130 likes | 423 Views
Petromyzontidae (lampreys). Jawless 7 gill apertures No paired fins (pectoral, pelvic anal) Cartilaginous skeleton. American brook lamprey ( Lampetra appendix ). Petromyzontidae. Adults usually fish predator/parasites Sea lamprey adversely affected Great Lakes fishery
E N D
Petromyzontidae (lampreys) • Jawless • 7 gill apertures • No paired fins (pectoral, pelvic anal) • Cartilaginous skeleton American brook lamprey (Lampetra appendix)
Petromyzontidae • Adults usually fish predator/parasites • Sea lamprey adversely affected Great Lakes fishery • Ammocoetes (eyeless, no buccal disk) eat organic matter in sediments Sea lamprey (Petromyzon marinus)
Acipenseridae(sturgeons) • Large size • Subterminal mouth • Shovellike • Barbels • Bony plates on body (few scales) • Heterocercal caudal fin
Acipenseridae • Benthic feeders • Many species threatened • Overharvesting • Habitat degradation • Long generation time • Eggs used for caviar Shovelnose sturgeon (Scaphirhynchus platorynchus)
Polyodontidae(paddlefishes) • Large size • Long, paddlelike snout • Smooth skin (no scales or plates) • Heterocercal caudal fin • Skeleton mostly cartilaginous Paddlefish (Polyodon spathula)
Polyodontidae(paddlefishes) • Planktivorous • Paddle a sensory device? • Numbers greatly reduced • Good food quality • Long generation time
Lepisosteidae(gars) • Cylindrical body • Long jaws with teeth • Body covered with ganoid scales • Caudal fin modified heterocercal type
Lepisosteidae(gars) • Piscivorous; ambush predators • Inhabit vegetated areas • Eggs toxic to homeotherms • Commercially unimportant Longnose gar (Lepisosteus osseus)
Amiidae (bowfins) • Cylindrical body; up to 0.6 m long • Terminal mouth • Cycloid scales • Long dorsal fin • Black spot at base of caudal fin • Caudal fin modified heterocercal type Bowfin (Amia calva)
Amiidae (bowfins) • Preys on variety of aquatic animals • Inhabits wetlands and backwaters of rivers • Lunglike gas bladder • Unpalatable flesh