Chemical aspects of mass spawning in corals. II. (-)-Epi-thunbergol, the sperm attractant in the eggs of the soft coral Lobophytum crassum (Cnidaria: Octocorallia)

Autor: RH Willis, Porfirio M. Aliño, Bruce F. Bowden, Z. Florian, Gabriele M. König, R. de Nys, R. L. Miller, John C. Coll, Priscila de Almeida Leone, Anthony R. Carroll, Margaret N. Clayton, Philip Alderslade, Russell C. Babcock, M. Maida, A. Heaton
Rok vydání: 1995
Předmět:
Zdroj: Marine Biology. 123:137-143
ISSN: 1432-1793
0025-3162
Popis: The eggs of Lobophytum crassum Von Marenzeller, 1886, collected at Magnetic Island (19°10′S; 146°52′E) in October or November between 1983 and 1993, contained significant amounts (6% dry weight) of (-)-epi-thunbergol, in addition to other terpenoid metabolites also present in the parent colony. (-)-Epi-thunbergol was not present in the tissues of the releasing colony. Using fluorocarbon droplets impregnated with the chemotactic molecules and a videomicroscopic technique for the direct observation of sperm under the influence of attractant molecules, we showed that (-)-epi-thunbergol, whether isolated from L. crassum or from a gorgonian octocoral (Briareum sp.), significantly attracts sperm from L. crassum colonies. Attraction could be detected using direct observation at concentrations as low as 3.25 μg ml-1. This is the first evidence for sperm chemotaxis in the Alcyonacea. Eggs from L compactum, a common alcyonacean coral at Orpheus Island (18°36′S; 146°29′E) contained (-)-thunbergol as the egg-specific compound. L. compactum was not found at Magnetic Island. (-)-Thunbergol from L. compactum and (+)-thunbergol from a Douglas fir tree both showed levels of attraction similar to (-)-epi-thunbergol against L. crassum sperm. Although L. crassum sperm were apparently neither stereo- nor enantio-specific in their selectivity for chemotactic molecules, (-)-epi-thunbergol was identified as the natural sperm attractant in the eggs of L. crassum.
Databáze: OpenAIRE
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