Ragged Sea Hare (Bursatella leachii) |
 |
| Description Sea hares are our largest opisthobranchs and some species on our coast may reach eight inches in length. These are massive, soft bodied animals with a distinctly rabbit like appearance when viewed head on. They often have a pair of lateral, wing like swimming flaps, the parapodia, and the head bears two pairs of tentacles. One pair, the rhinophores, is located on top of the head just behind the eyes whereas the second pair is simply the elongated anterior margin of the head. The shell is small and flattened, and at least partly internal. Sea hares are herbivores that graze on seaweeds on rock jetties, pilings, creek bottoms, sea walls, and grass beds. They lay large, tangled masses of spaghettilike egg strings and some release clouds of dark ink when threatened. The ragged sea hare, Bursatella, is smaller than Aplysia brasiliana, the other common sea hare in our waters. It has numerous, long, branched, filamentous processes covering its body. It lacks the large winglike parapodia and has no shell as an adult. [Ref. Ruppert and Fox] Its distribution is world wide in warm temperate and tropical waters. Some authorities recognize seven or eight geographical subspecies, but all have a similar natural history. One peculiarity seems to be a tendency to have irregular population explosions where, after being nearly invisible for years, they can suddenly be found everywhere. It may be that they are well camouflaged and hard to find when their numbers are low, or it may be that they are actually absent. They have a planktonic larval stage so that animals can be recruited from some distance away, and when all conditions are optimal. The animals feed on a blue-green algal film that forms on sand grains and other surfaces in the shallow, warm water bays they favor. |
| Complete
classification tree Family = Notarchidae Order = Anaspidea Subclass = Opisthobranchia Class = Gastropoda Phylum = Mollusca |
| Local
habitat Found in the Intracoastal Waterway. In years when populations are high they are often seen on clam beds, presumably feeding on the algal mat adhering to the bags containing the growing clams. |
| Collection
method By hand in shallow water; by trawl in the deeper water of the ICW. |
| Links
and references http://www.seaslugforum.net/ Newsgroup dealing with things in the world of sea slugs. http://www.seaslugforum.net/bursleac.htm http://www.ciesm.org/atlas/Bursatellaleachi.html http://www.seafriends.org.nz/indepth/nd006.htm http://www.neurobio.upr.clu.edu/neuroethology/neuroethology-98/bursate.htm A new northern record for Bursatella leachii pleii Rang (Opisthobranchia), with notes on its biology. W. L. KRUCZYNSKI and H. J. PORTER, THE NAUTILUS, Volume 83, (1969–1970), 40–42 |
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