrounding the vent.

Stereochilus marginatus.-The three males examined that were collected in November have hypertrophied glands while the male collected in May has reduced glands. The cloacal anatomy of S. marginatus is quite distinct from that of the other species examined (Figs. 1C, 4).

S. marginatus has a relatively long cloacal tube. The CTL/TCL quotients in two S. marginatus are 0.294 (42.2 mm SPVL) and 0.425 (43.3 mm SPVL). In S. marginatus, the depression of the roof of the cloaca occurs in the middle of the cloacal tube instead of at the posterior end. The anteriorly passing pelvic glands (i.e., DPG's) can be divided into a dorsal (= 100) and a dorsolateral (=40) cluster, although this division is based solely upon position and not on any histochemical or cytolog- ical differences. At the level at which the dorsal portion of the DPG is secreting into the depression of the roof of the cloacal




tube, AVG's (e2O) are secreting onto the anteriormost tips of the ciliated rugae ventrally, and KG's (-40) are found in two lateral layers between the DPG's and AVG's (Fig. 4A).

Posterior to this depression, CPG's (= 100-150) secrete through unciliated papillae onto the roof of the posterior cloacal tube, and they continue in this position throughout the anterior two-thirds of the cloacal chamber. Posterior to the depression, as the floor of the cloacal tube evaginates ventrally, the dorsolateral group of DPG's secretes onto the ciliated (anteriorly) and unciliated (posteriorly) papillae between the CPG superiorly and the caudal AVG (=80) inferiorly (Fig. 4B). A few KG's are found in this area, but they no longer occur by the anterior end of the cloacal chamber.

The most cephalic PVG's appear in single, lateral layers ventral to the dorsolateral DPG at the anterior end of the cloacal chamber. These most cranial PVG's replace the most caudal KG's in position, secreting on a large, ciliated papilla di- rectly dorsad of the most superior of the cloacal rugae. Thus, at the anterior end of the cloacal chamber, CPG's secrete into the dorsal apex, dorsolateral DPG's secrete onto the dorsolateral walls, caudal AVG's secrete onto the ventrolateral walls, and a layer of PVG's occurs between the DPG and AVG masses.

This situation continues until the posterior one-third of the cloacal chamber where the cloacal rugae terminate in a laterally widened chamber similar to that noted for Notophthalmus viridescens and Ambystoma tigrinum (Sever, 1981). In this area, the caudal AVG's secrete into the widened chamber and PVG's replace the dorsolateral DPG's in the area superior to the widened chamber (Fig. 4C). Tubules of the PVG are shorter than those of CPG's or the caudal AVG, and distal ends of the PVG's pass laterally and dorsally.

As the height of the posterior cloacal chamber gradually shortens, PVG's replace the CPG's secreting around the dorsal apex of the cloacal chamber (Fig. 4D). Compared to other posterior cloacal

glands, PVG's are relatively few in number (=40 tubules in a densely packed transverse section). With shortening of the cloacal chamber, the ventral widened area ends in the posterior one-fourth of the cloacal chamber, and the caudal AVG's cease secreting into the cavity. As the mucosa of the walls of the cloacal chamber is replaced by epidermis in the posterior angle of the vent, the PVG's disappear, to be replaced by VG's (=30). Posteriorly passing tubules of the caudal AVG's occur between the cloacal sheath and tail muscu- lature posterior to the point where tubules of all other cloacal glands have ended but those of vent glands.

The cytoplasm and luminal contents have a distinctly eosinophilic appearance, and these elements stain a dark blue in Mallory's. These reactions are different from those of the other species examined in this report. Also, small globules in the dorsal and dorsolateral portions of the DPG respond positively to the Millon reaction, a condition also noted in G. porphyriticus. All other reactions and cyto- logical details for the cloacal glands of S. marginatus are similar to those reported for the other species.

In both of the November collected specimens (Table 2), the means for diameter of the caudal AVG's are significantly different from those for proximal and distal portions of the cranial AVG's. In the May specimen, the means for distal and proximal portions of the CPG are significantly different as are the means for distal and proximal portions of the DPG in the 46.3 mm SPVL specimen from No- vember (Table 2).

Both granular and mucous glands are numerous in the skin around the cloacal orifice in S. marginatus.

Female Cloacal Anatomy Gyrinophilus porphyriticus.-Ovarian

follicle diameters are 2.2-3.1 mm for the March specimens, 2.0-3.0 mm for the April specimen, 0.4-0.5 mm for the July specimen, and 1.1-1.2 mm for the Octo- ber specimen (Table 1). Spermatozoa occur in the spermathecae of the specimen collected 24 March 1971 and in the indi-




R

A

S R

B

S

FIG. 5. -Midsagittal sections through the cloacal region of females showing conformation of the cloacae and location of the spermathecae. (A) G. porphyriticus. (B) S. marginatus. (C) P. montanus and P. ruber. P = cloacal papilla; R = recess of the cloacal chamber; S = spermatheca.

vidual collected in October. Spermatozoa are absent from the individual collected 21 March 1979 and in one collected in July.

In general, I found the appearance of the cloaca in female G. porphyriticus con- sistent with the description given by Dieckmann (1927). Thus, the following remarks on the species will emphasize details not mentioned by Dieckmann and areas where our observations differ.

