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Perch Dissection
1.) The perch is part of the Kingdom Animalia, Phylum Chordata, Class Actinopterygii, Order Perciformes, Family Percidae, and Genus Perca.
2.) Some characteristics of sub-phylum vertebrata are cephalization, the development of sensory structures, and the invertebrate column of the skeletal units that enclose the nerve cord. They also have a closed circulatory system with a ventral heart divided into two or more chambers. They have a maximum of two pairs of limbs, one pair of eyes and paired kidneys.
3.) The four classes of fish are Class agnatha, Class placodermi, Class chondricthyes, and Class osteichthyes.
Class Agnatha is made up of lampreys and hagfishes. They have the oldest vertebrate fossils.
Class Placodermi is extinct. This class was made up of armored fishes with paired fins and hinged jaws. These were extremely important, even evolutionarily.
Class Chondricthyes are sharks and their relatives. The general characteristics of sharks are that they have jaws, paired fins, and flexible skeletons made of cartilage. Most of them have a unique body. Their tails are asymmetrical and there body is dorsoventrally flattened. They also have placoid scales. Theses are derived from the dermis, which is denser than water. This means that they will usually sink if they stop swimming. Most sharks are carnivorous and they have short digestive tracts. Their digestive track has a spiral valve and acute senses.
Class Osteichthyes are bony fishes. Most are numerous of the vertebrates.Their general characteristics are that they have a bony skeleton and skin covered by flattened bony scales. Their glands are in skin secrete mucus, which reduces drag during swimming. Their gills are located in gill chambers covered by the operculum and the swim bladder. They are flexible and have very maneuverable fins and fusiform bodies.
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Janet Govea, ME
Part 1:
The coloration of the dorsal and ventral surfaces of the perch help protect it from its predators. The perch is dark colored, so that when it is viewed from the top it helps camouflage with the dark environment. When the perch is viewed from the bottom or its ventral surface when it is close to the surface of the water the coloration of the ventral surface camouflages with sun's light. There predators cannot see them when they blend in so well with the light in the water.
The function of the Claudal fin is to provide the main power for forward movement. The function of the anal fin and the dorsal fin is to stabilize the animal against rolling and assist in sudden turns. The function of the pelvic fin is to help control the direction of movement. The function of the pectoral fin(s) is to control the up and down movement.
The lateral line is a series of pores that are connected to canals beneath the skin. These pores serve as a motion detector
Bony fishes have a closed circulatory system.
The function of the swim bladder is to balance the fish in water. It keeps the fish stable and keeps it from floating straight to the surface.
The sex of the perch that we dissected was male because no eggs or ovaries could be found.
Part 2:
The goldfish's operculum opened 51 times in 60 seconds.
If there was less oxygen in the water the operculum would have to pump faster in order to obtain more oxygen.
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The spawning technique of the female perch is simple. The female perch releases her eggs into the water where they are externaly fertlizied.
The perch was about 8 inches in length, and was dark in color. The dorsal side was almost black in thick lines, but the ventral side was a lot litter. The perch eats throughout most of the day and breeds on occasion. They are aquadic, but they are normally found in lakes.
The perch could move to a different environment or feed on different organisms in a deeper body of water.
The perch might eat insects, worms and algae.
The agressiveness of the perch can keep it from being caught. When the fish is more determined to get away, it will do anything to escape.
A perch's life purpose is to reproduce. Before they reproduce all they do is eat and grow. The perch reproduces each year.
The perch eats by opening its mouth and grabbing on to its prey. Food is eaten in one gulp. They do not chew their food, they tear it into smaller pieces which can be consumed. Once the food has passed through the mouth, it passes into the esophagus and then into the stomach where it is partially broken down. The food is further processed in the pyloric caeca, which secretes the digestive enzymes in order for the nutrients from the food to be absorbed. The small intestine then is able to absorb the remaining nutrients. Digestive enzymes from several other organs aid in the breakdown of the food in the small intestine. Any remaining or unprocessed food is released through the anus.
Respiration is accomplished trhough theperch's gills. In the gills, oxygen can be filtered from water. The oxygen is then released into the heart where the bloodstream can distribute the gas.
Movement is achieved through swimiming and the locomotion of the caudal fin. With the aid of the swim bladder the perch is able to control its depth.
Reproduction occurs in perchs externally. The female perch lays her eggs in a designated area where a male predecessor can fertilize them by releasing sperm.
The perch excretes solid wastes through the anus. Then the material is released into the water. Nitrogenous waste created for cellular metabolism is filtered out by the perch's kidneys. It is then released with other solid wastes through the anus.
The perch responds to pressure, by using the lateral line system. When provoked by predators the perch is normally able to swim away swiftly by using its caudal fin.
The perch that was dissected was a fresh water fish that can be found in lakes. Perchs eat smaller organisms such as insects, filter feeders and other small invertebrates. They help control the population of these organisms. In turn the perch is also eaten by mammals and other large vertebrates.
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This lab was not as much fun as the worm and the crayfish, and it smelt worse, but I think I learned more. I thought that there was going to be a lot more organs, or at least bigger organs in the fish than there were. Most of the fish was just meat. The gills were very similar looking to those of the crayfish, but the other organs seemed smaller and more squished together. Janet and I had a hard time disecting the fish without cutting into any of those organs, but we made it. Some of the gills we sliced as we diseccted too. The skin around those areas was very tough. All in all, the dissection was a success, though. We completed what we needed to and I learned some interesting new facts.
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I learned a lot in this lab because there was a lot of information to be absorbed The most interesting thing that I learned was why the perch is the color that it is. I think it is neat that they blend in with the light on the surface of the water or in the shadows of the water, so that there predators cannot see them. In this lab I demonstrated competencies, 10a, 11g, and 11i. In my lab group, I drew 3 pictures, helped gather information, and helped dissect It was hard when Denisha joined our group since we were already into the lab, but we included her too. I think next time, we should be a little bit more precise on where we are dissecting the fish, but I did feel that our group got this lab done faster than any of our others, which has been our goal.
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COS = 3
Conventions = 2
Total = 5
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