BIOL 1114 Practical 3 Perch Anatomy

Spiny Dorsal Fin

The anterior dorsal fin containing sharp spines; functions for protection and balance

Soft Dorsal Fin

The posterior dorsal fin; helps keep the perch upright when swimming

Pectoral Fin

Helps steer the perch and control swimming depth

Pelvic Fin

Stabilizes the fish and provides balance; allows for up-and-down movement in the water

Caudal Fin

Propels the perch forward by providing power

Anal Fin

Provides stability

Operculum

Protects the gills; aids in pumping water over the gills when the fish is not moving to assist respiration

Anus / Cloaca

Exit from the digestive tract and opening for the sex organs

Liver

Regulates blood glucose levels; aids in digestion through enzyme excretion; assists with detoxification

Heart

Two-chambered with an atrium and a ventricle; single loop circulatory system where oxygenated and deoxygenated blood are not in separate pathways

Stomach

Receives food from the esophagus; breaks down food and absorbs nutrients

Intestine

Site of final digestion and absorption; relatively short because proteins from other fish are easy to break down

Gills

Allow the perch to breathe underwater via gas exchange; use countercurrent flow where water moves opposite to blood flow

Swim Bladder

Maintains buoyancy by adjusting the amount of gas it contains

Gonad

Sex organs; males have 2 testes for sperm production and females have 1 ovary for egg production

2

The perch heart has __ chambers

single loop

The perch has a __ circulatory system