The cloacal tube is short or absent (Fig. 5A). In two specimens (74.9 mm and 85.2 mm SPVL), the urogenital ducts pass into the anterior end of the cloacal chamber, so a cloacal tube is absent (Fig. 6A). In another specimen (80.8 mm SPVL), the CTL/TCL quotient is 0.058.

The mucosa of the posterior intestine is simple columnar, and the apical cytoplasm of the mucosal epithelium reacts positively with PAS and alcian blue. The

urinary bladder is the most anterior of the urogenital structures to merge with the intestine, and posterior to this region, the ventral epithelium becomes aglandular and stratified. This condition spreads dorsally as the oviducts and finally the Wolf- fian ducts merge with the gut so that at the anterior end of the cloacal chamber, almost the entire epithelial lining of the cavity is stratified into 2-3 cuboidal layers with a superficial cornified layer (Fig. 6A). This is identical to the appearance of the epidermis with which the lining of the cloacal chamber is continuous.

The only part of the cloacal chamber that is not lined with stratified epithelium is the common tube of the spermatheca (Fig. 6A, B). The common tube most anteriorly appears medial to the proximal ends of the Wolffian ducts, and its cytoplasm is simple columnar similar to that of the posterior gut (Fig. 6A). The apical cytoplasm of the common tube, however, does not react with alcian blue, although it is PAS positive. Cilia are not associated with the epithelium of the common tube or any other part of the posterior intestine or cloaca.

The common tube of the spermatheca is angled posteriorly. From the distal end of the common tube, narrow neck tubules radiate outward (Fig. 6B). Lengths of neck tubules are difficult to measure because they are curved, but they are relatively uniform in length. In three specimens, neck tubule lengths are -0.12-0.30 mm. At the distal ends of the neck tubules are the spermathecal bulbs. Total numbers of bulbs in three specimens are 16 (74.9 mm SPVL), 22 (80.8 mm SPVL) and 26 (85.2) SPVL). Data on the sizes of bulbs are given in Table 3.

As with the common tube, the epithelium of the neck tubules and bulbs is simple columnar. The epithelium of the bulbs, however, has a fluctated appearance (Fig. 6B). The cytoplasm of the bulbs and neck tubules is eosinophilic, PAS positive and stains bluish in Mallory's. It does not react with alcian blue or mercuric bromphenol blue. Each bulb is surrounded by a sheath of myoepithelial cells and concentric layers of smooth muscle. Melanocytes are




1. . .0 I, svAsW A~j . -

w'S~~~~~~~~~~~~~~~~~~~~~~~~~~~.

2 ~~~~~~~~~~~~ f~~~~~~~

IG. 6-rnvrescostla stained in heaoyi-oi ecpo hchwssandiMloystilsanAo.l

UN,~~~~~~~~~~~~~~,

FIG. 6.-Transverse sections through the cloacae of females. Scale in lower right corner =150 Aim. Sections stained in hematoxylin-eosin except for D which was stained in Mallory's triple stain. (A) Dorsal portion of the anterior end of the cloacal chamber of a G. porphyriticus, 74.9 mm SPVL. (B) Same specimen as A, spermatheca. (C) Anterior cloacal chamber of a paedomorphic G. palleucus, 80 mm SPVL. (D) Posterior cloacal tube of a S. marginatus, 45.5 mm SPVL. (E) Anterior end of the cloacal chamber of a S. marginatus, 49.9 mm SPVL. (F) Same specimen as E, anterior third of the cloacal chamber, showing remnants of a spermatophore cap in the recess. CT = common tube; DG = dorsal glands; GL = glands; NT = neck tubules; R = recess; SB = spermathecal bulbs; SC = spermatophore cap; SP = spermatozoa; VG = ventral glands; WD = Wolffian duct.

found in the connective tissue of the spermathecal area.

The spermatheca is at the anterior end of a large, tongue like extension from the dorsal cloacal wall (Figs. 5A, 6B). Dieck- mann (1927) called this the dorsal diver- ticulum while Sever (1978), who noted a similar structure in Plethodon dorsalis, called it the cloacal papilla. This extension if formed by paired recesses that appear ventrolateral to the spermathecal region

and unite middorsally just posterior to the spermatheca. In one specimen, the spermatheca occupies the anterior 500 ,um of the cloacal chamber, the recess occupies the next 500 ,m, and the rest of the cloacal chamber is about 3 mm in length. A similar proportional relationship of these structures occurs in the other specimens.

Another type of cloacal gland occurs that has been called the female "ventral gland" (Dieckmann, 1927a; Kingsbury,




TABLE 3. -Diameters of spermathecal bulbs (SB) and ventral glands (VG) from female salamanders; n = 11 except for SB data for the P. ruber lacking SPVL, for which n = 6. Measurements are in millimeters.

Standard deviations (SD) are reported x 10-2.

