Biological characteristics of three Brachyuran crab species in the Lagoon of Elbibane, South-Eastern Tunisia
This study is a first contribution to the knowledge of the biology of three crab species, Carcinus aestuarii, Eriphia verrucosa and Pachygrapsus marmoratus, occurring in the intertidal zone of Elbibane lagoon, south-eastern Tunisia. A total of 1264 individuals from the three brachyuran species were collected monthly from April 2010 until March 2011 and their reproduction and growth parameters were determined. The seasonal distribution of carapace width showed for the three species that males have always a greater size than females. The length-weight relationship showed in the three species a negative allometry in males, and in non-ovigerous females. The von Bertalanffy growth model (VBGF) p…
Occurrence of the lessepsian species Portunus segnis (Crustacea: Decapoda) in the Gulf of Gabes (Tunisia): First record and new information on its biology and ecology
The alien blue swimming crab, Portunus segnis (Forskal, 1775), an Indo-Pacific species has been recorded in the Southern Mediterranean Sea since decades, even if its occurrence along the Tunisian coasts was not recorded yet. This paper reports the first record of P. segnis in the Gulf of Gabes, south-eastern Tunisia, with few observations on its biology and ecology. Twenty-four females of P. segnis were accidentally caught by local fishermen in October 2014 in shallow sandy areas covered mostly by seagrass and algal beds. Among these 24 individuals, 14 specimens (58.33%) were ovigerous. The mean carapace length (CL) and width (CW) of ovigerous females were 143.0 +/- 5.8 mm and 67.8 +/- 3.6 …