Sea nettle: Encyclopedia II - Sea nettle - Life cycle and reproduction

Sea nettle - Life cycle and reproduction

The nettle passes though two different body forms during its life cycle. The most familiar form is the medusa, while the smaller form is the larval stage. Jellyfish are either male or female. A few steps are required in order for a jellyfish to reproduce. First, the reproductive organs in the male (the gonads) develop in the lining of the gut. Second, the male releases sperm through its mouth column. Third, the sperm has to swim into the mouth of the female, which will fertilize the eggs that she has inside.

After that, early embryotic development begins either inside the female jellyfish or in brood pouches along the oral arms. Next, small, swimming larvae (planula) leave the mouth or brood pouches and enter the water column. Soon after, the larvae seek shade and attach to the bottom of the water, forming polyps. The polyps then divide and bud into young jellyfish (ephyra). In a few weeks, an ephyra will grow into an adult medusa, completing its complex life cycle. The jellyfish will live for three to six months if nothing happens to them.

Adapted from the Wikipedia article "Life cycle and reproduction", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki