Ichthyology

The study of fish

Phylum chordata characteristics

Dorsal hollow nerve chord, notochord, pharyngeal pouches, tail

Class Agnatha

Jawless Fish (Lamprey/Hagfish)

Class Chondricthyes

Elasmobranchs, Cartilaginous (Sharks/Rays)

Elasmobranch characteristics

Cartilage skeleton, gill slits, jaws, paired fins

Class Osteichthyes

Teleosts/Bony fish (Trout/Salmon)

Bony fish characteristics

Gills,scales,bone

Pelagic

Live in upper water

Benthic

Live on the seabed

Demersal

Live just above seabed

Fusiform

Streamlined shape of most bony fish

Laterally compressed

Flattened from side to side, occurs in most reef fish

Depressiform

Flattened from top to bottom, most flatfish

Cycloid/ctenoid scales

Common scales in most bony fish

Circuli

Ring-like ridged scales

Annuli

Groups of circuli formed each winter, which age can be determined by

Operculum

Bony flap which protects gills

Superior mouth position

Surface feeder

Terminal mouth position

Omnivore, middle feeder

Inferior mouth position

Bottom feeder

Location of peduncle

Muscular part of tail between dorsal and caudal fin

Function of caudal fin

Locomotion and manoeuvring

Function of pectoral fins

Steering and braking

Function of swim bladder

Flotation/ buoyancy

Pyloric caeca

Pouch-like extensions which increase surface area for digestion/absorption

How many divisions of fish are there?

3 (Jawless, Bony, Cartilaginous)

Claspers

Male reproductive organ in elasmobranchs which transfers sperm

Oviparity

Birth embryos in an egg sac

Viviparity

Give birth to live young

Detritus feeders

Organisms which feed on decomposed organic material e.g sturgeon

Gill filaments

Thin projections used for gas exchange

Gill rakers

Used to protect gills and contribute in feeding

Gill lamellae

Made up of primary and secondary gill filaments

Spiracles

Holes in heads of Elasmobranchs which lead to gills

RAM ventilation

When a fish must keep moving to keep a constant flow of water over the gills (sharks)

Main parts of fish nervous system

Brain, spinal chord, nerves

Afferent arteries

Going to gills, low in oxygen

Efferent arteries

Goes away from gills, high in oxygen

Anterior cardinal

Vein which brings blood from head

Posterior cardinal

Vein which brings blood from rest of body

Fish white blood cell types

Lymphocytes, leukocytes

Fish red blood cells

Erythrocytes

Function of the lateral line

Sensory system which picks up on vibrations in the surrounding water column

Most prominent characteristic of bivalves

Double hinged shell

Umbo

First part of bivalve shell to develop

Adductor muscles

Powerful muscles which keep the shell of a bivalve closed

Mantle

Soft tissue layer which covers the body of a bivalve

Gill type examples

Protobranch, filibranch

Function of labial palps

Sort food prior to entering

Retractor muscles function

Operate the animal's foot

Function of the crystalline style

Grinds/churns food in the stomach

Function of the gills

Gas exchange

Haemolymph

Blood-like fluid which transports nutrients, gases and waste

How many heart chambers do bivalves have?

3

Types of ganglia of the nervous system

Pedal, cerebroplural, visceral

Sensory system organs

Ocelli, statocysts

How long is the pelagic life stage of mussels

30 days

Byssal threads

Structures that fasten a mussel to the substrate

Hermaphroditic

When an organism alternates between male and female throughout it's life

Name of shellfish larvae after the trochophore stage

Veliger larvae