One Gilled Critter of the Sea

by: Hannah Katz teacher: Ms. Vu

The Perch

Perch fish are freshwater species belonging to the family Percidae. There are many types of perchs such as: Anabas testudineus (Climbing perch), Perca fluviatilis (European perch)Perca schrenkii (Balkhash perch), Perca flavescens (Yellow perch), Macquaria ambigua (Golden perch), Bidyanus bidyanus (Silver perch), Leiopotherapon unicolor (Spangled perch), and Morone americana (White perch). They are found in ponds, lakes, and rivers since they are freshwater. They are either omnivorous or herbivorous. They feed mostly on planktonic crustaceans. Aquatic insect larvae, corals are also a part of their diet.

Circulatory System

The circulatory system of the perch is a typical low pressure single type system in which the heart is a single pump and there is a single circuit of blood flow. Deoxygenated blood from the body is pumped through the heart forward to the gills. From the gills, where it is oxygenated, the blood goes directly to the body. Then the blood makes a single circuit during which it is pumped, oxygenated, and distributed to the body, before it returns to the heart. The heart is a double pump and there are two circuits of blood flow, systemic and pulmonary. In this type of system, blood is pumped through the heart twice. Deoxygenated blood from the body is pumped to the lungs where it is oxygenated (pulmonary circulation). Oxygenated blood from the lungs returns to the heart whereupon it is pumped to the rest of the body (systemic circulation). So the heart pumps both oxygenated and deoxygenated blood.