within the lower sacramento and san joaquin rivers, delta and shoreline bay habitats identification...
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Within the Lower Sacramento and San Joaquin Rivers, Delta and shoreline Bay habitats
IDENTIFICATION OF FISHES
USFWS Juvenile Fishes
Monitoring Sites
General Anatomy
Mouth Structure
Dorsal and Anal fin ray counts
First rudimentary ray is not counted
Last ray is always treated as a double ray divided to the base of the fin
Lamprey Family, PETROMYZONTIDAE
Anadromous, some freshwater
Lampreys have a notochord and a cartilaginous skeleton
Do not have jaws or paired fins
Larvae, known as ammocoetes
Brook lamprey are nonpredaceous
Lamprey Lamprey AmmocoeteAmmocoete
Pacific Lamprey(PL)
Lampetra tridentata
Native Four pairs of
lateral tooth plates
Supraoral plate with 3 sharp cusps
Adult avg. TL = 400mm - 690mm
Anterior Teeth
Supraoral Plate
Lateral Tooth Plates
Transverse Lingual Lamina
River Lamprey(RL)
Lampetra ayresi
Native 3 pairs of lateral
tooth plates
Supraoral plate with 2 sharp cusps
Center cusp on transverse lingual lamina large
Adult avg. TL 170mm, never > 320mm
Anterior Teeth
Supraoral Plate Lateral
Tooth Plates
Transverse Lingual Lamina
Sturgeon Family, ACIPENSERIDAE
Heterocercal tail
Cartilaginous skeleton
Five rows of large bony plates instead of scales
Highly protrusible, bottom-oriented mouth preceded by four barbels
White Sturgeon(WST)
Acipenser transmontanusNative
Barbels are closer to tip of snout than mouth
No dorsal plates behind dorsal fin
1 row of 1 - 4 plates between pelvic and anal fins
38 - 48 lateral plates
Green Sturgeon(GST)
Acipenser medirostrisNative
Barbels closer to mouth than to tip of snout
1 - 2 dorsal plates behind dorsal fin
Two rows with 4 - 8 plates each between pelvic and
anal fins
23 - 30 lateral plates
Herring Family, CLUPEIDAE
Marine, anadromous and freshwater
Silvery deciduous scales and thin, deep bodies with a sharp keel on the belly.
Herrings have highly protractile jaws and long, fine gill rakers
Pacific Herring(PAH)
Clupea harengus
Native No black
spotting on sides
Origin of pelvic fins under midportion of dorsal fin
Teeth present on vomer (roof of mouth)
39 mm FL
American Shad(AMS)
Alosa sapidissima
Introduced Row of black
spots on sides
16 - 17 ventral scutes posterior to pelvic fin base
Length to 750mm TL
Threadfin Shad(TFS)
Dorosoma petenenseIntroduced
Thread-like projection at posterior edge of dorsal fin
8 - 12 ventral scutes posterior to pelvic fin base
One black spot posterior to operculum
Deeper bodied than American shad
Length to 220 mm TL
MYOMERE COUNT ON GUTAPPROXIMATELY 18-22
Threadfin Shad
MYOMERE COUNT ON GUTAPPROXIMATELY 30-35
American Shad
AMERICAN SHAD vs. THREADFIN SHAD
Photos: Rene Reyes
Anchovie Family, ENGRAULIDIDAE
Mostly marine
Overhanging snout
Long upper jaw extends behind the eye
Northern Anchovy(NAN)
Engraulis mordax
Native Snout
overhangs lower jaw
Origin of anal fin under or posterior to last few soft-rays of dorsal fin
Pectoral axillary scale more than half the length of pectoral fin
Salmon and Trout Family, SALMONIDAE
Native to cooler waters of the northern hemisphere
Possess an adipose fin and an axillary scale at the base of each pelvic fin
Eleven species native to California
Chinook Salmon(CHN)
Oncorhynchus tshawytscha
Native Numerous small
black spots on both lobes of the caudal fin in adults
6 - 12 parr marks are wider than spaces in between
Leading edge of anal fin is shorter than length of base
Adipose fin clear with dark upper edge in juveniles
Tail covered with spotsLong black spots on back and dorsal fin
13 - 19 rays
Coho Salmon(CHO)
Oncorhynchus kisutchNative
Anal fin is sickle-shaped, leading edge is longer than base
Adipose fin has dark pigment on anterior and dorsal margin only
8 - 12 parr marks are narrower than the spaces in between
Caudal, anal and adipose fins are pale orange
12 - 17 rays
Spots on upper caudal
Coho SalmonCoho Salmon
Chinook SalmonChinook Salmon
Base of teeth white Edge of gums black
Black on gums and base of teeth
Small eye
Rainbow Trout (Steelhead)(RBT)
Oncorhynchus gairdneri
Native Spots on dorsal
fin of fry 8 - 13 parr marks
are narrower than the spaces in between
Adipose fin has continuous rim of pigment in juveniles
First dorsal ray is black on fry
Uniform spots on tail
Square tail
Dorsal fin has black spots and black first ray, and a white tip
Adipose has continuous rim of black pigment
Anal fin has anteriormost ray about equal to the length of fin base
Anal fin is sickle-shaped, leading edge is longer than base
Leading edges of anal and dorsal fins have white followed by black
Adipose has black pigment on anterior and dorsal margins
Fins are pale orange
Anal fin has white leading edge and is not sickle-shaped, leading edge is shorter than base
Adipose has some black pigment on dorsal margin only
Dorsal fin has dark leading edge
Juvenile Salmonids of the Central Valley
13 - 19 rays
Chinook Salmon
12 - 17 rays
Coho Salmon
8 - 12 rays
Rainbow, Steelhead
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