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Lecture 9 . Monday, September 15, 2008. 1. Details on basal Actinopterygiians a. bichirs - Polypteriformes b. sturgeon & paddle fish - Acipenseriformes c. gar - Semionotiformes d. bowfin - Amiiformes 2. Review material to date. Class Actinopterygii - the ray-finned fishes.
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Lecture 9. Monday, September 15, 2008. 1. Details on basal Actinopterygiians a. bichirs - Polypteriformes b. sturgeon & paddle fish - Acipenseriformes c. gar - Semionotiformes d. bowfin - Amiiformes 2. Review material to date.
Class Actinopterygii - the ray-finned fishes Acipenseriformes Polypteriformes Semionotiformes Amiiformes Teleostei Semiontiformes = Lepisosteiformes
Order Polypteriformes - bichirs Unique characters • 5 to 18 separate finlets- each with a spine and soft rays
Order Acipenseriformes - sturgeons and paddlefish Polypteriformes Acipenseriformes Semionotiformes Amiiformes Teleostei
Family Acipenseridae - sturgeon link to Carol’s website
Family Acipenseridae = grave conservation situation, several species near extinction
Family Acipenseridae • Sturgeons are the largest fishes found in freshwaters • beluga sturgeon -27 ft, 1,800 lbs. • recreational fishery for more common species still a viable industry
sturgeon video • http://www.youtube.com/watch?v=daoPehLwed8
Family Polyodontidae • Snout not developed in juveniles
Family Polyodontidae • Two species • Polyodon spatula - Mississippi River Drainage of eastern United States • Psephurus gladius-China, Yangtze Drainage
Family Polyodontidae • Polyodon spathula - biology • Filter feeder, zooplankton, mouth non-protrusible
Class Actinopterygii - the ray-finned fishes Polypteriformes Acipenseriformes Semionotiformes Amiiformes Teleostei
Family Lepisosteidae • Fossils
Order Semiontiformes - gar • Heterocercal tail
Order Semiontiformes - gar • Vascular air bladder
Order Semiontiformes - gar • habitat
Family Lepisosteidae - biology • Spawn in late spring over shallow vegetated areas • Female accompanied by multiple males, eggs broadcast over substrate • Eggs are large, adhesive, & poisonous. Adhere to vegetation • Larvae hatch with adhesive disk at tip of lower jaw, attach to vegetation until yolk sac is absorbed
Family Lepisosteidae - biology • Reach maturity at 3 yrs, can live up to 20 yrs. • Piscivores - lie-in-wait predators • Most species average 2 - 3 ft. in size, alligator gar can reach 10 ft.
Family Lepisosteidae - biology • Of seven known species, four known to occur in Illinois
spotted gar eating a fish http://www.youtube.com/watch?v=BXuQL8HKgoE
Order Amiiformes • One extant family, Amiidae • one extant species - Amia calva
Order Amiiformes • Amia calva • Long dorsal fin, aids in propulsion • Heterocercal tail
Order Amiiformes Amia calva - biology • Life span ~10 years • Can reach 2.5 - 3 ft. in length
Group Activity #1 -Draw the phylogenetic tree & distinguishing traits for: group a - Myxiniformes, Gnathostomata, Chondrichthyes, Teleosts group b - Petromyzontiformes, Elasmobranchii, Holocephali, Sarcopterygii, Actinopterygii group c - Elasmobranchii, Holocephali, Sarcopterygii, Teleosts group d - Myxiniformes, Petromyzontiformes, Chondrichthyes, Osteichthyes
Group Activity #2 - Rotate at least 2 nodes of the tree and draw it again. Group Activity #3 - Design a dichotomous key that would allow one to distinguish these groups For example . . . Step 1 - lacks vertebrae --> Myxiniformes if not --> go to step 2 Step 2 - lacks jaws --> Petromyzontiformes if not --> go to step 3
Group Activity Number 4: Describe the general pattern in the evolution of the following: group a - evolutionary transition from jawless to jaws group b - evolutionary transition from no paired fins to paired fins group c - a possible explanation for the evolution of reproduction/offspring development in Elasmobranchii group d - evolution of scales Group Activity #5: For the same groups . . . describe the implications of these evolutionary transitions.
Group Activity #6 - Describe the evolutionary transitions of the following: a) evolution of caudal fin shapes. b) evolution of lungs/swim bladders. c) evolution of the role of the maxilla and pre-maxilla in eating. d) evolutionary loss of the spiral valve What are the possible implications of these changes for fishes?
For each of the following taxa, list at least 3 details about their biology : group 1: hagfish, Acanthodii, hammerhead, skates, basking shark bichirs, black carp group 2: lampreys, chimaeras, manta ray, electric rays, Coelacanth, sturgeon, common carp group 3: Ostracoderms, whale shark, sting ray, great white, Australian lungfish, bowfin, grass carp group 4: Placoderms, thresher shark, sawfish, megamouth, S.A. & African lungfish, paddlefish, silver & bighead carp