Tidal-amplitude rhythms of larval release: variable departure from presumed optimal timing among populations of the mottled shore crab

Autor(es)

Bueno, M. ^[1] ; Flores, A. A. V. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, BR-14040901 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Ctr Biol Marinha, BR-11600000 Sao Sebastiao, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Marine Biological Association of the United Kingdom; v. 90, n. 5, p. 859-865, AUG 2010.
• Citações Web of Science: 6

Resumo

It is widely assumed that optimal timing of larval release is of major importance to offspring survival, but the extent to which environmental factors entrain synchronous reproductive rhythms in natural populations is not well known. We sampled the broods of ovigerous females of the common shore crab Pachygrapsus transversus at both sheltered and exposed rocky shores interspersed along a so-km coastline, during four different periods, to better assess inter-population differences of larval release timing and to test for the effect of wave action. Shore-specific patterns were consistent through time. Maximum release fell within 1 day around syzygies on all shores, which matched dates of maximum tidal amplitude. Within this very narrow range, populations at exposed shores anticipated hatching compared to those at sheltered areas, possibly due to mechanical stimulation by wave action. Average departures from syzygial release ranged consistently among shores from 2.4 to 3.3 days, but in this case we found no evidence for the effect of wave exposure. Therefore, processes varying at the scale of a few kilometres affect the precision of semilunar timing and may produce differences in the survival of recently hatched larvae. Understanding the underlying mechanisms causing departures from presumed optimal release timing is thus important for a more comprehensive evaluation of reproductive success of invertebrate populations. (AU)

• Processo FAPESP: 01/11156-4 - Padrões espaço-temporais de produção e assentamento larval de caranguejos litorâneos (Crustacea, Brachyura) na costa norte do estado de São Paulo: subsídios para a elaboração de modelos da dinâmica de metapopulações
• Beneficiário: Augusto Alberto Valero Flores
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 06/58700-4 - Efeito da exposicao a acao das ondas no sincronismo semilunar da emissao de propagulos em invertebrados marinhos litoraneos da regiao de ubatuba, sp.
• Beneficiário: Marília Bueno Fernandes
• Modalidade de apoio: Bolsas no Brasil - Mestrado