Population biology of Excirolana armata (Dana, 1853) (Isopoda, Cirolanidae) on an exposed sandy beach in Southeastern Brazil

Autor(es)

Petracco, Marcelo ^[1] ; Cardoso, Ricardo S. ^[2] ; Corbisier, Thais N. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Depto Oceanog Biol, Inst Oceanog, BR-05508120 Sao Paulo - Brazil

^[2] Univ Fed Estado Rio de Janeiro, Depto Ecol & Recursos Marinhos, Inst Biociencias, Rio De Janeiro - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MARINE ECOLOGY-AN EVOLUTIONARY PERSPECTIVE; v. 31, n. 2, p. 330-340, JUN 2010.
• Citações Web of Science: 13

Resumo

The reproductive biology and population dynamics of the cirolanid isopod Excirolana armata (Dana, 1853) were analysed through monthly samples from December 2003 to November 2005 on Una beach, Sao Paulo state (24 degrees S), in Southeastern Brazil. Sampling was performed along three transects established from the base of foredunes to the waterline. On Una beach, E. armata showed continuous reproduction with higher abundances of ovigerous females in winter and spring (July-November) with a higher peak of juveniles in spring (November 2004). The fecundity ranged from 2 to 18 eggs/embryos per female, depending on the female length. The incubation period was estimated as 2 months. The life span of males and females was nearly 1 year. The short life span and the high energetic expenditure inherent to reproduction with maternal care, probably kept females from producing more than one brood in their lifetime. When comparing the population of E. armata on Una beach (24 degrees S) with populations in Southern Brazil (32 degrees S), Uruguay (34 degrees S) and Argentina (36 degrees S), it was verified that several biological population traits (length of the smallest juvenile, length of the largest individual, length of the smallest and largest ovigerous females, range of fecundity and life span) tended to increase at higher latitudes, whereas other traits (instantaneous rate of mortality and the curvature parameter of von Bertalanffy growth function) tended to decrease. However, comparing E. armata on Una beach (24 degrees S) with a population situated at a close latitude (25 degrees S), unexpected differences in relation to population structure and to growth demonstrated and reinforced the importance of density-dependent factors over life history traits of E. armata on dissipative beaches. (AU)

• Processo FAPESP: 03/07089-5 - Produção secundária de carcinofauna e malacofauna macrobentônicas da zona entre-marés da Praia do Una, litoral Sul do estado de São Paulo
• Beneficiário: Thais Navajas Corbisier
• Modalidade de apoio: Auxílio à Pesquisa - Regular