Anatomy of a Fish Study Guide

Used to propel the fish forward; helps with swimming in a side-to-side motion

At the tail end of the fish

Filters waste from the blood

In the dorsal region of the body cavity

Helps the fish maintain its upright position in water; may be split into anterior and posterior parts

On the top (dorsal) side of the fish

Helps with flotation and buoyancy control

Inside the body cavity above the digestive organs

Transports food from the mouth to the stomach

Tube connecting the mouth to the stomach

Protects the gills and helps with breathing by allowing water to flow over the gills

Covers the gill area on the sides of the fish's head

Sensory system that detects water pressure and movement

Runs along the sides of the fish from head to tail

Protect the fish; contain growth rings that can determine a fish's age

The age of the fish by counting growth rings, similar to tree rings

Allow fish to extract oxygen from water; site where blood becomes oxygenated

Under the operculum on both sides of the head

A two-chambered heart

Pumps blood over the gills where it becomes oxygenated before returning to the body

Used for steering and maintaining balance

On the underside of the fish, posterior to the pectoral fins

Helps with digestion and processes nutrients

Inside the body cavity, usually large and centrally located

Where food is digested

Where digested food is absorbed and waste is passed to exit the fish

Esophagus → stomach → intestine → anus

Produce eggs or sperm for reproduction

Helps maintain upright position in water, similar to the dorsal fin

On the ventral side, between the anus and the caudal fin

Used for steering and balance when swimming

On the sides of the fish, just behind the operculum

A single-loop circulation system

Blood leaves the heart → goes to gills → becomes oxygenated → circulates through the body → returns to the heart

Summer growth with good food supply

Winter growth with limited food supply

Count the number of annual rings (one summer + one winter = one year)

When the fish was first born (as a fry)

The most recent periods of growth

Fish swim in a side-to-side motion, while aquatic mammals swim with an up-and-down motion

The dorsal fin and the anal fin

Pectoral and pelvic fins

They have a double-loop circulation system, while fish have a single-loop system

Jawless fish (Agnatha & lampreys), Cartilaginous fish (sharks & rays), Bony fish (thousands of species, goldfish, minnows, trout, etc.)

The study of fish

Scales

A scaly fish

No, some fish only have bare skin

Salmon swim from ocean to river spawning areas

Freshwater, Ocean (marine), Aquatic (general term for water environments)

Fish breathe with gills

Fish takes in water through mouth, pushes it through gills. Gills extract oxygen from water as part of the blood stream, deoxygenated water pushes out of gills.

A fish has a complete circulatory system. The heart pumps blood through gills where oxygen is collected and distributed to the body.

No, some fish have lungs too (in addition to gills)

Specialized organ filled with air that helps ensure fish maintains a stable buoyancy in the water, neither sinking or floating too much

To maneuver and maintain stability

Dorsal fins reduce rolling motion and aid in turning

Help with stability and control during swimming

Sexual reproduction

Female drops eggs in water, male immediately fertilizes them

Yes, in some circumstances males will fertilize eggs before the female drops them

A visible line along the side of a fish consisting of a series of sense organs which detect pressure and vibration

Human food, Wild fishing, farmed aquaculture, Part of the food chain, Pets and aquariums

Anterior (front), posterior (back/tail), dorsal (top), ventral (bottom)

Another word for this is "ectotherm"