Starfish - Dissection

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PATRICIA's FINAL HOURS

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Patient #001880: Star, Patrica

Specimen: Starfish
Weight: 5.7 oz
Eye Color: N/A
Height: 4.5 in
Ethnicity: Marine Echinoderm

Biography: Starfish, you can see them in fish tanks, like in Nemo or even in Spongebob, like Patrick the Star. But more realistically you can find them in all the oceans around the world, primarily at the sea bottom. Though it looks like these things don't eat, they do. Their diet consists of clams, mussels, and barnacles. It seems that Starfish have some similar food choices when compared to Humans, however, they definitely do not breathe the same. Humans, you and I, use our mouths and nose to breathe in air which then travels to our lungs, and everywhere else in our body. Starfish use their feet. I can't even imagine what the world would be like if Humans respired from their feet. Anyway, the starfish's feet are composed of thin tissue that allows the diffusion of gases which allows the oxygen from the seawater to travel to all the tissues that compose of their body. They also use the raised bumps on their bodies to help with this process as well. Fun fact: These prickly textured surface is also used as protection from birds(I don't understand how they get into the water that deep), fish and other predators that expel all their anger on the poor starfish.

REFER TO THE INFORMATIONAL DISSECTION VIDEO AT THE BOTTOM IF KNOWING HOW TO DISSECT THIS ORGANISM IS DESIRED. THE VIDEO CONTAINS A DETAILED VISUAL AND VOICEOVER.

Dissection Instructions

First, place the starfish so that it is facing belly up. Next, cut about 1/4 of an inch of the tip of one of the legs off. Then, using a scalpel, cut a rectangle in the leg so that you make a flap revealing the inner components. In order to view the stomach and other internal organs, cut out a circle in the middle of the starfish, revealing the central disk. 

INFORMATIONAL DISSECTION VIDEO ABOVE

External Anatomy

Arms: help with movement and capture prey

Central Disk: most central part of starfish; where arms radiate from

Madreporite: site where water enters the water vascular system

Internal Anatomy

Gonads: produce the starfish's gametes (sperm or egg)

Stomach: where food is digested

Works Cited

http://visual.merriam-webster.com/animal-kingdom/simple-organisms-echinoderms/echinoderms/anatomy-starfish.php