Phylum Chordata

Subphylum Vertebrata

Marine Fishes

3 Classes

Class Agnatha - jawless fish

Class Chondrichthyes - cartilaginous fish

Class Osteichthyes - bony fish

Subphylum Vertebrata

Backbone (notochord)

Spinal cord (nerve cord)

Bilateral symmetry

endoskeleton

Body Shape

1. Oval – streamlined, fast, pelagic

2. Laterally compressed – fast bursts, agile

3. Flat fish – slow, benthic, smooth

4. Elongated – rocky, algae areas

5. Truncate – slow, primary consumer

Camouflage

Color and texture

Used for concealment

Coloration –

1. Warning coloration (venom)

2. Cryptic coloration (camouflage)

3. Disruptive coloration (breaks up outline)

4. Countershading (open water)

External Anatomy

Food

1. Algae eater – grazer, herbivore

2. Filterfeeder – water column, omnivore

3. Bottom feeder – invertebrates, small fish,

carnivore

4. Hunter – small to large fish, water column,

carnivore

Digestion

Mouth Esophagus Stomach

Intestine Anus

Liver and Pancreas present

Spiral valve in cartilaginous fish – increases

surface area

Circulatory System

Gills Body Heart Gills

2 chambered heart

Veins and arteries present

Respiration

1. Cartilaginous fishes

-need to move

-open/close mouth

2. Bony Fishes

-pressure change mouth

and operculum

-open and close both in

rotating pattern

Nervous System

Central Nervous system w/ brain and spinal

cord

-lateral line – sense organ (vibrations in H2O)

-Ampullae of Lorenzini – sense organ, head of

cartilaginous fishes (vibrations, electric field

Reproduction

Sexual reproduction

internal and external

Hermaphoroditic – some sequential

hermaphrodites

Development

1. Oviparous – lays eggs (bony fish)

2. Ovoviviparous – eggs develop inside

female, birth live young (cartilaginous fish)

3. Viviparous – embryos absorb nutrients

from female (cartilaginous fish)

Behavior

Migration –

1. Anadromous – migrate to fresh water to breed

2. Catadromous – migrate to salt water to breed

Homing behavior – ability of an animal to find its

way to home area

Behavior

Territory – home area, breeding, food

– Aggressive behavior – fights are rare

Schooling behavior – full time/part time

-protection against predators

-more common in bony fish