Animals with some back bone & some without Chordates Animals with some back bone & some without

Characteristics of Chordates Notochord a rod of vacuolated cells, encased by a firm sheath that lies ventral to the neural tube in the vertebrate embryos and some adults Hollow nerve cord that lies dorsal to the notochord Pharyngeal pouches become gills in fish Post-anal tail an extension of the body past the anal opening *Endostyle elongated groove in the pharynx floor of protochordates that may develop as the thyroid gland in chordates

In the subphylum Vertebrata, all members possess the 4 chordate characteristics at some time during development. The structures can be greatly altered in the adult animal

Protochordates Phylum Hemichordate Ancesters of the chordates which may or may not possess some or all of the 4 characteristics, living representatives are also called protochordates. Phylum Hemichordate Enteropneusta (acorn worms) 2 cm to 1.5 m long shallow marine waters, in mud or vegetation solitary filter feeders well developed gill slits and a stomocord (once thought to be a notocord) have a dorsal strand of nerve cells (pre-dorsal hollow nerve cord)

Protochordates Pterobranchia tiny, deep sea colonial, moss-like no dorsal nerve cord or notocord one pair of gill slits

Protochordates Phylum Balanoglossus possess gill slits dorsal nerve cord; also has a ventral nerve cord, the nerve cords are not hollow. worldwide, shallow seas few cm up to 2 meters

Subphylum Urochordata Tunicates/sea squirts organism enclosed in a tough, cellulose-like tunic (hence the name) primitive vertebrate metamorphoses from mobile larva to a sessile adult notocord and tail get resorbed adult and larva differences larval possess gill slits, nerve cord and notocord tadpole-like, free-living. Larval stage last only a few days until it finds an appropriate attachment sight then it metamorphoses Adult is sessile, siphons water to obtain food. http://www.umanitoba.ca/faculties/science/biological_sciences/lab13/images/tuniclarv.jpeg

Adult tunicates

Subphylum Cephalochordata Amphioxus one organism-”Amphioxus” means sharp at both ends 5-8 cm live on the sea shore fish-like appearance has a laterally compressed dorsal fin incomplete organs no bony structures show cephalization

Subphylum Vertebrata actively-feeding allows for predatory behavior most move by lateral undulation of an elongate body

Classes of vertebrates Agnatha-jawless fish hagfish-order Myxiniform will self knot to remove slime coat lampreys-order Petromyzontiform sucker fish, parasites to fish

Chondrichthyes (elasmobranchia) cartilagenous fish sharks no swim bladders scavengers and hunters whale shark is the largest fish (15m) usually have 5 gill slits salty as or more salty than sea water one type of scale tail is called cercal because of its irregular shape. found in all seas placoid

Chondrichthyes skates and rays skates rays flat-bodied rounded tail in warm and temperate seas broad, flattened bodies eyes on upper surface, mouths on lower counter-shading filter and regular feeders pointed tails

Osteichthyes bony fish swim bladders protrusible jaw no spiral valve usually 4 gills conserve water in kidneys 3 types of scales operculum ganoid cycloid ctenoid

Reptilia marine reptiles Tetrapods Turtles Green (sea) Loggerhead Hawksbill Leatherback Olive ridley Kemp’s ridley Flatback

Reptilia marine reptiles tetrapods Turtles Loggerhead Green (sea) Hawksbill Leatherback Olive ridley Kemp’s ridley Flatback Crocodiles Alligators Marine lizards sea snakes Galapagos Marine Iguana

Mammalia Mammals characteristics warm blooded hair placenta, mostly (viviparous) mammary glands brain is largest compared to body size of all vertebrates

Mammalia orders Carnivora - polar bears, sea otters, sea minks Sirenia - manatees and dugongs Cetacea - whales, dolphins and porpoises Odontocetae - toothed whales Mysticetae - baleen whales Pinnipedia - sea lions, seals, walruses

Aves birds Adaptations Buoyancy Heat loss Diving Migration Senses

Aves Types Stilt – Legged Terns and Skimmers

Aves Types Gulls Cormorants Pelicans

Aves Types Frigate Birds Penguins Pelagic Birds http://video.google.com/videosearch?q=Frigate+Birds&num=10&so=0&hl=en&start=20 Penguins Pelagic Birds