Alberto Fontoura 1999

DISTRIBUIÇÃO E ESTRUTURA ETÁRIA DE Ocypode quadrata

95

DISTRIBUIÇÃO E ESTRUTURA ETÁRIA
DE Ocypode quadrata (FABRICIUS, 1787)
(CRUSTACEA, DECAPODA, OCYPODIDAE)
EM PRAIA ARENOSA DO LITORAL SUL DO BRASIL
ALBERTO, R. M. F.1 e FONTOURA, N. F.2
1

Museu de Ciências e Tecnologia (MCTPUCRS) (Prédio 40); 2Instituto de Biociências (Prédio 12)
Pontifícia Universidade Católica do Rio Grande do Sul/ PUCRS, Av. Ipiranga, 6681, C.P. 1429, CEP 90619-900,
Porto Alegre, RS, Brasil
Correspondência para: Regina Maria de Fraga Alberto, Museu de Ciências e Tecnologia (MCTPUCRS) (Prédio 40), Pontifícia
Universidade Católica do Rio Grande do Sul/ PUCRS, Av. Ipiranga, 6681, C.P. 1429, CEP 90619-900, Porto Alegre, RS, Brasil e-mail: [e-mail]
Recebido em 13/08/97 – Aceito em 17/08/98 – Distribuído em 23/02/99

(Com 11 figuras)
ABSTRACT
Age structure and spatial distribution of Ocypode quadrata (Fabricius, 1787) on a sandy beach from the south coast of brazil (Crustacea, Decapoda, Ocypodidae)
Spatial distribution and population structure of Ocypode quadrata (Fabricius, 1787) were studied at Pinhal beach, Rio Grande do Sul, from November/91 to December/93. Analysis of frequency distributions of the ghost crab population was based on indirect census, with burrow diameter measurement. It was identified the presence of two age-groups, with the possible presence of a third one. The maximal life span was estimated to be about 3 years. Burrow diameter/carapace width, lenght/width and weight/width relationships were estimated from samples obtained by excavating burrows and individual capture by traps. These relationship were ajusted by the following equations, respectively: DT = 0,6648 + 1,0013.L; C = 0,77.L1,02; and P = 0,0004.L3,0876 (DT is burrow diameter; C is the carapace lenght; L is the carapace width; and P is the weight). Spatial distribution analysis was performed based on distance and altitude to water line. These crabs dig burrows preferentialy in the central large range of