MEPS 289:307-310 (2005)  -  doi:10.3354/meps289307

Pre-planular external development in the brooding coral Agaricia humilis

Dirk Petersen1,2,*, Godfried W. N. M. Van Moorsel3

1Rotterdam Zoo, PO Box 532, 3000 AM Rotterdam, The Netherlands
2University of Duisburg-Essen, Institute of Ecology, Department of Hydrobiology, 45117 Essen, Germany
3Ecosub, PO Box 126, 3940 AC Doorn, The Netherlands

ABSTRACT: In September 2003, translocation of the scleractinian coral Agaricia humilis on the reef of Curaçao, Netherlands Antilles, was followed by a prodigious release of small floating premature larvae by all colonies (n = 19). Release occurred mainly during the first 3 d after sampling and peaked with 8.02 ± 7.60 (mean ± SD) embryos cm–2 d–1 on Day 2. These propagules developed externally into planulae and reached settlement competency about 3 d after release. During the whole 8 d monitoring period, the colonies also released normal planula larvae (0.27 ± 0.39 cm–2), which were able to settle without delay. We assume that premature release occurred as a result of stress connected with the sampling method applied. The obligatory development of at least 3 d has important consequences for dispersal. This is one of the first reports of successful external development of embryos into planulae in a coral species, known as a brooder, and demonstrates yet another possible mode of reproduction in scleractinian corals.

KEY WORDS: Brooder · Embryogenesis · Reproduction · Dispersal · Life history · Planula · Coral

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