Relative growth of Petrochirus diogenes (Linnaeus, 1758) (Crustacea, Anomura, Diogenidae) in the Ubatuba region, São Paulo, Brazil

Abstract

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 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.

Comparative analysis of populational structure of the Hermit Crab Dardanus insignis (Anomura: Diogenidae) in a Subtropical Area of the Brazilian Coast

“…Similar results were found by Bertini & Fransozo (2000) for Petrochirus diogenes (Linnaeus, 1758); Bertini et al (2004) for Loxopagurus loxochelis (Moreira, 1901) and by Fernandes-Goés et al (2005) for D. insignis in the Ubatuba region. This ratio, according to Wenner (1972) is an anomalous pattern, commonly verified for marine adult crustaceans.…”

“…In Brazil, the last decades have been marked by a reasonable number of studies on hermit crabs and anomuran communities (Negreiros-Fransozo & Nakagaki, 1998;Turra & Leite, 2000;Fransozo et al, 1998;2008;Mantelatto & Garcia, 2002) and particular features of each species such as population structure, reproduction, relative growth and shell occupation (Negreiros-Fransozo et al, 1992;Reigada & Santos, 1997;Bertini & Fransozo, 1999a;Garcia & Mantelatto, 2001;Turra et al, 2002;Frameschi et al, 2013). Recent studies have described some features of D. insignis, including the post-embryonic development (Hebling & Mansur, 1995), population dynamics Fernandez-Goés et al, 2005) and fecundity (Miranda et al, 2006).…”

Análise comparativa da estrutura populacional do ermitão endêmico do Atlântico Ocidental Loxopagurus loxochelis (Decapoda, Anomura) em duas regiões do estado de São Paulo, Brasil

“…Também há registros de ciclos descontínuos: e.g. Calcinus tibicen e Petrochirus diogenes (BERTINI & FRANSOZO, 2000), também com pico reprodutivo no verão. Esta variabilidade no perfil reprodutivo é indicativa de uma ampla plasticidade da espécie em adaptar-se às condições ambientais e à coexistência com outras espécies, evitando competição e conseqüente perda de benefícios para os envolvidos, particularmente em L. loxochelis, que apresenta preferência por águas frias e tem o litoral paulista como real limite norte de distribuição e ocorrência em abundância (MARTINELLI et al, 2002).…”

Population structure and breeding period of Pachycheles monilifer (Dana) (Anomura, Porcellanidae) inhabiting sabellariid sand reefs from the littoral coast of São Paulo State, Brazil

“…HAZLEIT 1966;ASAKURA 1995;FRANSOZO & MANTELATTO 1998;BERTINI & FRANSOZO 1999). ABRAMS (1988) assumed two possible advantages for males being larger than females.…”