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Caracterização do comportamento reprodutivo do cavalo-marinho de focinho comprido (Hippocampus guttulatus, Cuvier 1928)
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Abstract(s)
Os cavalos marinhos estão incluídos no género Hippocampus, o qual é um dos
muitos pertencentes á família Syngnathidae. Entre as diversas características que os
distinguem dos outros géneros, estes apresentam a particularidade de ser o macho que
desempenha os cuidados parentais, incluindo o período de gestação. Esta característica
tem levado regularmente a estudos acerca do comportamento reprodutivo de algumas
espécies pertencentes ao género, e do papel de cada um dos sexos na reprodução. Na
sequência de estudos anteriores foi desenvolvido uma experiência acerca do
comportamento reprodutivo do cavalo marinho de focinho comprido, Hippocampus
guttulatus, uma das duas espécies de cavalo marinho existentes na Ria Formosa. Numa
primeira fase, este estudo comportamental foi desenvolvido de forma a caracterizar o
comportamento de corte desta espécie, assim como os papéis desempenhados por cada
um dos sexos no processo reprodutivo. Seguidamente, foi feita a delimitação temporal
das várias etapas que constituem o ciclo reprodutivo desta espécie, analisou-se a sua
estratégia reprodutiva e o potencial reprodutivo de cada um dos sexos. O conhecimento
destes factores será uma ferramenta útil no desenvolvimento de um protocolo adequado
de cultivo e manutenção, em cativeiro. H. guttulatus apresenta papéis sexuais
convencionais, nos quais, são os machos que competem pelo acesso à parceira e
consequentemente, cabe às fêmeas a selecção do parceiro. Em situações onde a
proporção sexual de machos disponíveis é superior à de fêmeas, o período total de corte
tende a diminuir, por diminuição do tempo de inactividade entre cortes, pelo que a
competição induz um aceleramento no processo reprodutivo e, quer o período de corte,
como todas as outras etapas que constituem o ciclo reprodutivo desta espécie, parecem
estar condicionados pelas alterações da temperatura verificadas. O parto é um processo
descontínuo e o número máximo de descendentes atingido por gestação foi de 678
juvenis. Os intervalos de latência entre acasalamentos consecutivos apresentam uma
maior duração para os machos, pelo que, as fêmeas em situações onde não há limitação
de machos disponíveis tendem a acasalar com outro macho, antes da conclusão do
período de gestação do macho inicial. Desta forma, a espécie H. guttulatus não revelou
monogamia estrita para uma época reprodutiva, o que provocou uma desigualdade no
potencial reprodutivo de machos e fêmeas, ocorrendo uma prevalência das fêmeas em
relação aos machos no número total de descendentes produzidos por época reprodutiva.
Seahorses are included in the genus Hippocampus, which is one of many included in the family Syngnathidae. Among the several features that distinguish them from other genera, they have the distinction of being the male performs parental care, including the period of gestation. This feature has led to regular studies on the reproductive behavior of some species of the genus and about the role of each sex for reproduction. Following previous studies was conducted an experiment on the reproductive behavior of the long snouted seahorse, Hippocampus guttulatus, one of two species of seahorse existing in the Ria Formosa. At first this behavioral study was carried out to characterize the courtship behavior of this species as well as the roles played by each sex in the reproductive process. It was subsequently made time delimitation of the various steps that constitute the reproductive cycle of this specie; we analyzed its reproductive strategy and reproductive potential of each sex. The knowledge of these factors will be a useful tool in the development of a protocol suitable for the cultivation and maintenance in captivity. H. guttulatus has conventional sex roles, in which males are competing for access to the partner and therefore it is up to the selection of the female partner. In situations where the sex ratio of available males is higher than in females, the total courtship, tends to decrease by decreasing downtime between courtship behavior interactions, so that competition leads to an acceleration in the reproductive process and shortened the courtship, like all the other steps that constitute the reproductive cycle of this species seem to be driven by changes in temperature observed. The birth of juveniles is a batch process and the maximum number of juveniles by pregnancy was 678. The intervals of latency between consecutive matings have a longer duration for the males, so that the females in situations where there is no limitation of available males tend to mate with another male before the end of the gestation period of the initial male. Thus, the H. guttulatus revealed no strict monogamy to a reproductive season and has led to inequality in reproductive potential of males and females, occurring a prevalence of females compared to males in the total number of offspring produced by reproductive season.
Seahorses are included in the genus Hippocampus, which is one of many included in the family Syngnathidae. Among the several features that distinguish them from other genera, they have the distinction of being the male performs parental care, including the period of gestation. This feature has led to regular studies on the reproductive behavior of some species of the genus and about the role of each sex for reproduction. Following previous studies was conducted an experiment on the reproductive behavior of the long snouted seahorse, Hippocampus guttulatus, one of two species of seahorse existing in the Ria Formosa. At first this behavioral study was carried out to characterize the courtship behavior of this species as well as the roles played by each sex in the reproductive process. It was subsequently made time delimitation of the various steps that constitute the reproductive cycle of this specie; we analyzed its reproductive strategy and reproductive potential of each sex. The knowledge of these factors will be a useful tool in the development of a protocol suitable for the cultivation and maintenance in captivity. H. guttulatus has conventional sex roles, in which males are competing for access to the partner and therefore it is up to the selection of the female partner. In situations where the sex ratio of available males is higher than in females, the total courtship, tends to decrease by decreasing downtime between courtship behavior interactions, so that competition leads to an acceleration in the reproductive process and shortened the courtship, like all the other steps that constitute the reproductive cycle of this species seem to be driven by changes in temperature observed. The birth of juveniles is a batch process and the maximum number of juveniles by pregnancy was 678. The intervals of latency between consecutive matings have a longer duration for the males, so that the females in situations where there is no limitation of available males tend to mate with another male before the end of the gestation period of the initial male. Thus, the H. guttulatus revealed no strict monogamy to a reproductive season and has led to inequality in reproductive potential of males and females, occurring a prevalence of females compared to males in the total number of offspring produced by reproductive season.
Description
Dissertação de Mestrado, Biologia Marinha, Especialização em Pescas e Aquacultura, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2009
Keywords
Cavalo marinho Hippocampus guttulatus Ria Formosa Reprodução