Saturday, February 20, 2016

Jellyfish Reproduction

What do jellyfish eat?

The jellyfish is one of the most mesmerizing creatures of the marine land. They have a fascinating aspect to their life cycle, which is their process of reproduction. The process of reproduction in a jellyfish involves a number of different stages and the jellyfish passes through a number of different forms before it develops into the easily recognizable adult form in the last stage of the reproduction cycle. On the other hand, the different stages of reproduction in a jellyfish involve both the sexual and the asexual from of reproduction. Let's look at the reproduction cycle of the jellyfish to understand this fascinating process. 


Fertilization

jellyfish do not have any specialized bodily system for reproduction. The male jellyfish releases its sperm in the water. The female carries her eggs in her mouth or stomach. When the sperm that are released in the water come in contact with the female's eggs, they get fertilized. In the embryonic stage, these fertilized eggs are stored in brooding pouches along the oral arms of the female or in her stomach. 

Planula Larvae


After the embryonic stage is over, the larvae get transformed into tiny planulae that are free swimming and they detach themselves from their mother's body. At this stage, the jellyfish looks an oval shape and has tiny hair along its body that act like multiple oars to facilitate movement. However, these are not very effective, and the planulae float for a few days in the tides and currents of the water. At this stage, they start sinking towards the deep end of the ocean until they attach themselves to a hard surface and the next stage in their reproduction cycle begins. 

Polyps


Once the planula has found a hard surface, it attaches itself to it at its base. On the other end of the planula is its mouth which is surrounded by a few tentacles which help in procuring food and transport it to the planula's mouth. At this stage, this planula becomes a polyp and begins the most sessile stage of its life. It remains attached to the surface, and over time a new polyp gets formed from the trunk of the first polyp. This process is repeated innumerable times, until an entire colony of polyps is formed. The polyps of this colony are all connected to each other with small feeding tubes. This ensures that every polyp receives adequate nutrition irrespective of its place in the colony. This stage of jellyfish reproduction can last for years and the polyp colony can grow up to a tremendous size. 


Ephyra


When conditions are right, this colony of polyps begins to transform itself. Horizontal grooves appear on the outside of the colony. The topmost groove, which matures the fastest, then detaches itself from the colony and becomes a free swimming tiny jellyfish known as ephyra. 

Medusa


This is the last stage of the jellyfish reproduction cycle and the most recognized. The ephyra stage gives to the medusa stage where the tiny jellyfish grows into an adult and has a fully formed body and its distinct shape. Source

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