SB VG

Species Month SPVL Range SD Range x SD

G. porphyriticus March 80.8 0.12-0.21 0.172 3.09 0.07-0.13 0.104 2.11 March 74.9 0.11-0.18 0.146 2.25 0.07-0.16 0.110 2.86 Oct 85.2 0.10-0.20 0.153 3.16 0.05-0.08 0.069 1.14

P. montanus July 68.1 0.06-012 0.087 1.85 0.05-0.08 0.064 0.82 Aug 81.1 0.08-0.12 0.101 1.30 0.05-0.07 0.056 0.81 Aug 81.3 0.07-0.17 0.118 3.34 0.07-0.12 0.092 1.47 Oct 68.3 0.08-0.12 0.103 1.27 0.09-0.11 0.099 0.70

P. ruber March 88.7 0.06-0.12 0.090 1.55 0.05-0.07 0.058 0.75 March 88.8 0.09-0.15 0.114 1.80 0.04-0.06 0.050 0.77 July 0.10-0.19 0.143 3.33 0.10-0.16 0.130 1.73 July 65.2 0.04-0.08 0.060 1.18 0.04-0.06 0.053 0.79 Oct 75.9 0.10-0.14 0.116 1.57 0.07-0.11 0.082 1.08

S. marginatus May 47.7 0.04-0.09 0.072 1.40 0.01-0.03 0.018 0.60 Nov 45.5 0.08-0.14 0.114 1.69 0.04-0.07 0.057 0.90 Nov 49.9 0.09-0.18 0.143 3.26 0.05-0.07 0.058 0.75

1895; Sever, 1985). As pointed out else- where, these female ventral glands may not be homologous with male ventral glands, although the glands in females do occupy the same general region as some of the anterior ventral glands in males (Sever, 1985). Female ventral glands secrete at the medial tips of dorso-ventrally oriented folds in the anterior end of the cloacal chamber. The glands secrete at the dorsal end of these folds rather than around the cloacal orifice (Fig. 6A). Also, the area in which the glands secrete is lim- ited to those folds ventral to the spermatheca. From these folds, the distal ends of most of the ventral glands pass cranially and dorsally, many extending to the region just anterior to where the urinary bladder joins the posterior intestine.

The distal ends of ventral glands are relatively straight. The proximal ends are more tortuous, and they curve dorsally just before passage into the rugae. The glands are simple, and gland diameter is constant throughout their length. Data on the diameters of ventral glands from some specimens are given in Table 3. Those of the July specimen are especially reduced, perhaps due to seasonal variation. Aproxi- mate total numbers of ventral glands in three specimens were -50 (85.2 mm

SPVL), =56 (74.9 mm SPVL) and =74 (unknown SVL).

The cytoplasm of the ventral glands is granular, eosinophilic, and stains greenish blue in Mallory's. The granules do not react with alcian blue, but they give mod- erate reactions with PAS and mercuric bromphenol blue.

As noted above, the region posterior to the cloacal recess comprises about three- fourths of the total cloacal length (Fig. 5A). This area has deep, dorso-ventrally di- rected folds, but no glands occur in the cloacal lining. The walls of the cloacal chamber posterior to the cloacal papilla simply shorten gradually until even with the epidermis. Some mucous glands occur in the dermis of the slight indentation marking the caudal end of the vent slit.

Finally, Dieckmann (1927) noted an additional group of small, "rudimentary" glands in some of her specimens of G. porphyriticus. These glands, which num- bered 3-4 pairs, opened into the middor- sal slit caudal to the spermatheca. Dieckmann (1927) noted that the occurrence of these glands was variable, and sometimes they were absent. I failed to find such glands in my specimens.

Gyrinophilus palleucus. -All of the specimens identified as females are im-




mature. The ovaries and oviducts are barely recognizable as such. Oviducts are thin and straight, and diameters of ovarian follicles are 0.2-0.5 mm in the Grundy and Roane County specimens, and 0.5-0.7 mm in the Franklin County specimen. The cloacal anatomy of the female G. palleucus does not differ significantly from that noted for larval male specimens. There are no glands in the cloacal tube. Small rudimentary glands occur around the ventral border of the anterior end of the cloacal orifice in all specimens. A group of dorsally located glands exists further posteriorly in the cloacal chamber of the Franklin and Grundy County females (Fig. 6C), but this dorsal group is absent in the Roane County specimen.

Summary statistics for the diameters of 11 dorsal and ventral glands are the same for both the Grundy and Roane County specimens. These glands are 0.03-0.05 mm (x = 0.043 mm, SD x 10-3 = 7.86), and no significant differences occur between the mean for the females and those reported for similar glands in larval male G. palleucus. As with the male larvae, the glands are basophilic with no discernible secretory product. The glandular cytoplasm in the Grundy County specimen shows no reaction with alcian blue. Also as in male larvae, Leydig cells invade the posterior cloacal orifice.

Stereochilus marginatus.-Diameters of ovarian follicles of the specimens collected in May are 0.3-0.4 mm and those of the November specimens are 1.2-1.5 mm. Sperm are present in the bulbs of the No- vember specimens and absent in those of the May specimens. Two specimens, the 49.9 mm SPVL individual collected in November and the 47.7 mm SPVL specimen collected in May, are represented by complete series of transverse sections, and these are the specimens referred to in subsequent statements about cloacal dimen- sions and gland sizes in the November and May specimens.

