Digging Inside the Perch
Perch Dissection - Mitcham-PAPBio-2 - Irina Didenko
Background Information
The perch belongs to the kingdom Animalia, phylum Chordata and has a scientific name of Perca. It lives in small ponds, lakes, streams and rivers. Its predators are large fish, birds, turtles, and bears. The things the perch feeds on are insects and small fish. It is a fish with a large eyes for easy predation, and specific skin and skeleton for other animals to be hard to catch it.
Where Does the Perch Stand?
Fish (and Perch) were one of the first creatures to evolve because they are in the water. This is a primitive diagram yet we can see that once it possesses jaws and is one of the oldest creatures in this diagram with an ancestor of a hagfish.
Obvious Objectives
We, the students, dissect the perch to become familiar with the internal and external anatomy of a fish. It also gives the opportunity to observe the placement of organs and their relationship to one another.
Dissection
Do fish breathe?
My lab group cut around the flap called the operculum which is a layer covering the gills to uncover them. We discovered 4 layers of gills which look like feathery structures.
Getting Inside
We made a square cut on the body part of the fish. We made a cut on the ventral side from the anus to the gills and around to make a square. This allowed us to access all of the internal organs.
Anatomy Diagram
This diagram highlights the internal organs and external parts that are important in a perch including the different types of fins.
Bony Fish (Perch) Anatomy
The Endocrine System
The endocrine system of the perch is fairly developed. The organs which it contains are the kidney, the liver, and the stomach. The liver is rather large and is just in front of the stomach. It is in charge of digesting food by secreting enzymes. It also stores fats and carbohydrates. The kidneys are found right behind the spinal column on the top of the fish. They are very small and their main function is to get rid of nitrogenous waste. It also regulates salt concentrations in the body allowing the fish to live in freshwater or salt water.
PERCH ARE IN THE NEWS!!!
FUN FACTS!!!
- The perch possesses 1 claudal fin (rear fin used for speed), 2 pectoral fins (on the sides by the gills used for turning and stopping), 1 anal fin (by the anus on the ventral side for stabilizing), 1 pelvic fin (anterior on ventral side for going up and down), and 2 dorsal fins (dorsal side and very hard, assists in turns).
- Perch does not have any eye lids
- The perch's heart contains an atrium for receiving unoxygenated blood and a ventricle which pumps blood to the gills and rest of body.
- This fish contains a swim bladder which is filled with air and allows the fish to maintain its depth without floating or sinking (buoyancy).
Links Used
- "Perch." Wikipedia. Wikimedia Foundation, 04 Aug. 2014. Web. 09 Apr. 2014. <http://en.wikipedia.org/wiki/Perch>.
- "Evidence for Endocrine Disruption in Perch (Perca Fluviatilis) and Roach (Rutilus Rutilus) in a Remote Swedish Lake in the Vicinity of a Public Refuse Dump." National Center for Biotechnology Information. U.S. National Library of Medicine, n.d. Web. 10 Apr. 2014. <http://www.ncbi.nlm.nih.gov/pubmed/11446832>.
- Weitzman, Stanley H. "Endocrine Glands." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 10 Apr. 2014. <http://www.britannica.com/EBchecked/topic/208456/fish/63640/Endocrine-glands>.
- http://www.iowas.co.uk/fish%20anatomy.html