Dictionary » M » Medusa

Medusa

Definition

noun, plural: medusae

(zoology) The freely-swimming, umbrella- or disk-shaped gelatinous form of Cnidarians (as opposed to the polyp form)


Supplement

Cnidarians exhibit two body forms: the freely swimming medusa and the sessile polyp forms. The medusa appears like an umbrella (others are disk in shape) with trailing tentacles on the lower surface (compare polyp). Also, it reproduces sexually in contrast with polyp reproducing asexually. Scyphozoans are group of Cnidarians that solely exhibit medusa forms. Other Cnidarians such as hydrozoans have both polyp and medusa stages in their life cycle.


Word origin: from its likeness to the tentacled head of Medusa in Greek mythology

Synonym(s):

Compare:

Related term(s):


Please contribute to this project, if you have more information about this term feel free to edit this page



Results from our forum


Re: Anyone knows what organism is this?

Nice photos. The second one is definitely a coelenterate of some kind. Perhaps the medusa stage of one.

See entire post
by skeptic
Tue Jun 21, 2011 1:06 am
 
Forum: Microbiology
Topic: Anyone knows what organism is this?
Replies: 2
Views: 1259

Anyone knows what organism is this?

... Oh, and perhaps this one too? I have no idea! Sea-spider maybe not, so I assume this is also a microscopic perhaps medusa of some sort? Or plankton?

See entire post
by Alekas
Sun Jun 19, 2011 5:49 pm
 
Forum: Microbiology
Topic: Anyone knows what organism is this?
Replies: 2
Views: 1259

Re: animal with the longest lifespan

... animal but natures only error was that made this immortal being so small hehe : Turritopsis nutricula or immortal jellyfish is a hydrozoan whose medusa, or jellyfish, form can revert to the polyp stage after becoming sexually mature. It is the only known case of a metazoan capable of reverting ...

See entire post
by master94
Mon Jul 12, 2010 12:25 pm
 
Forum: Zoology Discussion
Topic: animal with the longest lifespan
Replies: 9
Views: 12588

Re: Why Cnidaria swim?

There are many different forms of cnidaria, ranging from sessile corals to mobile jellyfish. The main reason for their mobile forms (including the medusa stage of anthozoans) is dispersal. Sometimes they swim towards the light for other reasons. There is a jellyfish living in a lake in Palau that ...

See entire post
by skeptic
Wed Mar 24, 2010 8:41 pm
 
Forum: Zoology Discussion
Topic: Why Cnidaria swim?
Replies: 4
Views: 3226

Why Cnidaria swim?

... swimming stadium among Cnidaria (and also swamps) ? I think the answear is that becouse of a polyp- colony is single- sexual, they have to produse medusa, if they want to get some kind of gentic variation. Am i getting this right, or can somone point me in the right direction? :D Thanks!

See entire post
by ManBearPig89
Wed Mar 24, 2010 2:47 pm
 
Forum: Zoology Discussion
Topic: Why Cnidaria swim?
Replies: 4
Views: 3226
View all matching forum results

This page was last modified 11:00, 27 September 2013. This page has been accessed 10,765 times. 
What links here | Related changes | Permanent link