Genetic differentiation among populations of the brooding soft coral ...

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Jul 3, 2002 - Genetic differentiation among populations of the brooding soft coral. Clavularia koellikeri on the Great Barrier Reef. Received: 20 December ...
Coral Reefs (2002) 21: 233–241 DOI 10.1007/s00338-002-0236-7

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C. Bastidas Æ J.A.H. Benzie Æ K.E. Fabricius

Genetic differentiation among populations of the brooding soft coral Clavularia koellikeri on the Great Barrier Reef

Received: 20 December 2001 / Accepted: 29 March 2002 / Published online: 3 July 2002  Springer-Verlag 2002

Abstract The contribution of sexual and asexual reproduction, the spatial patterns of genetic structure, and the potential gene flow among populations were determined for the soft coral Clavularia koellikeri (Octocorallia: Alcyonacea, Clavulariidae) at ten sites among six reefs from two well-separated regions of the Great Barrier Reef (GBR), Australia. Eight allozyme loci indicated that colonies of C. koellikeri separated ‡3 m were produced sexually. Genetic diversity was lower in the southern (18S) compared with the northern (10S) populations, suggesting that reefs closer to the southernmost limit of the distribution of C. koellikeri within the GBR (19S) may represent a more marginal habitat for this species. High levels of genetic differentiation were significant at all spatial scales (sites within reefs, reefs, and regions) from