Population structure of the invasive Atlantic blue crab, Callinectes sapidus on the Eastern Adriatic coast (Croatia, Montenegro)

The Atlantic blue crab, Callinectes sapidus, is a highly invasive species that poses a signifi cant threat to Mediterranean ecosystems. In the last two decades, it has become established in several marine and estuarine areas of the eastern Adriatic Sea, resulting in a decline in commercial catches and damage to fi shing gear. This article reviews the current status of blue crab invasion in Montenegro and Croatia and analyses its abundance and population structure. Overall 619 crabs were sampled (male:female ratio, 1:1.91). Both carapace width and weight diff ered signifi cantly between males and females, with males having a wider carapace and more weight. There was a significant difference in carapace width and weight among sites. For the total population, the mean male and female carapace width was 130.3 & PLUSMN; 30.8 and 108.8 & PLUSMN; 41.4 mm, respectively. In addition, the mean male and female weight was 187.2 & PLUSMN; 85.6 and 132.5 & PLUSMN; 39.1 g, respectively. Coefficient b between the weight and carapace width of blue crabs was signifi cant at all locations, although it varied between males and females. This work will also document the impacts of the blue crab invasion on local ecosystems and provide comprehensive overview of populations structures and shed light on this important aspect of blue crab ecology.