biology of fishes env 422/nre 422/eeb440 · construct a cladogram that includes the following...
TRANSCRIPT
Craniate Relationships Biology of Fishes
9.13.2012
Review
Morphology
Classification
Phylogenetics Assignment
Craniate Relationships
Overview
Basic Fish Morphology
Classification
Rank-based system (Linnaean)
Evolutionary history-based system (Phylogenetics)
Phylogenetics
Apomorphies, synapomorphies, plesiomorphies
Monophyly, paraphyly, polyphyly
Review
Basic Fish Morphology
Rank-based (Linnaean system, traditional)
Kingdom - Animalia
Phylum - Chordata
Class - Actinopterygii
Order - Perciformes
Family - Percidae
Genus - Perca
Species - flavescens
Classification
Yellow Perch
Construct a cladogram that includes the following groups:
Holostei (Gars & Bowfins)
Chondrostei (Sturgeons & Paddlefishes)
Dipnoi (Lungfishes, tetrapods)
Teleosts (“modern” bony fishes)
Cladistia (Bichirs)
Actinistia (Coelacanths)
Phylogenetics Assignment
A B C D E F
SARCOPTERYGII
ACTINOPTERYGII
Phylogenetics Assignment
Characteristics
Possess a braincase (differentiates from tunicates and cephalochordates)
Other synapomorphies
Neural crest
Complex sense organs & cranial nerves
Muscularized gut wall, differentiated digestive organs
Respiratory gills, heart, and hemoglobin
Muscles to draw in water for feeding & respiration
Craniate Relationships
Craniate Relationships
Chondrichthyes
Osteichthyes
Sarcopterygii
Actinopterygii
Vertebrates
CR
AN
IATE
S
Hagfishes
Vertebrates
Lampreys
Gnathostomes (possess jaws)
- Chondrichthyes (cartilaginous fishes)
- Osteichthyes (bony fishes)
Sarcopterygii (lobe-finned fishes)
Actinopterygii (ray-finned fishes)
Craniate Relationships
Hagfishes
Vertebrates
Lampreys
Gnathostomes (possess jaws)
- Chondrichthyes (cartilaginous fishes)
- Osteichthyes (bony fishes)
Sarcopterygii (lobe-finned fishes)
Actinopterygii (ray-finned fishes)
Craniate Relationships
Hagfishes (Myxiniformes)
Most “primitive” of living or fossil craniates
Sister group of all other craniates
~50 species, all marine
No larval stage
Benthic scavengers, lack jaws
Possess 1 semi-circular canal
Lack paired fins & vertebrae
Craniate Relationships
Hagfishes
Vertebrates
Lampreys
Gnathostomes (possess jaws)
- Chondrichthyes (cartilaginous fishes)
- Osteichthyes (bony fishes)
Sarcopterygii (lobe-finned fishes)
Actinopterygii (ray-finned fishes)
Craniate Relationships
Vertebrates
Possess vertebrae
At least 2 semi-circular canals
Radial fin muscles
Craniate Relationships
Craniate Relationships
Chondrichthyes
Osteichthyes
Sarcopterygii
Actinopterygii
Vertebrates
CR
AN
IATE
S
Hagfishes
Vertebrates
Lampreys
Gnathostomes (possess jaws)
- Chondrichthyes (cartilaginous fishes)
- Osteichthyes (bony fishes)
Sarcopterygii (lobe-finned fishes)
Actinopterygii (ray-finned fishes)
Craniate Relationships
Lampreys (Petromyzontiformes)
~40 species described
Found in marine & freshwater
Larval stage (ammocoete) filter-feeds from sediments in streams (~3 years)
Most species parasitic as adults (use of rasping tongue); other species do not feed as adults
Sea Lamprey (Petromyzon marinus)
Craniate Relationships
Hagfishes
Vertebrates
Lampreys
Gnathostomes (possess jaws)
- Chondrichthyes (cartilaginous fishes)
- Osteichthyes (bony fishes)
Sarcopterygii (lobe-finned fishes)
Actinopterygii (ray-finned fishes)
Craniate Relationships
Gnathostomes (Gr., gnathos = jaw + stoma = mouth)
Possess jaws
3 semi-circular canals
2 sets of paired fins
Paired nostrils
5 gill slits
Gill arches
Craniate Relationships
Hagfishes
Vertebrates
Lampreys
Gnathostomes (possess jaws)
- Chondrichthyes (cartilaginous fishes)
- Osteichthyes (bony fishes)
Sarcopterygii (lobe-finned fishes)
