Quote:
Originally Posted by Randy Holmes-Farley
Gigantea is not known to reproduce asexually.
It is reported to do so in the wild:
Incorporating fine-scale seascape composition in an assessment of habitat quality for the giant sea anemone Stichodactyla gigantea in a coral reef shore zone
http://www.springerlink.com/content/...3/fulltext.pdf
from it:
"At the end of the study, 43 anemones existed: nine had disappeared, six had been newly found, and one actinia had divided into three small individuals."
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In the link, they reference, Fautin and Allan 1992, to support their statement that gigantea reproduce sexually and asexually. Fautin and Allen 1992 does not support such a statement. Here's a link if you would like to check it out for yourself.
http://www.nhm.ku.edu/inverts/ebooks/intro.html
I also received this e-mail from Dr. Fautin on the subject.
"To prevent taking animals from the wild, some well-intentioned people propose cutting sea anemones in pieces to propagate them artificially. I am astonished how often I receive such proposals! It appears that only (or nearly only) anemones that naturally divide will predictably survive this treatment. Despite a persistent belief otherwise, anemones of most species do not reproduce asexually: only two of the 10 species that are natural hosts to anemonefishes do, and that may be a pretty good estimate of the prevalence of that ability among all anemones - 20% of species.
Perhaps the myth that division is how anemones reproduce is due in part to the feeling that anemones are "primitive" and division is a "primitive" attribute (in fact, anemones have been on earth far longer than humans, so can be argued to be more evolved!), and in part because pests such as *Aiptasia* are many peoples' ideas of a "typical" anemone. In fact, they are so prevalent and common precisely because they have that unusual ability - most of the 1000 or so species of anemones are less conspicuous because they do not occur in such densities at least in part because they lack that ability.
Another possible source of the misconception about anemone division is the practice of fragging corals. Clearly anemones and scleractinian corals are closely related. But that does not mean they can be treated identically. All anemones are solitary (even those that divide separate entirely once they have formed separate bodies, whereas polyps of corals in a colony remain physically attached to one another after they have arisen asexually). So fragging is dividing colonies (groups of polyps) into smaller colonies (fewer polyps per piece). By contrast, cutting an anemone into pieces is analogous to cutting you into two or more pieces; and for anemones of most species, the result would be precisely the same -- we would not have numerous identical yous, we would have no you.
Associated with an ability in some anemones to divide (into two or many pieces, depending on the species) is an ability to heal; obviously healing is necessary for regeneration. And although the reverse is not necessarily the case, it seems that animals that do not normally divide also have poor healing ability. So the prospects are dim for propagating anemones of species that do not naturally divide by cutting them into two or more pieces. One person who wrote to me rather triumphantly with a proposal to reduce collection from nature by cutting anemones in pieces as a means of artificial propagation was so pleased because he had cut in half two anemones of a species that does not reproduce asexually (as I recall, it was a species of *Stichodactyla*), and although both halves of one had died, both of the other had survived. So he started with two and ended with two, each half as large as the originals. I failed to see promise in this approach.
And even for the two species of anemonefish host anemones that seem to divide in nature, differences from place to place make me think there may be more than one species of what we think is a single species of each or there may be differences among individuals. Thus, even an anemone that is thought to be able to propagate asexually (*Entacmaea quadricolor*, the bubble-tip, and *Heteractis magnifica*, the "Ritteri" anemone) may die from being cut up.
Daphne Fautin
Daphne G. Fautin
Professor, Ecology and Evolutionary Biology
Curator, Natural History Museum and Biodiversity Research Center
Haworth Hall
University of Kansas"