Showing papers on "Holothuria published in 1997"

Specificity of sperm chemotaxis among great barrier reef shallow-water holothurians and ophiuroids

Abstract: Sperm chemotaxis and sperm motility activation by egg or ovarian extracts were demonstrated in 24 holothurians (six genera from three families) and 22 ophiuroids (eight genera from five families) from the Australian Great Barrier Reef. Specificity was observed mainly at the family level in holothurians, but a single case of specificity at the species level was found in the genus Bohadschia. No recognizable specificity was found between any of the currently recognized subgeneric groups within the genus Holothuria. A similar pattern of specificity was previously observed in a group of dendrochiridotid holothurians in temperate waters. In contrast to the holothurians, specificity in ophiuroids existed mainly at the genus or species level. The best case of specificity at the species level was among six species in the genus Macrophiothrix which were reciprocally tested and a further three species in the same genus which were partially tested. Examples of partial specificity at the species level were also found in the general Ophiarthrum and Ophiocoma. The sperm chemotaxis assay reliably sorted to species a random collection of unidentified Macrophiothrix ophiuroids. These results suggest that sperm chemotaxis may play a role in gamete recognition prior to fertilization in one group of echinoderms. J. Exp. Zool. 279:189-200, 1997. © 1997 Wiley-Liss, Inc.