Pondering Perch Dissection

Perch Dissection Lab by Katherine Lee; Vu P1

Objectives

The purpose of the perch dissection is for one to find a better understanding of the external and internal anatomy of a perch. Students will take a close look at the organs and functions of the circulatory system.

Background Information of a Perch

Taxonomy:


  • Kingdom- Animalia
  • Phylum- Chordata
  • Subphylum- Vertebrata
  • Class-Actinopterygii
  • Order- Perciformes
  • Family- Percidae
  • Genus- Perca
  • Species- flavescens


Predator-Prey Relationship:

Perch will feed on microorganisms that reside in the lakes, ponds, or streams where they live. Adult yellow perch feed on insect larvae, crustaceans, and small fish. Perch are common prey to larger fish-eating fish such as the northern pike, bowfins, lake trout, large mouth and small mouth bass, and walleye. They also serve as food to birds including herons, gulls, and eagles.


Habitat & Niche:

A perch is best suited to an area of clear water with sand and gravel bottoms and a moderate amount of vegetation. Most live in lakes or other places where freshwater is present. Larval perch tend to remain in tributaries but will move offshore to reduce the risk of predators. As youth they move back to shorelines to feed on richer food sources. Adults inhabit nearshore areas where vegetation can provide food and protection.


Adaptations:


  • Perch have specialized teeth known as palatines that are used to eat other small fish such as young large mouth bass and minnows.
  • Perch feed by sight which is why they possess large eyes.
  • Their body shape is thin, shorter, and disc-shaped that makes them agile around rocks and weeds and makes them harder for predators to swallow.
  • Striped body for camouflage that helps them hide in weeds for protection or to attack prey.
  • Their lightly colored belly is less visible to predators below it.


Did you know?


  • Hatching occurs only 11-27 days after fertilization depending on the temperature of the water.
  • Perch have scales rough to the touch.
  • They have two dorsal fins: one armed with long, sharp spines, and only the first spine of the second fin is sharp
  • Perch prefer water temperatures of 66-70 degrees Fahrenheit.
  • Yellow perch is the most frequently caught game fish in Michigan.
  • Male perch reach sexual maturity at about 3 years old and females at two or three.
  • The oldest white perch found in Maryland's portion of the Chesapeake Bay was fifteen years old.

Circulatory System of a Perch

Perch have a closed circulatory system meaning that its blood travels through a network of blood vessels. Fish exhibit single cycle circulation where the oxygen deprived blood comes to the heart, from where it is pumped to the gills and then throughout the entire body.

  • Two-chambered heart: the organ that pumps blood through the perch's entire body.
  • Atrium: Thin wall layer in the heart that aids in the circulation of blood.
  • Ventricle: Thick wall layer in the heart that aids in pumping blood through the body.
  • Blood: Blood comes to the heart from the sac-like structure known as the sinus venosus where it passes to the atrium. It then enters the ventricle from the atrium. A bicuspid valve between the atrium and ventricle prevents blood from flowing back into the atrium when the ventricle contracts. Blood flows from there to the bulbous arteriosus, a muscular tube, to the ventral aorta.
  • Ventral aorta: Where blood flows to the gills from.
  • Arteries: A blood vessel responsible for carrying oxygenated blood from the heart to the rest of the body.
  • Veins: Blood vessel that returns deoxygenated blood from the different parts of the body to the heart.
  • Capillaries: Thin-walled blood vessels that lie between arteries and veins that allow gases and nutrients to pass out of the blood to the individual cells.