EEB267H1 Lecture Notes - Lecture 5: Great White Shark, Chondrichthyes, Shark
19 Jan 2017
School
Department
Course
Professor
Document Summary
Includes sharks, and skates and rays: about 509 species. Stiffened with tesserae to different degrees based on feeding ecology: the ceratohyoid articulates with the lower jaw, helping to push it upwards. No operculum covering gills cartilaginous rays are lost on the hyoid arch completely. Sharp upper teeth reach surface of the food, slashing it. Eyes roll tail-ward in their sockets to protect them from injury: spike and swallow. Grabbing something and swallowing feeding on whole fishes. Detecting movements in the water lateral line: very old: lamprey, hagfish also have lateral lines, along the head and side of body. Detecting bioelectrical fields: ampullae of lorenzini: detect weak electrical fields from prey items, works well when prey is within a few cm (not a long distance sense) incredibly sensitive, operates day or night. Reproduction in chondrichthyes claspers fertilization is internal in all cartilaginous fishes: copulation in the water.
