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Email the author (Login required) Population structure of the burrowing crab Neohelice granulata (Brachyura, Varunidae) in a SW Atlantic salt marsh
DOI: https://doi.org/10.3856/vol43-issue3-fulltext-15
Abstract
Neohelice granulata inhabits estuarine and protected coastal areas in temperate regions, and is the most dominant decapod crustacean in the Bahía Blanca estuary. The population structure was studied during a year in a SW Atlantic salt marsh located in the Bahía Blanca estuary, Argentina. Crabs were sampled monthly from August 2010 to July 2011. The maximum observed density was 39 crabs/m2 in February and 70 burrows/m2 in May. The maximum carapace width (CW) in males was 32 mm and 27.5 mm in females. Medium size crabs were between 16 and 20 mm CW. Significantly smaller sized crabs were observed at the lower intertidal regions (p<0.05). The sex ratio was favourable for males and was significantly different from the expected 1:1 (p<0.05). The recruitment of unsexed juveniles crabs (CW<6.5 mm) was observed throughout the year and the presence of ovigerous females from October to February indicated seasonal reproduction. The average size of ovigerous females was CW= 20.8 mm and the smallest ovigerous female measured was 16 mm CW. For the fist time it has analyzed the population structure of the most important macroinvertebrate in a region of such importance as Bahía Blanca estuary. This study may help to make decisions in the area, where anthropic action is progressing day by day.