The cloacal anatomy of female S. marginatus is similar to that of female G. porphyriticus except that the cloacal tube is much longer, and the spermatheca is

found in the posterior one-half of the cloacal tube instead of the anterior portion of the cloacal chamber (Figs. 5B, 6D). In the November specimen, the CTL/TCL quotient is 0.254 and for the May specimen, the CTL/TCL quotient is 0.313. Dorsal and lateral recesses such as found in G. porphyriticus occur in the cloacal chambers of the female S. marginatus, but these recesses are best developed in the November specimens. In the November specimen mentioned above, the recess appears just caudal to the spermatheca at the anterior end of the spermatheca (Fig. 6E). The recess in this specimen continues through the anterior one-fourth of the cloacal chamber (Fig. 6F). In the May specimen noted above, the recess is represented by a dorsal elongation of the roof beyond the anterior one-seventh of the cloacal chamber, and this elongation simply shortens posteriorly.

The cloacal rugae are well developed in the cloacal tube and anterior one-half of the cloacal chamber, but the posterior walls of the cloacal chamber are smooth and without deep folds. As in G. porphyriticus, the epithelium of the floor of the gut tube becomes stratified as it evaginates towards the vent, and the entire cavity is lined with stratified epithelium by the anterior end of the cloacal chamber. The evagination of the floor of the cloacal tube is sharply angled vertically, so the cloacal chamber appears to begin abrupt- ly (Fig. 5B).

Ventral glands secrete on the dorso- medial tips of the cloacal rugae, begin- ning just caudal to the anterior appearance of the spermatheca (Fig. 6D), and ending at the anterior end of the cloacal chamber. The ventral glands appear reduced in the May specimens. Data on diameters of ventral glands in some specimens are given in Table 3.

The cytoplasm of the ventral glands of S. marginatus is basophilic as opposed to eosinophilic in G. porphyriticus, and in Mallory's, the secretory granules are orange or yellow. There are -34 ventral glands in the November specimen and

e42 in the May specimen.




Again, as in G. porphyriticus, no cilia occur anywhere in the cloaca of S. marginatus, and the epithelium of the common tube, neck tubules, and spermathecal bulbs is simple, although that of the bulbs is highly fluctated. Both the November and May specimens had 24 spermathecal neck tubules and bulbs radiating from the common duct. Neck tubules in these specimens are ~0.11-0.25 mm, and data on bulb size are given in Table 3. Melano- phores occur in the roof of the cloacal tube just anterior to the common tube of the spermatheca and in the connective tissue surrounding the spermatheca.

In addition, the cloacal chamber of a November specimen contains the remains of a spermatophore cap (Fig. 6E, F). The cloacal recess contains some sperm and much globular material recognizable as male pelvic gland secretion (Fig. 6F). The area of the cloacal chamber ventral to the recess contains some pelvic gland secretion and much sperm.

In the specimen stained in Mallory's, 10-14 small glands occur just posterior to the common tube of the spermatheca in the connective tissue between the spermatheca and the roof of the cloacal tube (Fig. 6F). Diameters of 11 of these glands are 0.03-0.07 mm (x = 0.05 mm, SD x 10-2 = 1.10). The cytoplasm stains blue in Mallory's, and no discernible secretory product is present. The remaining S. marginatus lack these glands.

Pseudotriton montanus and P. ruber.- In both species, the largest ovarian follicles occur in summer collected individuals (Table 1). Four of the five females of P. montanus (79.0-81.8 mm SPVL) collected in August from South Carolina have ovarian follicles 1.8-2.8 mm in diameter. Sperm are present in the spermatheca in two of these specimens. The remaining individual (69.8 mm SPVL) from the same collection has follicles -0.5 mm in diameter and may be immature. The specimen collected from South Carolina in October has follicular diameters of 1.8- 2.4 mm, the Ohio specimen (August) has follicular diameters of 0.2-0.4 mm, and the Kentucky specimen (July) has follicular diameters of 0.5-0.8 mm.

For the P. ruber, the July collected specimen from Ohio has small ovarian follicles with diameters of 0.4-0.5 mm, but the North Carolina specimens from July and August have ovarian diameters of 2.6- 3.1 mm and 2.8-3.0 mm respectively. The July specimen from North Carolina is the only P. ruber female to possess sperm in the spermatheca. The March collected P. ruber has ovarian diameters of 0.4-1.0 mm, and the specimens collected in Oc- tober have ovarian diameters of 0.3-0.9 mm.

Females of these two species are similar in cloacal anatomy and different from G. porphyriticus and S. marginatus (Figs. 5C, 7). The urogenital ducts in both species merge with the gut near or at the anterior end of the vent. Thus, a cloacal tube is short or nonexistent (Fig. 7A). One P. montanus (81.3 mm SPVL) lacks a cloacal tube, and in three other females, the CTL/TCL quotients are 0.044 (68.3 mm SPVL), 0.111 (81.1 mm SPVL), and 0.112 (68.1 mm SPVL). Three P. ruber (65.2 mm, 75.9 mm and 88.8 mm SPVL) with countable sections lack a cloacal tube, while in another (88.7 mm SPVL), the CTL/TCL quotient is 0.01. Thus in these species, the spermatheca is generally a structure associated with the anterior one- fourth of the cloacal chamber (Fig. 5C).

