Relative growth of Petrochirus diogenes (Linnaeus, 1758) (Crustacea, Anomura, Diogenidae) in the Ubatuba region, São Paulo, Brazil
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Data
1999-11-01
Autores
Bertini, Giovana [UNESP]
Fransozo, Adilson [UNESP]
Título da Revista
ISSN da Revista
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Editor
Instituto Internacional de Ecologia
Resumo
O presente trabalho tem por objetivo investigar o crescimento relativo e a heteroquelia de Petrochirus diogenes. Os indivíduos foram coletados com um barco de pesca comercial, equipado com duas redes do tipo double-rig, durante o período de 1993 a 1996, na região de Ubatuba, SP. Os indivíduos foram pesados e mensurados na região do escudo cefalotorácico e dos própodos quelares. Os dados foram plotados em função do comprimento do escudo e ajustados na equação y = a.x b. Foram obtidos 479 exemplares (307 machos e 172 fêmeas). Nas relações do escudo, obteve-se um crescimento isométrico para ambos os sexos. As relações do quelípodo direito mostraram diferentes padrões de crescimento, enquanto o esquerdo apresentou uma alometria positiva para ambos os sexos. Para os ermitões, as mudanças em relação as partes ou apêndices não são tão visíveis como nos braquiúros, impossibilitando a detecção das alterações alométricas com precisão. Na análise da heteroquelia, observou-se que P. diogenes apresenta o quelípodo direito maior em ambos os sexos, no entanto, os machos atingem tamanhos superiores. A presença de heteroquelia pode beneficiar o ermitão durante as interações agonísticas e nos comportamentos pré-copulatórios.
The purpose of this paper is to investigate the relative growth and heterochely in the hermit crab Petrochirus diogenes. Hermit crabs were collected in the Ubatuba region, SP, from 1993 to 1996; using a commercial fishing boat equipped with two double-rig nets. Body mass of each individual was weighed and their cephalothoracic shield and chelar propodus size were measured. Body mass and chelar propodus size were regarded as dependent variables and plotted against length of cephalothoracic shield according to the allometric equation y = a.x b. A total of 479 individuals were obtained being 307 males and 172 females. Cephalothoracic shield width follows an isometric growth for both sexes. Otherwise, right cheliped dimensions show different relative growth patterns and left cheliped ones present a positive allometry in males and females. Unlike brachyurans, ontogenetic changes in the growth rate of chelar propodus are not clearly discernible, which prevents the accurate detection of allometric variations. In both sexes, the right cheliped is larger than the right one. Cheliped size is a sexual dimorphic feature with males bearing larger chelipeds than females. Heterochely may be particularly adaptive in agonistic interactions and precopulatory behaviour in P. diogenes.
The purpose of this paper is to investigate the relative growth and heterochely in the hermit crab Petrochirus diogenes. Hermit crabs were collected in the Ubatuba region, SP, from 1993 to 1996; using a commercial fishing boat equipped with two double-rig nets. Body mass of each individual was weighed and their cephalothoracic shield and chelar propodus size were measured. Body mass and chelar propodus size were regarded as dependent variables and plotted against length of cephalothoracic shield according to the allometric equation y = a.x b. A total of 479 individuals were obtained being 307 males and 172 females. Cephalothoracic shield width follows an isometric growth for both sexes. Otherwise, right cheliped dimensions show different relative growth patterns and left cheliped ones present a positive allometry in males and females. Unlike brachyurans, ontogenetic changes in the growth rate of chelar propodus are not clearly discernible, which prevents the accurate detection of allometric variations. In both sexes, the right cheliped is larger than the right one. Cheliped size is a sexual dimorphic feature with males bearing larger chelipeds than females. Heterochely may be particularly adaptive in agonistic interactions and precopulatory behaviour in P. diogenes.
Descrição
Palavras-chave
crescimento relativo, ermitão, Petrochirus, Diogenidae, relative growth, hermit crab, Petrochirus, Diogenidae
Como citar
Revista Brasileira de Biologia. Instituto Internacional de Ecologia, v. 59, n. 4, p. 617-625, 1999.