The Atlantic crab Callinectes sapidus was recently recorded in Tunisia and presents an invasive behavior. This study aims to evaluate its socio-economic impacts on small-scale fisheries and to analyze variations in chemical composition, fatty acids profile, and nutritive value according to sex and edible tissues. Socio-economic surveys via face-to-face revealed a decline in fishermen’s income from 15% to even 70% (damages on fishing nets and catches). Muscles yield of Callinectes sapidus ranged between 36.07±2.84% and 42.83±6.53% respectively for females and males. All the analyzed tissues contained high protein contents (> 23%) and particularly cephalothorax muscles reaching 27.05±0.16%. This new exotic food can be recommended in low fat diets since it contained less than 5% of total fats. The fatty acid profile was dominated by the polyunsaturated fatty acids (PUFA) for both sexes and all the analyzed tissues. Eicosapentaenoic acid, docosahexaenoic acid and arachidonic acid were the most abundant PUFA in all tissues ranging respectively from 9.31% to 15.64%, from 8.74% to 13.78% and between 6.81% and 9.21%. All the nutritional indexes of lipids indicated that this crab could be beneficial for human health. In addition, it constitutes a new marine resource with high economic opportunity.

Reproduction is a key feature in the dynamics and establishment of non-indigenous species in new areas. Thus, reproductive biology studies are particularly important for predicting whether alien species can become invasive and to pinpoint the most effective time to implement management options and mitigation actions. Here, we report the reproductive aspects of the invasive crab Libinia dubia from the central Mediterranean Sea. The population was sampled monthly for two years (January 2015 to December 2016) on the southern Tunisian coasts (Gulf of Gabès). A total of 4469 specimens were examined, of which 50.88% were males and 49.12% were females (Confidence Interval, CI = 0.015). The overall sex ratio was slightly male-biased (1: 0.97). The first gonadal sexual maturity was earlier in females than in males. Fecundity increased with crab size and weight. Libinia dubia has a single annual spawning season (March to July) in the study area. Species reproductive activity was greatest in spring, with a peak in May, while the sexual rest phase occurred during October and November in females and from September to November in males. Reproduction is one of the most influential factors in the ability of invasive species to successfully thrive and establish a population in a new environment. Our results provide important biological inputs for improving the understanding of L. dubia reproductive performance and support recommendations for research relevant to the prediction of future L. dubia invasions.