Spatial variability in reproductive cycle of the gorgonians Paramuricea clavata and Eunicella singularis (Anthozoa, Octocorallia) in the Western Mediterranean Sea
Paramuricea clavata (Risso, 1826) and Eunicella singularis (Esper, 1794) are the most representative gorgonian species in hard bottoms sublittoral communities in the Western Mediterranean Sea. Reproductive cycles of two populations of both species were studied in two distinct locations approximately 600 km apart (Medes Islands and Cape of Palos), in order to assess interpopulation variability on a relevant geographic scale. Seasonal variation of lipid concentration levels in the gorgonian tissue was used as a tool to quantify energy storage by each studied population in order to explain possible interpopulation differences in gonadal output. Sex ratio in Medes Islands populations of both species was 1:1, while in Cape of Palos sex ratio was significantly male biased (1:7) in P. clavata, and female biased (1.7:1) in E. singularis populations. Spawning timing occurred in all cases coinciding with a marked increase in sea-water temperature in spring, and after the most successful feeding season, but comparing localities there was a clear temporal shift in the time of gametes release, appearing well linked to the shift in sea-water temperature rising in spring in both sites at the depth where populations are placed. Therefore, in this study the temperature appears as the main synchronizing factor of gonadal development within these populations. Significant differences in gonadal volume per polyp were found in both species owing mainly to differences in the number of gonads per polyp between populations, with Cape of Palos populations displaying higher values in both studied species, suggesting that the exposition to different local conditions may be reverted in a different gonadal output. But the observed patterns in lipid concentrations levels in gorgonians disable us to conclude that lipid concentration levels explain the observed differences in gonadal output found in this study.
KeywordsCoral Species Female Gonad Gamete Release Female Coloni Male Coloni
The authors thank S. Rodergas, L. Pierboni, I. Fiorillo, and C. Saleta for their help with the laboratory analyses, and J.C. Calvín Calvo for his help with the field work. We are grateful to J. Pascual for sea-water temperature data and to C. Orejas and G. Carpaneto for their useful comments improving the first version of the manuscript. Funding for this study was provided by Spain’s Ministry of Education and Science through the MEDGORG project REN2000-0633-C03-01/MAR and CTM2004-03120/MAR.
- Alino PM, Coll JC (1989) Observations of the synchronized mass spawning and postsettlement activity of octocorals in the Great Barrier Reef, Australia: biological aspects. Bull Mar Sci 45:697–707Google Scholar
- Giese AC, Pearse JS (1974) Introduction: general principles. In: Giese AC, Pearse JD (eds) Reproduction of marine invertebrate. Academic Press, New York, pp 1–49Google Scholar
- Harrison PL, Wallace CC (1990) Reproduction, dispersal and recruitment of scleractinian corals, Chapter 7. In: Dubinsky Z (ed) Ecosystems of the world, vol 25. Coral Reefs Elsevier, Amsterdam, pp 133–207Google Scholar
- Kojis BL, Quinn NJ (1981) Aspects of sexual reproduction and larval development in the shallow water hermatypic coral, Goniastrea australensis (Edwards and Haime, 1857). Bull Mar Sci 31:558–573Google Scholar
- Ribes M, Coma R, Rossi S, Micheli M (2006) The cycle of gonadal development of Eunicella singularis (Cnidaria: Octocorallia): trends on sexual reproduction in Mediterranean gorgonians. Invertebr Biol (in press)Google Scholar
- Sokal RR, Rohlf FJ (1995) Biometry, 3rd edn. Freeman and Company, New YorkGoogle Scholar
- Soong K (1991) Sexual reproductive patterns of shallow-water reef corals in Panama. Bull Mar Sci 49:832–846Google Scholar
- Stimson JS (1987) Location, quantity and rate of change in quantity of lipids in tissue of Hawaiian hermatypic corals. Bull Mar Sci 41:889–904Google Scholar
- True (1970) Étude quantitative de quatre peuplements sciaphiles sur substrat rocheux dans la région marseillaise. Bull Inst Océanogr Monaco 69(1401):1–48Google Scholar
- Weinberg S (1979) Autoecology of shallow-water octocorallia from Mediterranean rocky substrata. I. The Banyuls area. Bijdr Dierk 49:1–15Google Scholar
- Weinberg S, Weinberg F (1979) The life cycle of a gorgonian: Eunicella singularis (Esper, 1794). Bijdr Dierk 48:127–140Google Scholar