Fishing for the Perch
Kiara Staton Vu PAP-Bio
Perch are carnivorous fish that are most commonly found in small ponds, lakes, streams, or rivers. These fish feed on smaller fish, shellfish, or insect larvae, but can be caught with nearly any bait. They commonly spawn during the spring, when the females lay strings of eggs in covered areas such as near branches or underwater plants. Even though Perch can be found all over the world, they are most likely found in the Great Lakes, Particularly in Lake Erie.
The important parts of the external anatomy are the fins of the fish and what they do to help the perch. The caudal in is used for propulsion, dorsal fins are used to protect the fish, the pectoral fin is a forelimb used to help with swimming, the anal fin is used to stabilize the fish while it is swimming, and the pelvic fin is used to assist the fishes up and down movement.The general body type of a perch is somewhat long and rounded. True perch have "rough" or ctenoid scales. On the anterior side of the head are the maxilla and lower mandible for the mouth, a pair of notsrils, and two lidless eyes. On the posterior sides are the opercula, which protect the gills, and the lateral line system, which is sensitive to vibrations in the water. They have paired pectoral and pelvic fins, and two dorsal fins, the first one spiny and the second soft. These two fins can be separate or joined.
The external anatomy also includes important parts such as the operculum. This part of the fish is used to cover the gills and help the perch with its breathing. Another important feature is the lateral line that are specialized scales that are sensitive to vibrations in the water. This allows the fish to be alert when there are predators near by.
The internal anatomy is very intricate. To first get a peak at the gills a line had to be cut around the entire fish. The gills are made out of 4 soft almost un-noticable layers that are feathery in appearance.
The most important factors of the internal anatomy are the heart which has both a ventricle side that receives messages and the atrium which sends messages. The next part of high importance is the swim bladder, this helps for the fish to maintain its buoyancy.
Just the Basics
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. Venous (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. Thus the blood makes a single circuit during which it is pumped, oxygenated, and distributed to the body, before it returns to the heart. In this pattern of circulation the heart pumps only deoxygenated blood.
The heart has a heavy membrane separating the pericardial and abdominal cavities. It is termed the transverse septum. The fish heart consists of four distinct parts. Posterior to anterior (in the same direction as blood flow) these are the sinus venosus, atrium, ventricle and bulbus arteriosus .parts are not arranged in a straight line, but have folded over one another to produce a S-shaped organ. The top of the S, the sinus venosus, receives blood from two common cardinal veins and the hepatic sinus. The sinus venosus is thin walled and opens directly into the atrium. The atrium is equivalent to the paired atria of higher vertebrates. It is thicker walled and larger than the sinus venosus. The ventricle itself is a thick muscular structure. Like the atrium, it has a single internal chamber. Backflow of blood from the ventricle during contraction is prevented by a valve. The last portion of the perch heart is the bulbus arteriosus. The bulbus arteriosus is really an enlarged, very muscular portion of the ventral aorta, the vessel in which blood flows away from the heart and toward the gills. Backflow of blood from the bulbus arteriosus is also prevented by the presence of valves.
Perch the Predator
The perch likes to eat worms, small fish, nymphs and larvae, as well as many of their own small perch. Perches are carnivorous fish, and have a diet that consists of many different food sources.
Hooked on Facts
- When threatened the perch raises these fins as a defense against being eaten. The spines on the fins are extremely sharp and can inflict a painful wound.
- Perch like to hang out around weed beds but will move into deep water as the shallow water warms.
- Perch will suspend in deep water but are generally found within a foot or two of the bottom.
- Perch are carnivorous and will eat just about any kind of creature they can get their mouth around. They will eat other fish, crawfish, snails, insects, worms, fresh water shrimp and fish meat.
- Perch spawn in the spring when the water temperature is between 44 and 55 degrees. They generally spawn at night. Depending on its size, a perch will spawn between 4,000 and 40,000 eggs.
- Perch belong to the Percidae family of fish and are closely related to walleye and sauger. All of the species of this family are spiny-rayed and have two well separated dorsal fins. The first fin (closest to the head) has the most spines.