Actinopterygii (ray-finned fishes)
Craniate Relationships
Craniate Relationships
Chondrichthyes
Osteichthyes
Sarcopterygii
Actinopterygii
Vertebrates
CR
AN
IATE
S
Chondrichthyes (Gr., chondros = cartilage + ichthyos = fish)
Calcified cartilaginous skeleton (calcium salts form prismatic plates – tesserae Latin “tile”)
Placoid scales – tooth-like with dentine and enamel or enamel-like covering
Males possess claspers; inserted into cloaca of female for internal fertilization
Teeth continuously replaced or bony plates grow continuously
Craniate Relationships
Elasmobranchii (Gr., elasmos = thin plate + branchia = gills)
Includes sharks, skates, and rays
~800 species
Mostly marine, some truly freshwater
Smallest – dwarf lantern shark, largest – whale shark
Thin plates of connective tissue that bear the gills
Rays separated from sharks by their enlarged pectoral fins; grow forward and fuse to head during ontogeny
Chondrichthyes
Elasmobranchii (sharks, rays, and skates)
Chondrichthyes
Holocephali (Gr., holos = whole + kephale = head)
Chimaeras or ratfish
~30 speceis
Marine, mostly deepwater
Single gill opening
Males have a spiny clasper-like organ on head to grab female during copulation
Venomous predorsal spine
Chondrichthyes
Hagfishes
Vertebrates
Lampreys
Gnathostomes (possess jaws)
- Chondrichthyes (cartilaginous fishes)
- Osteichthyes (bony fishes)
Sarcopterygii (lobe-finned fishes)
Actinopterygii (ray-finned fishes)
Craniate Relationships
TELEOSTOMI
Teleostomi (Gr., teleos = terminal + stome = mouth)
Includes Acanthodi (extinct) and Osteichthyes (bony fishes)
Terminal mouth
Bony operculum
Branchiostegal rays
Osteichthyes (Gr., osteon = bone + ichthyes = fishes)
The bony fishes
~29,000 species
Well-ossified (bony) skeleton
Lungs (eventually gas/swim bladder)
Craniate Relationships
Osteichthyes
Hagfishes
Vertebrates
Lampreys
Gnathostomes (possess jaws)
- Chondrichthyes (cartilaginous fishes)
- Osteichthyes (bony fishes)
Sarcopterygii (lobe-finned fishes)
Actinopterygii (ray-finned fishes)
Craniate Relationships
Craniate Relationships
Chondrichthyes
Osteichthyes
Sarcopterygii
Actinopterygii
Vertebrates
CR
AN
IATE
S
Sarcopterygii (Gr., sarkodes = fleshy + pteryg = wing or fin)
Fleshy or lobe fin fishes
Includes living and extinct fish-like forms and the terrestrial vertebrates
Marine and freshwater forms
Lobe fins – supported by bones and muscle outside body
Enamel on teeth
Craniate Relationships
Coelacanths (Actinistia)
One genus Latimeria (2 species)
Strictly marine, inhabits depths 500-2300 feet
Intracranial joint – joint in head that increases gape
Believed to have been extinct until one was discovered in 1938 of east coast of South Africa
Multiple morphologies in fossil record
“Living fossil” current form ~400 mya
Sarcopterygii
Coelacanths (Actinistia)
Sarcopterygii
Latimeria chalumnae Rebellatrix sp.
Lungfishes (Dipnoi)
Once classified as amphibians – tetrapods?
Freshwater tropical* rivers and lakes
Swim or crawl on bottom with lobed fins
Tooth plates for crushing food
African lungfish (Protopterus, 4 species)
South American lungfish (Lepidosiren paradoxa)
Australian lungfish (Neoceratodus forsteri)
Sarcopterygii
Lungfishes (Dipnoi)
African lungfishes
Order: Lepidosireniformes
Family: Protopteridae
Genus: Protopterus
Sarcopterygii
Lungfishes (Dipnoi)
South American lungfish
Order: Lepidosireniformes
Family: Lepidosirenidae
Species: Lepidosiren paradoxa
Sarcopterygii
Lungfishes (Dipnoi)
Australian lungfish
Order: Ceratodontiformes
Family: Ceratodontidae
Species: Neoceratodus forsteri
Sarcopterygii
Craniate Relationships
Evolution of various apomorphies
General group characteristics
Adaptations to various environments
Summary