Survival rate and restricted growth of marbled crab (Pachygrapsus marmoratus) in different salinity levels

The semi-terrestrial marbled crab (Pachygrapsus marmoratus Fabricius, 1787) is one of the most common species in the intertidal belt of rocky shores of the Mediterranean Sea. This study aimed to understand survival and restricted growth of marbled crab in different salinity levels (0, 5, 15, 25, 35‰) and dry area (D). Crabs were collected from rocky shores by hand in ？zmir in January 2018. Specimens (initial mean weights of 0.82±0.01 g and n=180) were randomly distributed to 10-L aquariums with three replicates and they were not fed during the experiment. Results indicated that the survival times of crabs showed significant differences in salinity levels (P<0.001). All the individuals in the dry area and 0‰ salinity level died within the first 2 months. For the other salinity levels, all specific growth rate values decreased at minus on 84th day. Forty percent of crabs in aquariums that represented 15‰ salinity level were survived until the 126th day and the experiment was ended in the 140th day when the mortality of the last crab (0.73 g) occurred. In conclusion, the optimal salinity level for the survival and restricted growth of P. marmoratus was determined as 15‰ and 25‰, respectively. Future surveys would need to investigate the effects of different food types on survival and growth of this potential ornamental crab species of marine aquariums