Physiology Assignment Essay
I chose to look up a diagram on a sea dwelling organism known as a Jellyfish. Jellyfish have many different forms and are often characterized in different groups. One jellyfish that stood out to me was the Aurelia or also known as the Moon Jellyfish, which is like the basic jellyfish that I’ve always seen in pictures and books growing up. Jellyfish are said to be very effective predators, as one point in the time they were considered to be at the top of food chain. Being effective predators makes them physically fit to be in any environment that they travel to. Even though most would say that jellyfish are horrible swimmers, they are actually in fact many are very strong precise swimmers. Jellyfish can swim horizontally and vertically by using contraction against their bell to expel jets of water to propel them. One drawback of them not being stronger swimmers like larger fish is that they often get caught in sea currents and get stuck in them as they go pass.
The bell that propels them has a thick ring of strong muscle, called the coronal muscle. That muscle generates most of the power and energy used by a jellyfish. Now hanging from their subumbrellar is a projection called the manubrim which has the mouth its terminus. The mouth is often surrounded by oral arms normally just for but can sometimes be a multiple of four such as eight, depending on the type of species. Jellyfish don’t have a brain but they do bear a sophisticated computer which tends to all its needs and functions throughout the jellyfishes body. Though not as complex as a normal brain, it does suit the jellyfish well. Now on the edge of the underside of the jellyfish’s bell are its tentacles. The tentacles too can range in different numbers and sometimes some have thousands. These tentacles can be used to feed it, but also are use as it self defense mechanism to protect and also to hunt. The body and tentacles of a jellyfish can discharge stinging cells called nematocysts.
These stingers are grouped into stinging batteries. Their triggered by the touch of a potential prey or that of a predator looking to attack it. When attacking a prey they discharge dozen of harpoons into the victim thus, injecting venom to kill them. Other time it can discharge stick threads that can trap prey. There are many different type of nematocyst that can be found within the coelenterates, it all depends on the species. Having defenses like are good in the different types of way the jellyfish hunts and protects itself. Other jellyfish like the Lions Mane have vast tangle of tentacles that can sweep ocean floors like fishing nets. Their tentacle span is that of tennis court making it a very vicious hunter that can kill and capture dozens of prey. Needless to say jellyfish are often underestimated, but they pretty much can adapt to various conditions based off of their body’s structure. I wouldn’t want to be a fish being around a jellyfish that’s for sure.