Counts of spermathecal neck tubules and bulbs in P. montanus are 22 (68.3 mm and 69.8 mm SPVL), 30 (68.1 mm SPVL) and 34 (81.3 mm SPVL) and in P. ruber, tubule and bulb numbers are 18 (88.7 mm SPVL), 26 (75.9 mm SPVL), and 32 (65.2 mm and 88.8 mm SPVL). As in the other species, the epithelium lining the cloacal walls is stratified at the anterior end of the cloacal chamber, but in P. ruber and P. montanus, the epithelium of the common tube also is stratified (Fig. 7B). The epithelium of the neck tubules and bulbs, however, remains simple, although that of the bulbs is highly fluctated (Fig. 7B). Cilia are again absent throughout the cloaca.

The distal ends of most ventral glands extend into the posterior intestinal region, but as in the other species, these glands secrete on the tips of cloacal rugae ventral




A0,u fo A' an 15,u 4o -.Scintie

A.~~~~~~~~~~~~~~~~~~~'4

~~~ C~V q

FIG. 7. -Transverse sections through the cloacae of female P. montanus. Scale in lower right corner =

400 Am for A and 150 Am for B-D. Sections stained in hematoxylin-eosin. (A) Anterior end of the cloacal chamber in a female, 81.3 mm SPVL. (B) Same specimen as A, spermatheca. (C) Near posterior end of the spermathecal region in a female, 68.1 mm SPVL, showing absence of a recess. (D) Same specimen as A, showing dorsal glands along the common tube. Labels same as for Fig. 6 plus OV = oviducts.

to the spermatheca. The ventral glands are eosinophilic, positive with PAS and mercuric bromphenol blue, and some alcian blue positive granules occur in ventral glands of P. montanus. Counts for ventral glands are =46 (81.3 mm SPVL), =48 (68.1 mm SPVL) and =54 (68.3 mm SPVL) in P. montanus and =32 (88.8 mm SPVL), =40 (75.9 mm SPVL) and =46 (unknown SVL) in P. ruber.

Neck tubules of the spermathecae are short and do not vary greatly in length seasonally, intra- or interspecifically. The total range noted in four P. montanus and five P. ruber is 0.12-0.28 mm. Both the spermathecal bulbs and the ventral glands are reduced in those individuals in non- breeding condition (i.e., smaller eggs). Measurements of the ventral glands and

spermathecal bulbs in some specimens are given in Table 3.

No cloacal recess and thus no cloacal papilla exist in P. montanus or P. ruber (Figs. 5C, 7C). The cloacal rugae end posterior to the spermatheca, and the walls of the posterior one-half of the cloacal chamber are smooth and gradually shorten until even with the epidermis caudal to the vent.

Both species of Pseudotriton possess, however, distinct clusters of the "rudimentary" dorsal glands. These glands cannot be found in two P. montanus, but all other specimens of both species possess them. Generally 6-10 pairs of these glands occur, either along the common tube or just anterior or posterior to the common tube (Fig. 7B, D). These basophilic glands are PAS positive and slightly alcian blue positive. The dorsal glands are small and show little variation in size. Gland diameters from five P. ruber and two P. montanus are 0.03-0.09 mm (n = 38, x = 0.048 mm, SD x 10-2 = 1.28). This mean does not differ significantly from that obtained for dorsal glands in S. marginatus.

Finally, the Pseudotriton differ from the other species examined by lacking a concentration of melanophores in the connective tissue surrounding the spermatheca. A few melanophores can occur scattered throughout the cloacal lining, but essentially, the cloacae of these species are without black pigment.

DISCUSSION

The view that Gyrinophilus, Pseudo- triton and Stereochilus form the most primitive generic grouping in the family Plethodontidae is based primarily upon osteological characters (Wake, 1966). Clo- acal anatomy of these forms may also resemble an ancestral state, or species within these genera could possess a derived cloacal anatomy while retaining ancestral states in osteological characters. Determi- nation of the pleisomorphic state for plethodontid cloacal anatomy requires a knowledge of evolutionary trends in cloacal structure in plethodontids as well as in related groups of salamanders. Unfor- tunately, the comparative anatomy of clo-




acal anatomy within the Plethodontidae and presumed ancestral or sister groups of plethodontids is not well known enough to make definitive statements about the phylogeny of cloacal anatomy.

The Plethodontidae is believed to have shared a common ancestor with the North American family Ambystomatidae (Lar- son, 1984; Wake, 1966). The cloacal anatomy of ambystomatids is poorly known. The only reports are those of Kingsbury (1895), who described the cloaca of female Ambystoma maculatum, and Sever (1981), who described that of male A. tigrinum. No basis exists for believing that the cloacal anatomy of these extant Am- bystoma bears any resemblance to that of a hypothetical ancestor that gave rise to modern ambystomatid-plethodontid lines. Thus, it is not surprising that the cloacal anatomy of Gyrinophilus, Pseudotriton and Stereochilus resembles that of other plethodontids more than that of the Am- bystoma that have been studied. Male A. tigrinum, like male Gyrinophilus and Pseudotriton, possess only two divisions in their pelvic gland, but these divisions do not seem to be completely homologous between ambystomatids and plethodontids (Sever, 1983). Male A. tigrinum possess readily identifiable clusters of Kingsbury's glands, posterior ventral glands, and vent glands (Sever, 1981). Female A. maculatum have well-developed ventral glands and dorsal glands, but no common tube exists for the numerous spermathecal tubules (Kingsbury, 1895).

