BIOL211 Lecture Notes - Lecture 7: Photobacterium, Tetrapodomorpha, Chondrostei

• School: University of Waterloo
• Department: Biology
• Course: BIOL211
• Professor: Dayeh Vivian

Document Summary

There are more species of osteichthyes than any other class of vertebrates for the last 150 million years >30000 species. Two subclasses of osteichthyes: actinopterygii , sarcopterygii , bony fish fin characteristics. The actinopterygians and sarcopterygians differ in fin structure. Ancestral osteichthyan fins have a row of basals that interact with the limb girdle. Followed radials and then followed by the fin rays. The fin rays support the web of the fin. The fins of actinopterygian have lost the basals and the radials attach to the limb girdles. The fins of sarcopterygians have a single basal that articulates with the limb girdles. The two bony fish groups differ in their skull anatomy and feeding mechanisms. They also differ in how their brains develop inward versus outward cerebral hemisphere folding. Most extant bony fish scales are fairly thin . 2: actinopterygii (ray-finned fishes, polypteriformes (order in subclass chondrostei) Includes the bichirs and reedfishes from africa.