[Cnidaria] Can anyone i.d this jelly?

[jgarfield at ucsd.edu]

Hi Marc,
Here's more info about your great hydrozoan find from  
www.marinebiodiversity.ca
These midwater jellies have also been documented in Monterey Bay, California.

Enjoy!
Judith


Ptychogena lactea A. Agassiz, 1865
 Classification :
Phylum : Cnidaria
Class : Hydrozoa
Order : Hydroida
Family : Laodiceidae

Synonyms : no synonyms found
Common name : no common name found

 Biology :
Dimensions : umbrella up to 90 mm wide, 30 mm high
Reproduction : Sometimes a colony will have reproductive polyps, called
gonozooids, which produce medusoids (tiny jellyfish-like animals).
However, reproduction within a colony often occurs asexually by budding
off new polyps from the main stem.
Diet : Primarly carnivorous which prey on sea urchins, gastropods,
bivalves, or crustaceans that crawl or swim into their grasp.
Predators : Generally, cnidarians' nematocysts are a remarkable weapon in
deterring animals far more `advanced’ than themselves. However, some other
taxa have succeeded in `recycling’ nematocysts by preying upon cnidarians
and incorporating the nematocysts into their own armoury (e.g. certain
species of nudibranchs and turbellarians).


 Ecology :
Range : Passamaquoddy Bay; St. Lawrence estuary
Habitat : Due to the alteration of generations in hydrozoas, the habitat
varies between the asexual benthic colonial polyps (sessile) and the
sexual planktonic medusae.
Occurrence : occurrence in the Bay of Fundy not noted
Importance (environmental, commercial, conservation, educational,
scientific, social) : not noted
Conservation Status : no status at present


 Additional information :
Hydrozoan polyps are connected to each other via the gastrovascular cavity
(almost like a continuous stomach), with the colony exhibiting
polymorphism. This means that there are different kinds of polyps within
the colony, each specialized for a certain function. For example, a
feeding polyp is known as a gastrozooid. These gastrozooids capture and
ingest food (small plankton) using their many tentacles, and share this
food with the other members of the colony through the continuous
gastrovascular cavity. There are also defensive polyps, called
dactylozooids, which have stinging cells used to defend the colony from
predators.


 References :
Calder, Dale, 2003; Linkletter, L.E., 1977; Shih, C.T., 1977

 ARC collection :
Representative in collection (cat no.) : Yes (8650098, 8650099, 8650100)
Locality : St. Andrews


 ITIS information :
ITIS no : 50513
Species reviewed by ITIS : No


 Related Links :
http://www.itis.usda.gov/
http://www.ucihs.uci.edu/biochem/steele/default.html
http://www.teaching-biomed.man.ac.uk/bs1999/bs146/biodiversity/cnidaria.htm
http://jellieszone.com/




> Hello Everyone,
>
> I need some help with identifying this jelly. It was found in shallow
> water
> in Escoumins, Gulf of St. Lawrence, Canada in September.
> Diameter of the bell is 2"- 2.5"
>
> Any ideas? Thank you very much for your help.
>
> Best wishes,
> Marc Carrel
> Halifax
> _______________________________________________
> List-Info: https://maillists.uci.edu/mailman/listinfo/cnidaria
>