Chondrichthyes 0.0 / 5 ? zoologySharks, Rays, Skates and Chimeras UniversityNone Created by: phoeberbCreated on: 15-05-19 23:40 Key characters of Chondrichthyes Prismatic endoskeleton calcification Pelvic claspers Gill coverings, separate and uncovered Underslung mouth 1 of 12 Features of prismatic endoskeleton calcification Tesselate (overlapping) Polygonal (prismatic) 2 of 12 Where does prismatic calcification occur? Occurs on the cartilage skeleton Occurs in the placoid scales which cover shark skin 3 of 12 What part of sharks are calcified? Endoskeleton Placoid Scales- 70% calcified enameloid, 90% calcified dentin 4 of 12 Features of the teeth Form whorls developing teeth line up behind functional teeth Formed from dentin tooth replacement weekly in young sharks 5 of 12 Hyostylic jaw features Jaw directly attached to the cranium Upper jaw capable of protruding out Ethmopalatine ligament enables protrusion 6 of 12 Features of gill openings Seperate and uncovered Usually 5 pairs breathing via ram ventilation or buccal pumping 7 of 12 Ram ventilation Vs Buccal pumping Ram ventilation- Water is drawn in through the mouth is blown out of gills when the mouth is closed Buccal pumping- gill slits are blown open when water passes through the mouth sharks can switch between both 8 of 12 Filter feeding features Gill rakers- pass food trapped in gill slits to the oesophagus Rakers made of keratin Three species of filter feeders- megamouth, whale, basking shark 9 of 12 Features of pelvic claspers Claspers inserted into the female cloaca Sperm travels into cloaca via groove Male can wrap around female or lie parallel 10 of 12 Coelomic cavity features Divided into two parts by a transverse septum anterior pericardial cavity- heart and related viscera posterior peritoneal cavity- internal organs and other viscera 11 of 12 Heart Single circulatory system Heart chambers in a series- ventricle then atrium. 12 of 12
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