• Question: How do jellyfish reproduce?

    Asked by to Thon, Catherine, James, Natalie, Shaylon on 16 Jun 2014. This question was also asked by .
    • Photo: Natalie Pilakouta

      Natalie Pilakouta answered on 16 Jun 2014:

      Great question! Jellyfish can reproduce either sexually or asexually. Sexual reproduction happens in the adult stage. Males release sperm and females release eggs into the water and when the sperm and eggs combine, they produce small larvae called planula. These larvae attach on rocks and stay there to grow until they become adults.

      During this larval stage, they can also reproduce asexually, which means that they produce clones of themselves without needing to be fertilized by another jellyfish. This happens through the creation of “polyps” which are much like branches growing on the side of a tree. But unlike tree branches, each of these polyps detaches from the original organism that they came from and later grow to become the adult form of jellyfish that we are most familiar with.

    • Photo: James Bell

      James Bell answered on 16 Jun 2014:

      Adult jellyfish release clouds of sperm and eggs into the sea around them. The sperm and eggs combine to make a baby jellyfish (a larvae called a planula). The planula settles onto a rock or something else hard as a kind of upside-down jellyfish called a polyp and after a while, little jellyfish bud off of the polyp and go back to live in the water.

    • Photo: Catherine Offord

      Catherine Offord answered on 16 Jun 2014:

      Not much to add to that great answer, except that when jellyfish reproduce sexually, they often gather together in huge swarms. These swarms can cover over a hundred miles of coastline! It has become such a problem in some countries that fishing companies sometimes use special robots to detect and remove jellyfish to avoid them getting trapped in nets or clogging up machinery. (See this article for more info on the ‘jellyfish shredder’ http://www.telegraph.co.uk/news/newstopics/howaboutthat/10349839/Jellyfish-shredding-robot-tested-to-control-swarms.html)

    • Photo: Anthony Caravaggi

      Anthony Caravaggi answered on 17 Jun 2014:

      There’s nothing I can add to those excellent answers. 🙂

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