Bony Fish/ Fish Terminology Flashcards
Jawed bony fish taxonomy
Class = Osteichthyes
Split into:
- ray finned fish
-lung fish
3 main adaptive strategies of propulsion
- Widely dispersed food = cruising and little energy expenditure to cover large area e.g. butterfly fish
- Abundant food that can escape = us bush predation e.g. tuna
- Food that cant escape, but complex habitat = maneuvreability e.g. barracuda
Describe the adaptations for locomotion type 1
- laterally compressed body
- high manoeuvrability
- fins cover nearly whole body (except mouth) and are large relative to body size
- low tension in fins
- small protrusible mouths
- spines for defence of pelvic and dorsal fins
Describe the adaptations for locomotion type 2
- evenly distributed fins for stability and manoeuvrability
- fuse form, streamlined body
- terminal mouth
- forked tail, narrow/average peduncle
Describe the adaptations for locomotion type 3
- large gape (gap between top and bottom lip)
- ventrally placed pectoral fin
- small pectoral and pelvic fins relative to body size
- posteriorly placed median fins (dorsal and anal)
- thick caudal peduncle
- flexible, torpedo like body
Name the different fish fins
Dorsal. = on top Caudal = tail Anal = back, underneath Pelvic = underneath middle Pectoral = middle side, front
How have fins changed over time
Primitive fish fins: provide lift and manoeuvrability
Modern fish fins: just to move
Pectoral has moved from underneath fish to on the sides
. Also used to be much larger to provide lift
Pelvic has moved further forward
Difference between bony and cartilaginous fins
As fins aid manoeuvring, flexibility is less important = can harden
Fins supported by rays support:
- moving
- defence
Spines =
- rigid
- never segmented
- often for defence
Rays
- flexible
- often branched
- mainly for support
Name the different shapes
Rounded e.g. flounder, butterfly fish
- aspect ratio = 1
Truncated e.g. salmon
- aspect ratio = 3
Forked e.g. herring
- aspect ratio = 5
Lunated e.g. tuna
- aspect ratio = 7+
Heterocercal e.g shark
- aspect ratio = variable
Superior mouth
Point down
Bottom of water column
Inferior/ sub terminal mouth
Point up
Top of water column
Terminal mouth
In the middle of the water column
Different types of scales
Placoid
Ganoid
Cycloid
Ctenoid
Placoid scales
E.g. sharks and rats
Overlapping riblets = streamlined
Scalloped edges = anti predator function
Ganoid scales
E.g. paddlefish
- abutting not overlapping
- hardened and rigid = protection
- primitive style of scale
