Bony & Cartilaginous fish defintions

Operculum

Gill cover

Swim bladder

Gas-filled sac for buoyancy and respiration

Ganoid scales

Derived from bone
Little overlap, relatively heavy

Cycloid scales

Contains no bone
Circular scales with smooth outer edges and overlap

Ctenoid scales

Contains no bone
Small teeth along their outer edges; overlapping

Dermal denticles/placoid scales

Tiny scales with a pointed tip directed backward
Reduces hydrodynamic drag

Fusiform

Tapered at both ends; streamlined body shape to move through the water

Laterally compressed

Good for swimming around reefs and still allow for speed

Unpaired fins

Dorsal, Caudal, Anal
Generate forward thrust

Paired fins

Pectoral, Pelvic, Anal
Used to maneuver

Body Caudal Fin Propulsion (BCF)

Swim using lateral movements of their body and caudal fins

Median or Paired Fin Propulsion (MPF)

Swim using their median/paired fins

Undulatory locomotion

Wave-like movement patterns that act to propel and animal forward

Anguilliform

Undulations that are equally distributed along the length of the body

Carangiform

Some undulations along the body, most movement towards the rear of the fish

Thunniform

Undulations are focused in the tail

Heterocercal

Having unequal upper and lower lobes, usually with the vertebral column passing into the upper

Homocercal

Having symmetrical upper and lower lobes (most bony fish)

Physostomous fishes

Have a pneumatic duct between the gut and swim bladder

Physoclistous fishes

Lack a pneumatic duct

Fecundity

The ability to produce an abundance of offspring

Ceratotrichia

Soft, unsegmented fin rays

Countershading

Coloration pattern with upper surfaces darkly pigmented and sides and ventral surfaces silvery or only lightly pigmented

Tesserae

Hexagonal plates found in parts of the skeleton to add strength

White muscle

Fast contractions
Less force
Small muscles

Red muscle

Slow contractions
More force

Larger muscles

Claspers

Paired, sausage-shapes intermittent organs located along the inner margins of the pelvic fins of male shakes

Oviparous

Egg-laying, with little or no other embryonic development with the mother

Viviparous

Give birth to live young; pups attach to mothers blood supply via an umbilical cord and develop in uteri

Ovoviviparous

Eggs develop inside the female; female gives birth to live young (most sharks)

Oophagy

Developing embryos feed on a steady supply of tiny, unfertilized eggs

Adelphophagy

The largest pup in the litter will consume the embryos of its siblings

Parthenogenesis

Females reproduce asexually, producing a genetic clone

Euryhaline

Can thrive in fresh and salt water

Rostrum

Anterior prolongation of the head

Regional endothermy

The physiological ability to maintain elevated internal temperatures in specific organs

Flicker Fusion Frequency (FFF)

An indicator for the ability to resolve events in time
Warm: higher FFF
Cold: lower FFF

Caudal finlets

Reduce turbulence and improve stability

Peduncle

Muscular area where the tail attaches to the body

Caudal Keel

Lateral ridge, anterior to each side of the tail fin

Improves stability during high speed

Ram feeding

Accelerate toward prey, open their mouths wide and engulf their target

Clavus

A distinctive truncated tail fin on sunfish that is rounded and rudder-like