Crucian Carp Lab Report

Abstract

The crucian carp is an actinopterygii fish which is known to possess a swim bladder and non-muscular lobed fins. These fishes are also known as ray finned fishes. The fish contains the organs responsible for the digestion, respiratory, circulatory and nervous system. In order to observe the internal organs of the fish, the fish firstly is euthanasiated with clove oil. The external anatomy of the fish has five fins; pectoral, pelvic, dorsal, anal and caudal fin, a cloaca is located right behind the anal fin and this is where the cut is made until the beginning of the head. The fillet is removed to expose the internal organs. The crucian carp anatomy is similar to that of the other vertebrates. The fish contains most of the internal …show more content…
The reason for the fish to be dissected is because the external anatomy does not give insight into what the body contains, we can only observe the fins that are used for buoyancy as well as horizontal swimming, the lateral line system that is used to detect predators and prey was also visible. In this study the fishes that were used were not killed but they were sick. Firstly, the specimen was euthanized with clove oil. Euthanasia is a process whereby an animal is injected with a substance that will end its life in order to relieve pain. Scissors were used to the fillet from the cloaca until right below the pectoral fin, after the fillet was removed the internal anatomy of the fish was exposed. The first visible organ to be removed was the spleen which is dark red and made it easier to remove the male gonads. The first gonad was removed by cutting cleanly at both ends then the tissue at the top was moved in order to access the second gonad. The digestive tract which consists mainly of the esophagus, stomach which contained plant material, pyloric caeca, intestine and anus, were removed as a whole. The gall bladder and the liver were removed individually and were not removed with the digestive tract. The gall bladder was filled with a green fluid known as bile. The heart was then removed with care as to not puncture it. The swim bladder was also visible and was removed by cutting its ends with a sharp scissor. The kidney was removed but did not come out as a discrete tissue and it was located on the ventral surface of the spine. In order to access the gills, the operculum was lifted then cut, after the gill arches were visible and there was four on each side. Lastly, the head was removed in order to expose the brain of the fish by cutting the top of the head into a flap that is removed by using tweezers. The spleen, liver, gill