The genera examined in this study are in the plethodontid subfamily Plethodon- tinae, which includes members of the pu- tatively more advanced genera Eurycea and Plethodon. Males of Eurycea and Plethodon that have been examined possess relatively long cloacal tubes and well- developed dorsolateral pelvic gland clusters (Sever, 1978a, 1980). Males of the paedomorph E. tynerensis lack vent glands, but males of other paedomorphic Eurycea possess at least a homologue of the vent gland (Sever, 1985). Female Eu- rycea and Plethodon that have been studied also possess elongate cloacal tubes (Kohering, 1925; Trauth, 1983). Female

Eurycea possess ventral glands but lack dorsal glands (Sever, 1985). Female Pleth- odon lack cloacal glands other than the spermatheca. A cloacal papilla and recess occur at least in some eastern large Pleth- odon but are absent in other Plethodon and in Eurycea (Sever, 1978b, 1985).

Both sexes of the paedomorphic hemi- dactyliine Typhlomolge rathbuni differ significantly from Eurycea and Pletho- don. Male T. rathbuni lack dorsolateral pelvic glands, posterior ventral glands and vent glands. Female T. rathbuni possess a spermatheca and ventral glands and lack dorsal glands and a cloacal papilla and recess. Except for the lack of dorsal glands, the cloacal anatomy of female T. rathbuni is similar to that of P. ruber and P. montanus.

The cloacal anatomy of males of most species of salamanders in the plethodontid subfamily Desmognathinae is similar to that of male Eurycea and Plethodon except that desmognathines typically possess a dorsolateral recess in the posterior cloacal chamber (Sever, 1983). Male Phaeognathus hubrichti, however, lack dorsolateral and caudal pelvic gland groups, and male Desmognathus quad- ramaculatus and Leurognathus marmo- ratus differ from the typical desmogna- thine pattern in having a shorter cloacal tube and a reduced posterior ventral gland. The only reports on female desmogna- thine cloacal anatomy are brief descriptions for D. fuscus by Kingsbury (1895) and Noble and Pope (1929). No cloacal papilla or recess occur in this species, and no cloacal glands exist except for the spermatheca.

Based upon osteological characters, Pseudotriton and Gyrinophilus are more similar to one another than either is to Stereochilus (Wake, 1966). Cloacal anatomy does not follow a similar trend through both sexes. Female G. porphyriticus are more similar in cloacal anatomy to female S. marginatus than to either species of Pseudotriton. On the other hand, male G. porphyriticus and P. ruber have similar cloacal anatomy and differ markedly from the cloacal anatomy of S. marginatus.




The phylogenetic significance of these observations depends upon the underlying causes of similarity. If male P. ruber and G. porphyriticus are symplesiomorphic for cloacal anatomy, nothing can be inferred using this character about the branching patterns of these species from a common ancestor (Hennig, 1966). If, on the other hand, a cloacal recess is a derived state, the co-occurrence of that character in female G. porphyriticus and S. marginatus is synapomorphic, and thus evidence that these two genera are sister groups (Hen- nig, 1966). Because the ancestral and derived states are not known, however, my findings currently provide equivocal sup- port for the idea that Pseudotriton and Gyrinophilus are more closely related phylogenetically than either genus is to Stereochilus.

A more detailed cladistic analysis of relationships among these three genera using cloacal characters in conjunction with other characters is not presently warrant- ed. Further comparative study is needed to test my hypotheses of ancestral and derived states and to find additional cloacal structures of phylogenetic significance.

The results of the staining reactions for carbohydrates in the cloacal glands of male Gyrinophilus, Pseudotriton and Stereo- chilus are similar to those reported for other plethodontids (Sever, 1981, 1983, 1985). A postive test for proteins in the globular component of the pelvic glands has also been reported for Desmognathus, although the reactions are more intense in Desmognathus than in the species examined herein (Sever, 1983). The reaction of secretions of the vent gland in male G. porphyriticus and P. montanus to a pro- tein stain (mercuric bromphenol blue) has not been reported in other plethodontids. The same stains and tests used on the male cloacal glands can be used on spermatophores of these species to determine the function of each gland cluster in spermatophore formation (Sever and Houck, 1985).

From the discovery of portions of a spermatophore cap in the cloaca of a female S. marginatus, several functional correlates relating to sperm transfer can

