Module 13: Fish Osteology

Question 1

Class

Answer 1

Pisces

Question 2

Orders and families

Answer 2

Agnatha (jawless fish)
• Cyclostomata (hagfish and lampreys)
Chondrichthyes (cartilaginous fish)
• Elasmobranchii (sharks and rays)
• Holocephali (chimaeras and extinct relatives)
Osteichthyes (bony fish)
• Actinopterygii (ray finned fishes)
• Sarcopterygii (fleshy finned fishes, ancestors of tetrapods)

Question 3

Fish bones

Answer 3

Flat and pointy
Translucent/shiny
Lightweight

Question 4

Bony vs cartilaginous fish

Answer 4

Bony
-bilaterally flattened
-primarily bone skeleton
-skull-numerous bones, only central fused cranial complex found usually
-ray finned fish-rays of bone in fins
-lobed finned/fleshy finned fish-one bone supporting articulation of fin to body
Cartilaginous
-dorso-ventrally (DV) flattened
-cartilage skeleton primarily
-vertebra, maxilla, mandible, dental plates, barbs/spines only bones left

Question 5

Bony fish

Answer 5

Trunk vertebra have neural spine (on top) and 2 transverse processes (bottom) for articulation w pleural ribs
Caudal vertebra have neural spine and heamal spine (bottom)

Question 6

Distinct features

Answer 6

Some fish have highly distinct cranial complexes
Hardhead/sail/saltwater catfish has cruciform complex

Question 7

Cartilaginous fish

Answer 7

Neural arch, transverse processes, haemel spine all cartilaginous
Indentations in circumference of these vertebrae