The syphonophore, the Portuguese man of war:
This is a collection of jelly fish each having its own individual function, catching food, digestion, movement, reproduction.
I can understand that the digestive jelly fish can feed the other jelly fish but if only one of the jelly fish reproduce, then how do the other jelly fish in the colony come about?
Have I got the facts wrong, or does the reproducing jelly fish produce all of the jelly fish?
Helen - Wonderful creatures indeed! Although keep your distance, of course, because they are nasty stingers, but they're beautiful things to look at. I think this question is based on the fact that our listener knows that these animals are not in fact jellyfish. They're not single living creatures like that but they're colonies of lots of little creatures that live together. They belong in the same phylum, the Cnideria, as jellyfish and they look similar but they are in fact different. Portuguese man of wars are called siphonophores and they're made up of three main different types of little animals that live together. There are dactylozoids which make up the tentacles, there are gastrozoids which are the bits that eat the food, and there are gonozoids, and they are the bits of these creatures that reproduce. They produce sperm and they produce eggs. In fact, you get female and male Portuguese man of war, even though they’re called “Men”. The sperm will fertilize eggs in the water colum to produce larvae which grow into bigger Portuguese man of war. And the way that they grow from those individual cells is by asexual division of those cells and they produce all those individual three types of animals that live in this one colony and drift around the oceans, stinging things and eating things as they go.
Nazer, Mr D - (NAZ ) - Science asked the Naked Scientists: The syphonophore, the Portuguese man of war: This is a collection of jelly fish each having its own individual function, catching food, digestion, movement, reproduction. I can understand that the digestive jelly fish can feed the other jelly fish but if only one of the jelly fish reproduce, then how do the other jelly fish in the colony come about? Have I got the facts wrong, or does the reproducing jelly fish produce all of the jelly fish? What do you think? Nazer, Mr D - (NAZ ) - Science , Sat, 9th Jan 2010
Your post interested me so I searched for info. It seems you are right. I found that man o wars arent jelly fish at all (they just resemble them) and are in fact a colony of organisms-Siphonophora-each are so specialized that most lack the ability to survive on their own.They are considered on a border between a colony and a multicellular organism.The siphonophores, are an order of the Hydrozoa, a class of marine invertebrates belonging to the phylum Cnidaria. They are colonial, but the colonies can superficially resemble jellyfish; although they appear to be a single organism, each specimen is actually a colony of Siphonophora. The best known species is the dangerous Portuguese Man o' War (Physalia physalis).
surprised me too!
i just realized i misread your question. from what i read i was geting two different explanations of their reproduction process but i think what you wish to know is that after reproduction/fertilization, budding or miotic division takes place:
Nobody has answered the question, which I'll try to reformulate. The Man of War comprises four separate organisms (polyps): the sail and three zooids. Only one of these, the gonozooid, is responsible for reproduction. The gonozooid can presumably only reproduce more gonozooids, and not gastrozooids, because those are different organisms. So how exactly do more gastrozooids form? Also, how do all four polyps initially assemble to make a Man of War? Kevin, Mon, 1st Aug 2011
I got this off of the Waikiki Aquariums website:
There is a lot of confusion here, because physalias are very unique, and they are frequently mis-labeled as a colony of individuals. At best, they could be called a colony of zooids. These particular zooids, however, are not individuals in the robust sense of the word. The term colony here is often likened to a coral colony, but that connotes that it is a collection of asexually reproduced clones that can survive on its own if severed from the colony either artificially, or through natural, asexual, reproductive fission. As opposed to corals, physalias grow attached non-viable 'buds' that mature into specialized non-viable zooids.
At the risk of being over simplistic, indulge me an analogy.
How is the man of war a colonial organism if it all grows from the same original larva? On that basis humans would be colonies of their organs? Phil, Tue, 27th Sep 2016