A FISHY DISSECTION
The Perch, Perca fluviatilis, is a freshwater 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 CIRCULATORY SYSTEM
The circulatory system of a Yellow Perch is a low pressure, single loop system. This means that there is one direction of blood flow from the heart, which acts as a pump. Deoxygenated blood is pumped throughout the heart and goes onward to the gills. This is where the blood becomes oxygenated (the gills), getting rid of carbon dioxide. From here the blood goes straight to the body. This makes up one single circuit of the blood flow: Blood pumped à Oxygenated à distributed throughout the body à returns to heart. Blood pumped from the heart in this type of circulation is purely deoxygenated.
Types of circulation in Yellow Perch:
· The Branchial Circulation- blood enters through the gills of the Perch from the afferent branches of the ventral aorta and circulate through the afferent and efferent branchial arteries to the dorsal aorta
· Systemic Circulation- this type of circulation in the fish is in charge of sending nourishment to all of the tissues within it except the heart because it has it's own circulation; this occurs towards the stomach of the fish
· Closed System- Due to the Perch having a closed system, in a single loop within the fish the circulation continues from heart to gills to organs then back to the heart
There are five main components to the Perch’s circulatory system. The first is the two chambered heart which consists of four parts: sinus venosus, the atrium, the ventricle, and the bulbus arteriosus. The heart keeps the blood flowing and pumping through the fish keeping the blood circulating in a single loop. Fish are constantly moving or swimming to maintain blood pressure. There are only one ventricle and atrium in the Yellow Perch, creating two chambers. There are many arteries with in the Yellow Perch these include: efferent branchial arteries, afferent branchial arteries, the ventral aorta, intestinal artery, gonadal artery, pneumatic artery, dorsal aorta, and the celiac artery. Blood enters the gills of the fish from the afferent branches of the ventral aorta. The aorta (ventral and dorsal) are the largest arteries in the fish, and distribute oxygenated blood. The veins inside the Yellow Perch consist of: the hepatic portal vein, intestinal vein, left posterior cardinal vein, and right posterior cardinal vein. Veins deliver deoxygenated blood to the heart. There are very many different nutrient rich capillaires branching off of the arteries and veins in the Yellow Perch. Capillaries are in charge of distributing oxygenated blood from arteries to the tissues of the body and to send deoxygenated blood from these tissues back into the veins. They are the smallest of these three types of blood vessels (arteries, veins, capillaries). The gills of the fish are extremely important to its circulation because this is where the blood becomes oxygenated.
Due to the Yellow Perch living in water and having different fins and gills, allows the fish to maintain it's blood pressure by constant movement in the water. If the fish was not able to maintain this pressure, it would not be able to survive with it's single looped system.
- Their method of spawning is unique in that female yellow perch lay their eggs in long gelatinous strands, usually floating or hanging from vegetation or some other structure.
- Yellow perch are found in approximately 13,000 acres of lakes and ponds, with tributaries to Chesapeake Bay furnishing considerably more water area.
- The world record yellow perch (18 in., 4 lb. 3 oz.) was caught in 1865 from New Jersey, and is the longest standing record for freshwater fish in North America
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Lilley, Phil. "Missouri State Record Yellow Perch | Field & Stream." Field & Stream. 07 May 2009. Field and Stream. 09 Apr. 2014