be made. First, the pelvic gland probably secretes the dorsal border of the spermatophore cap, because globules in the male pelvic gland stain in the same manner as the cap border found in the cloacal recess of the female. Second, it appears that spermatozoa escape from the cap ventrally, perhaps through the area where the cap joins the base. Such a mechanism was hypothesized for Plethodon glutino- sus by Zalisko et al. (1984), who noted that the outer layers of the cap were discontin- ued in the area where the spermatophore cap and base joined.

Because the dorsal capsular material was in the cloacal recess and free sperm were noted in the cloacal chamber ventral to the recess, perhaps the function of the recess is to aid in the release of sperm from the spermatophore cap by pinching off the dorsal globular covering from the inner contents of the cap. On the other hand, the function may be merely to increase surface area of the cloacal chamber so that the entire cap can be drawn into the cloaca. If the sperm do escape from the ventral floor of the cap, the cap needs to be completely inside the cloaca. Confirma- tion of these or other alternative roles for the recess must await experiments such as those conducted by Sever and Houck (1985) with Desmognathus ochrophaeus. In that species, no recess exists in the female cloaca and the cap is not drawn completely into the cloacal chamber. In- stead, the capsular seal occurs ventrally, and sperm escape from the dorsal portion of the spermatophore cap, where a cap- sule of pelvic gland globules is lacking (Sever and Houck, 1985).

Brandon (1971) reviewed the evidence for paedomorphism in G. palleucus. He cited the discovery of mature larvae, including a male whose cloaca held a spermatophore and a female larva that con- tained large eggs. Brandon (1971) concluded that G. palleucus is normally paedomorphic, even though specimens readily and consistently undergo metamorphosis in response to thyroxin treatment. The type of paedomorphosis shown by G. palleucus has been characterized as neoteny: i.e., paedomorphosis as a result




of retarded somatic maturation (Bruce, 1979).

Although large larvae (77-119 mm SPVL) were examined, the only mature G. palleucus found was a naturally metamorphosed male (77 mm SPVL). The cloacal anatomy of this specimen was similar to that of male G. porphyriticus and P. ruber except that the cloacal tube was relatively longer. The cloacal anatomy of larval males and females was similar to each other and to descriptions of the cloacal anatomy of larval G. porphyriticus given by Dieckmann (1927).

It is likely that the spermatheca in females develops from the dorsal glands found in larvae and that the glands found around the anterior cloacal orifice of larvae develop into the female ventral glands, although observations necessary to con- firm this are lacking. It is more difficult to account for the development of the extensive and diverse male cloacal glands from the analagen found in large male larvae. Wilder (1925) stated that the male and female cloacal glands may be consid- ered derivatives of the integument and that they make their first appearance during metamorphosis. Cloacal glands, however, are well-formed in all other paedomorphic salamanders that have been studied (Dawson, 1922; Sever, 1980, 1985). A definitive study still needs to be done on the development of male and female cloacal glands.

Acknowledgments.-For aid in procurring specimens, I thank the following individuals: A. L. Bras- well, R. A. Brandon, R. C. Bruce, J. Jacobs, S. Perrill, N. L. Reagan, G. L. M. Smith, and A. Wynn. I thank N. L. Reagan and M. Turk for aid in preparation of some of the specimens.

LITERATURE CITED

BESHARSE, J. C., AND J. R. HOLSINGER. 1977. Gyri- nophilus subterraneus, a new troglobitic salamander from southern West Virginia. Copeia 1977: 624-634.

BRANDON, R. A. 1971. North American troglobitic salamanders: some aspects of modification in cave habitats, with special reference to Gyrinophilus porphyriticus. Nat. Speleolog. Soc. Bull. 33:1-21.

BRANDON, R. A., J. JACOBS, A. WYNN, AND D. M. SEVER. 1986. A naturally metamorphosed Gyri- nophilus palleucus. J. Tennessee Acad. Sci.:1-2.

BRUCE, R. C. 1979. Evolution of paedomorphosis

in salamanders of the genus Gyrinophilus. Evolu- tion 33:998-4000.

COPENHAVER, W. M., D. E. KELLY, AND R. L. WOOD. 1978. Bailey's Textbook of Histology, 17th Ed. Williams and Wilkens, Baltimore.

DAWSON, A. B. 1922. The cloaca and cloacal glands of the male Necturus. J. Morphol. 36:447-465.

DENT, J. N., AND J. S. KIRBY-SMITH. 1963. Meta- morphic physiology and morphology of the cave salamander Gyrinophilus palleucus. Copeia 1963: 119-130.

DIECKMANN, J. M. 1927. The cloaca and spermatheca of Gyrinophilus porphyriticus. Biol. Bull. 53: 258-280.

GROBMAN, A. B. 1959. The anterior cranial elements of the salamanders Pseudotriton and Gyri- nophilus. Copeia 1959:60-63.

HENNIG, W. 1966. Phylogenetic Systematics. Uni- versity of Illinois Press, Urbana.

HUMASON, G. L. 1979. Animal Tissue Techniques, 2nd Ed. W. H. Freeman, San Francisco.

KINGSBURY, B. F. 1895. The spermatheca and methods of fertilization in some American newts and salamanders. Trans. Am. Microscop. Soc. 17: 261-304.

KOHERING, V. 1925. The spermatheca of Eurycea bislineata. Biol. Bull. 49:250-265.

