Population structure, growth and reproduction characteristics of the portunid crab, Carcinus aestuarii Nardo, 1847 (Decapoda, Carcinidae) in Çardak Lagoon, Turkish Straits System

Abstract The aim of the present study was to determine the population structure and bioecological characteristics of the portunid crab, Carcinus aestuarii in Çardak Lagoon. In this study, the crabs were sampled by means of fyke-nets at 6 different stations between April 2015 and March 2016. A total of 2458 individuals (686 females, 1755 males, and 17 juveniles) were captured. The average carapace length was measured as 38.85 ± 0.17 mm in females, and 47.65 ± 0.16 mm in males. The highest number of specimens was observed in November with 239 individuals, while the lowest number (125 specimens) was observed in February. The reproductive period in both sexes was between November and February and females with eggs were found in November, February and March. An average number of eggs in a female was 61 390 ± 8.48 and the egg diameter was 345 μm. The female : male ratio was 0.39 : 1. This paper includes the first published data on population structure, growth, and reproduction characteristics of C. aestuarii in a protected lagoon in the Turkish Straits System.