Question

Discuss the life cycle of the jellyfish Aurelia. Is there an Alternation of Generations in the life cycle? Explain.

Answer 1

Aurelia is referred to a genus of jellyfish called moon jellies. The life cycle consists of two stages namely, polyp and medusa. The medusa stage of the jelly fish exhibit sexual reproduction. The male jelly fish releases a string of sperms and which are ingested by the female jelly fishes. Further, the embryo of the jelly fish is developed into planula larva and the cilia of the larva helps it to implant to the floor of the sea where it grows into scyphistoma. This further develops to form a strobila which represents the mature form of a polyp. Different types of asexual reproduction will takes place after forming the strobila. The first type of asexual reproduction involves budding where a new organism is formed from the body of the parent and the organism formed is called ephyra. Second involves fission where the organism splits into two organisms. Other type of asexual reproduction involve fragmentation in this a part of the parent organism regenerates the portions which are missing and develop into a complete organism. The ephyra develops into mature medusa, the mature form of jelly fish. Then in the medusa stage the jelly fish releases gametes into the water and this cycle continues. The life cycle of  Aurelia exhibit alternation of generation. The alternate generation consists of two stages of reproduction, sexual and asexual. In Aurelia the medusa stage involve sexual reproduction and the polyp stage involves asexual reproduction. The following figure shows the life cycle of Aurelia.