LARSON, A. 1984. Neontological inferences of evolutionary pattern and process in the salamander family Plethodontidae. Pp. 119-217. In M. K. Hecht, B. Wallace, and G. T. Prance (Eds.), Evo- lutionary Biology, Vol. 17. Plenum Press, New York.

MARTOF, B. S., AND F. L. ROSE. 1962. The comparative osteology of the anterior cranial elements of the salamanders Gyrinophilus and Pseudotri- ton. Copeia 1962:727-732.

NOBLE, G. K., AND S. H. POPE. 1929. The modification of the cloaca and teeth of the adult salamander, Desmognathus, by testicular transplants and by castration. J. Exp. Biol. 6:399-411.

SEVER, D. M. 1976. Morphology of the mental hedonic gland clusters of plethodontid salamander (Amphibia, Urodela, Plethodontidae). J. Herpetol. 10:227-239.

1978a. Male cloacal anatomy of Plethodon cinereus and Plethodon dorsalis (Amphibia: Pleth- odontidae). Herpetologica 34:1-20.

1978b. Female cloacal anatomy of Pleth- odon cinereus and Plethodon dorsalis (Amphibia, Urodela, Plethodontidae). J. Herpetol. 12:397-406.

1980. Cloacal anatomy of male brook salamanders (Eurycea). Herpetologica 36:51-60.

. 1981. Cloacal anatomy of male salamanders in the families Ambystomatidae, Salamandri- dae and Plethodontidae. Herpetologica 37:142-155.

. 1983. Cloacal anatomy of male salamanders in the plethodontid subfamily Desmognathi- nae. Herpetologica 39:16-27.

. 1985. Sexually dimorphic glands of Eu- rycea nana, Eurycea neotenes and Typhlomolge rathbuni (Amphibia: Plethodontidae). Herpeto- logica 41:71-84.

SEVER, D. M., AND L. D. HOUCK. 1985. Spermato- phore formation in Desmognathus ochrophaeus. Copeia 1985:394-402.




SIMMONS, D. D. 1976. A naturally metamorphosed Gyrinophilus palleucus (Amphibia, Urodela, Plethodontidae). J. Herpetol. 10:255-257.

TRAUTH, S. E. 1983. Reproductive biology and spermathecal anatomy of the dwarf salamander Eurycea quadridigitata in Alabama. Herpetologi- ca 39:9-15.

WAKE, D. B. 1966. Comparative osteology and evolution of the lungless salamanders, family Plethodontidae. Mem. So. California Acad. Sci. 4:1-111.

WILDER, I. W. 1925. The Morphology of Amphib- ian Metamorphosis. Smith College, Northampton, Massachusetts.

YEATMAN, H. C., AND H. B. MILLER. 1985. A naturally metamorphosed Gyrinophilus palleucus from the type locality. J. Herpetology 19:304-306.

ZALISKO, E. J., R. A. BRANDON, AND J. MARTAN. 1984. Microstructure and histochemistry of salamander spermatophores (Ambystomatidae, Sala- mandridae and Plethodontidae). Copeia 1985:739- 747.

Accepted: 19 September 1985 Associate Editor: Stephen Tilley

Herpetologica, 42(3), 1986, 323-334 ? 1986 by The Herpetologists' League, Inc.

REPRODUCTIVE BIOLOGY OF DESMOGNATHUS FUSCUS AND DESMOGNATHUS SANTEETLAH IN THE

UNICOI MOUNTAINS

R. L. JONES'

Graduate Program in Ecology, University of Tennessee, Knoxville, TN 37916, USA

ABSTRACT: In this paper, I compare the reproductive biology of Desmognathus fuscus and Desmognathus santeetlah from the Unicoi Mountains of eastern Tennessee and western North Carolina. Male D. santeetlah mature at approximately 30 mm snout-vent length (SVL); male D. fuscus mature at approximately 35 mm SVL. Males of both species show little seasonal variation in reproductive structures once sexual maturity is attained. Female SVL at maturity is 35 mm in D. santeetlah and 40 mm in D. fuscus. Males of both species mature at approximately 2 yr of age, females at approximately 3 yr. Oviposition in D. santeetlah peaks during June and mean clutch size is 21.3 ova. Mean clutch size in D. fuscus is 22.9 and oviposition takes place primarily in July. Mean clutch sizes of the two species differ significantly when corrected for SVL. Hatching in the laboratory occurs in 50-60 days in both species. Principal nesting sites of D. fuscus are beneath rocks along streambanks; D. santeetlah oviposit most commonly beneath mosses on rocks or logs in seepage areas. Differences in reproduction between the two species are as distinct as their genetic and morphological differences.

Key words: Amphibia; Caudata; Plethodontidae; Reproduction; Tennessee; North Carolina; Desmognathus fuscus; Desmognathus santeetlah

TILLEY (1981) described Desmogna- thus santeetlah from the Great Smoky, Great Balsam, and Unicoi Mountains of western North Carolina and eastern Ten- nessee. It is closely related to the relatively widespread D. fuscus, but the two species are both morphologically and genetically distinct. Several studies have dealt with the reproductive biology of D. fuscus (e.g.,

1 PRESENT ADDRESS: Mississippi Museum of Nat- ural Science, 111 North Jefferson Street, Jackson, MS 39202, USA.

Danstedt, 1975; Hall, 1977; Juterbock, 1978; Orser and Shure, 1975) whereas that of D. santeetlah is essentially unknown. Because the two species are closely related, they are expected to show many similarities in reproduction and in other life history traits. Given that life history traits are influenced by natural selection, inter- specific variation in these traits should provide insight into some of the selective pressures under which each species evolved. In this study, I compare the development of primary and secondary sex-



herpetologists' league - southeastern.edu · september 1986] herpetologica 301 wiley, e. 0....

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