TERMS Marine Biology: Unit 6: Fish

Vertebrae

Backbone segments

Anadromous

Migrate from saltwater to freshwater

Catadromous

Migrate from freshwater to saltwater

Chondrichthyes

Class Name of cartilaginous fish

Ovoviviparity

Eggs hatch inside the mother

Viviparity

Live birth

Spiracles

Small openings for water intake

Spiral valve

Intestinal fold for digestion

Gills

Organs for underwater respiration

Squalene

Oil aiding buoyancy in sharks

Ampullae of Lorenzini

Electroreceptors in sharks/rays

Elasmobranchs

Subclass of Chondrichthyes/Cartilaginous fish

Heterocercal

Unequal lobes in fish tail

Caudal fin

Tail fin, helps with movement, propels

Claspers

Male reproductive organs in sharks/rays

Oviparity

Egg-laying reproduction

Lateral line

Sensory system detecting water movement

Dorso ventrally compressed

Flattened from top to bottom

Dorsal fin

Back fin for stability

Pectoral fins

Side fins for maneuvering

Pelvic fin

Lower paired fins, stability

Chimaera

Deep-sea cartilaginous fish

Operculum

Gill cover for protection (only in bony fish)

Sarcopterygii

Lobe-finned fish

Actinopterygii

Ray-finned fish

Ganoid

Thick, bony fish scales

Cycloid

Smooth, round fish scales

Ctenoid

Rough, comb-edged fish scales

Fusiform

Torpedo-shaped body

Laterally compressed

Flattened from side to side

Horizontally compressed

Flattened from top to bottom

Globular

Round-shaped body

Chromatophores

Pigment-containing skin cells

Iridophores

Reflective skin cells

Disruptive coloration

High-contrast patterns for camouflage

Cryptic coloration

Blending with surroundings

Obliterative coloration

Dark top, light underside

Buoyancy

Ability to float

Swim bladder

Gas-filled organ for buoyancy

Hermaphroditism

Both male and female reproductive organs

Synchronous

Both sexes at the same time

Sequential

Changing sexes over time

Protogyny

Female to male

Protandry

Male to female