Vertebrates
Characteristics Dorsal hollow nerve cord Notochord Pharyangeal gill slits (pouches) Post anal tail
Characteristics to Consider Poikilothermic vs. Endothermic Types of Reproduction Vertebrae structure Body Covering Economic Importance
Classes Hagfish (teeth of karatin, unpaired fins, cartiledge skull, no vertebrae, scavengers, produce liters of slime) Chondrichtheyes (sharks, skates, rays) Lampreys Ray-finned Lobe-finned Amphibians Reptiles Birds Mammals
Chondrichthyes Cartiledge skeleton, some calcified in scales and teeth. If stops swimming will sink (stores lots of oil in liver). Some rest on seafloor and must pump water across the gills Good vision but no color Nostrils for smelling Electric field sensation in skin of head Whole body senses “sound” Internal fertilization, eggs hatch inside of some sharks
Lobe-finned Rod shaped bones with thick muscles around pectoral and pelvic fins Rare fish, lungfish
Ray finned “Oesteichthyes” Ray finned: Calcium phosphate bone 5 pairs of gills with operculum Swim bladders to control boyancy Bony scales with mucus secreting glands Lateral line