Hello all,
Eric has located three articles that directly address research studies on Pocillopora reproduction. I have copies of the pdf and can email them to people who are interested. These pdfs are for reading only and should not be posted on any public or private webistes. It is perfectly acceptable to quote from the articles as long as you give the citation.
Here are the abstracts and citations:
C.D.H. Sherman , D.J. Ayre and K.J. Miller (2006).
Asexual reproduction does not produce clonal populations of the brooding coral Pocillopora damicornis on the Great Barrier
Reef, Australia
Coral Reefs Vol. 25, 7-18.
Abstract:
We have investigated the relationship between genotypic diversity, the mode of production of brooded larvae and disturbance in a range of reef habitats, in order to resolve the disparity between the reproductive mode and population structure reported for the brooding coral Pocillopora damicornis. Within 14 sites across six habitats, the ratio of the observed (G o) to the expected (G e) genotypic diversity ranged from 69 to 100% of that expected for random mating. At three other sites in two habitats the G o /G e ranged from 35 to 53%. Two of these sites were recently bleached, suggesting that asexual recruitment may be favoured after disturbance. Nevertheless, our data suggest that brooded larvae, from each of five habitats surveyed, were asexually produced. While clonal recruitment may be important in disturbed habitats, the lack of clonality detected, both in this and earlier surveys of 40 other sites, implies that a disturbance is normally insufficient to explain this species’ continued investment in clonal reproduction.
Article #2 Citation:
S. Harii, H. Kayanne, H. Takigawa, T. Hayashibara, M. Yamamoto (2002). Larval survivorship, competency periods and settlement of two brooding corals, Heliopora coerulea and Pocillopora damicornis.
Marine Biology, Vol. 141, 39-46.
Article #2 Abstract:
Larval dispersal and recruitment are important in determining adult coral distribution; however, few studies have been made of coral larval dispersal. This study examined the larval behavior, survivorship competency periods and settlement of two brooding corals, Heliopora coerulea and Pocillopora damicornis, in relation to different potential larval dispersal patterns. We also examined the lipid content of H. coerulea as a means of flotation and a source of energy. Planulae of H. coerulea were on average 3.7 mm in length, lacked
zooxanthellae, and were mostly benthic, probably because of restricted movement and low lipid content (54% by dry weight). Planulae of P. damicornis were on average 1.0 mm in length, had zooxanthellae and swam actively. The competency period of H. coerulea was shorter (30 days) than that of P. damicornis (100 days). Forty percent of H. coerulea planulae crawled onto the substrata within 1 h of release, and 47% settled within 6 h. By contrast, fewer than 10% of P. damicornis planulae crawled onto the substrata within the first hour and 25% settled within 6 h of release. The planulae of H. coerulea may have a narrower dispersal range than those of P. damicornis, settling and recruiting near parent colonies. Thus, brooding corals exhibit variations in larval dispersal patterns, which are characterized by their position in the water column and competency periods.
Article #3 Citation:
Kelley Whitaker (2006). Genetic evidence for mixed modes of reproduction in the coral
Pocillopora damicornis and its effect on population structure.
Marine Ecology Progress Series Vol. 306, 115-124.
Article #3 Abstract:
ABSTRACT: Allozyme electrophoresis of 6 polymorphic loci was used to estimate the relative importance of
sexual and asexual reproduction in Western Australian populations of the coral Pocillopora damicornis and to infer the extent of larval dispersal between them. Evidence for considerable yet variable amounts
of asexual reproduction was found. Only 96 of a total of 644 coral heads sampled were apparently of sexual origin, and 8 of the 10 populations showed large departures from Hardy-Weinberg equilibria as a result of both heterozygote excesses and deficits. Multi-locus genotypic diversity values were significantly less
than expected for 8 of the 10 populations sampled, but the magnitude of these values varied enormously (range Go:Ge = 0.072 to 0.770). Significant genetic subdivision among populations was found (FST = 0.360) that was not attributable to different reefs (FRT = 0.080), habitat type (FHT = –0.039), or geographical
distance between populations (Mantel test p = 0.129). However, pairwise comparisons revealed significant genetic subdivision at all spatial scales sampled. Furthermore, this subdivision was largely maintained even among populations of putative sexual origin (FST = 0.175). These results are consistent with the notion
that reefs at Ningaloo and the Houtman Abrolhos Islands are primarily self-seeding and that asexually derived recruits have a considerable effect on local abundance and population structure.
If you would like any of these articles, please PM or email me.
Thanks,
Brian
Linear Mode
