Perch Dissection Introduction

The Perch Scientific Name: Perca flavens Size: About 0.3m long and up to 2.3 kg Range: Found in lakes and rivers from the Great Lakes to the Atlantic coast and as far south as South Carolina Habitat: Lives concealed among vegetation Diet: Feeds on insect larvae, crustaceans, and other fishes Reproduction: Female perch lay strings of eggs that are fertilized externally and the young hatch within days

Anatomical terms Anterior: In front of, front Posterior: After, behind, following, toward the rear Dorsal: Near the upper surface, toward the back Ventral: Toward the bottom, toward the belly Superior: Above, over Inferior: Below, under Lateral: Toward the side, away from the mid-line Medial: Toward the mid-line, middle, away from the side Rostral: Toward the front Caudal: Toward the back, toward the tail

Label the arrows as Anterior, Posterior, Dorsal, or Ventral

Important External Perch Body Parts to Know anal fin - the fin on the lower side of the body near the tail caudal fin - the tail fin dorsal fin - the fin on the upper side of the body – Spinous Dorsal =anterior dorsal – Soft Dorsal = Posterior Dorsal pectoral fin - each of the paired fins on either side of the body, near the head ventral fin (Pelvics) - each of the paired fins on the lower side of the body, near the head

Important External Body Parts to Know lateral line - a series of sensory pores (small openings) that are located along the sides of fish -they sense vibrations in the water mouth - the part of the body which the fish uses to catch food - it is located at the front of the body eye - sight organs located on the head gills - fleshy organs that are used for breathing - they are located on the side of the head Operculum- is a hard plate that is attached to each side of the head, that covers the gills and is open at the rear. Aids in gas exchange Nostrils- Lead to the olfactory sacs, helps fish smell

Internal Body Parts of the Perch Mouth - the first part of the digestive system, where food enters the body. Chewing in the mouth is the beginning of the digestive process (breaking down the food). Esophagus - the long tube between the mouth and the stomach, the anterior portion of the digestive tract; it carries food to the stomach. Stomach - a sack-like, muscular organ that is attached to the esophagus. When food enters the stomach, it is churned in an acid bath. intestine - Section of the digestive tract between the stomach and the anus where absorption of nutrients is carried out and waste is transformed into fecal matter. Anus - the opening at the end of the digestive system from which feces exit the body.

Internal Body Parts of Perch Gall bladder - a small, sac-like organ It stores and releases bile (a digestive chemical which is produced in the liver) into the small intestine. liver - a large organ located above and in front of the stomach. It filters toxins from the blood, and makes bile (which breaks down fats) and some blood proteins. Kidney- organ that eliminates metabolic waste and maintains the pressure of internal fluids. Heart- muscular organ helping blood to circulate, the fish has a two chambered heart made up of the atrium and ventricle

Internal Body Parts of a Perch Spinal cord - component of the nervous system made up of a soft fatty substance and forming a cylindrical stem inside the vertebral column vertebral column – movable bony axis made up of various parts articulating with each other (vertebrae); it supports the skeleton and contains the spinal cord. Muscle- muscular segment of the posterior portion of the body; its zigzag arrangement contributes to efficient motion. Swim Bladder- used to regulate their vertical position in the water by controlling the amount of gas that is in the swim bladder.