First Record of Gravid Female American Blue Crab (Callinectes sapidus Rathbun 1986) From the Black Sea

Mustafa Gül,Mehmet Aydin,Barış Bodur

doi:10.33714/masteb.795884

Abstract

The occurrence of American blue crab, Callinectes sapidus Rathbun 1896, has been reported from the Black Sea, however, no gravid female has previously observed. Here, we record the first gravid female blue crab from the Black Sea. One individual of Atlantic blue crab was caught at 2 m depth using trammel net on 24th June 2020. The carapace width, carapace length, and the wet body weight of the crab were 200 mm, 81.03 mm, and 406.22 g, respectively. We also counted the eggs and measured the egg size. We further determined that the majority of the eggs were eyed, suggesting potential adaptation of the blue crabs to the Black Sea ecosystem.

Highlights

Introductions of American blue crab have been reported from different localities on the coast of Europe including France, North Sea, Mediterranean Sea, Baltic Sea, Sea of Azov, and as well as Black Sea (Nehring, 2011)
Low water temperatures have been hypothesized to be the main causation for the unsuccessful establishment of the American blue crab in the Black Sea ecosystem (Nehring, 2011), since larval development and size at maturity are inversely related to the water temperatures (Hines et al, 2010) and no blue crab larvae can develop at water temperatures lower than 21°C (Hill et al, 1989)
This transformation in the Black Sea ecosystem has led to increase in water temperatures and the salinity, which overlaps with the increased number of records showing introduced species to the Black Sea including the American blue crab

Summary

Introduction

Introductions of American blue crab have been reported from different localities on the coast of Europe including France, North Sea, Mediterranean Sea, Baltic Sea, Sea of Azov, and as well as Black Sea (Nehring, 2011). The species has reached a notable density in the Mediterranean and Aegean Seas (Holthuis & Gottlieb, 1955; Williams, 1974; Castriota et al, 2012), its existence in the Black Sea has been rare (Bulgurkov, 1968; Shaverdashvili & Ninua, 1975; Monin, 1984; Zaitsev, 1998; Bashtannyy et al, 2002; Diripasko et al, 2009; Khvorov, 2010; Pashkov et al, 2012; Aydın, 2017) (Figure 1), suggesting a low adaptation ability of the species to the low temperature values of the Black Sea (Nehring, 2011) This hypothesis might further be supported by the recent increase in the number of reports showing existence of the blue crabs from the Black Sea as the water temperature increases in the Black Sea during the “Mediterranization” process (Micu & Todorova, 2009). Besides the reports showing the occurrence of the American blue crabs, no report has yet indicated reproductive capability of this species in the Black Sea including gravid females

Material and Methods

Results

Discussion

Conclusion