Population ecology of the blue crab Callinectes danae (Crustacea: Portunidae) in a Brazilian tropical estuary

Abstract

This paper aims at describing the population ecology of the swimming crab Callinectes danae Smith, 1869 in one of the most productive estuaries of Brazil, the Santa Cruz Channel. These crabs were monthly collected from January to December/2009 at four stations along the channel, two in the upper and two in the lower estuary. A total of 2373 specimens of C. danae were collected during the study. Males had a larger average carapace width than non-ovigerous females (60.0 ± 15.6 mm and 52.9 ± 12.4 mm, respectively), an adaptation that gives greater protection for females during the copulation. Overall sex ratio did not differ significantly from 1:1. However, evaluating sex-ratio by sampling area, males and juveniles of both sexes occurred preferentially in the upper estuary (p < 0.05), while adult females, including ovigerous, inhabited the lower estuary, an area of major marine influence (p < 0.05). While juveniles look for estuarine waters due to the benefit from the shelter and abundance of food, ovigerous females migrate to areas of greater depth and higher salinity in order to provide a more favorable environment for embryonic and larval development and to enhance larval dispersal. Recruitment of juveniles was continuous along the year, but intensified from March to June and, with less intensity, from October to December

The influence of environmental factors on the abundance of swimming crabs (Brachyura, Portunidae) in a tropical estuary, northeastern Brazil

“…Meanwhile, these values are around 24°C, which is still below the lowest temperature recorded here. Araújo et al (2011) analysing the same population studied here, noticed a highest catches of juvenile females with increasing of temperature. Carvalho & Couto (2011) reported that the abundance of C. danae decreases in salinities higher than 33 g/1.…”

Parí­¢metros populacionais e distribuição de Arenaeus cribrarius (Crustacea, Portunoidea), no litoral sudeste brasileiro

“…The lack of size difference between sexes of A. cribrarius also differs from most results reported for other portunids, including this species (PINHEIRO and PARDAL-SOUZA, 2016). Generally, several studies on portunids indicate that in larger size classes the males have a clear predominance over females (MANTELATTO and FRANSOZO, 1999b;BRANCO and FRACASSO 2004;RIPOLI et al, 2007;PEREIRA et al, 2009;ARAÚJO et al, 2012). The reason for that is because males invest more energy in their somatic growth than females do, who in turn direct it towards reproduction (HARTNOLL, 1982), since the production of oocytes requires more energy than the production of spermatozoa (HARTNOLL, 2006).…”

Diet and population biology of the invasive crabCharybdis helleriiin southwestern Atlantic waters

“…In Portunidae, sexual dimorphism with males larger than females is common (Williams 1974;Pinheiro & Fransozo 1999;Araújo et al 2012). This pattern was observed for C. hellerii both in the present study and in other populations (Morán & Atencio 2006;Sant'Anna et al 2012b).…”