Salinity preferences of the estuarine crab Chasmagnathus granula¬ta (Dana, 1851) after long term acclimation to different salini¬ties

CERVINO, C.O.; LUQUET, C.M.; HAUT, G.E.; RODRÍGUEZ, ENRIQUE M.

ATLANTICA

FURG

Año: 1996 vol. 18 p. 69 - 75

0102-1656

Males of the estuarine crab Chasmangnathus granulata were acclimated during 45 days to salinities of 7, 12, 20 and 34 ppt, and then submitted to a preference assay for these same salinities. Crabs acclimated to higher salinities (20 and 34 ppt) clearly preferred the highest salinity tested, whereas those acclimated to low salinities did not show any significant preference (p>0.05). These results are apparently related to the ion-regulating capacity developed during acclimation to differente salinities. Crabs aclimated to low salinities (which presumable developed strong hyper-regulatory mechanisms) would find no advantage in choosing a high, iso-ionic salinity, while the preference behavior of crabs acclimated to high salinities might be of adaptative value, especially in environments with important daily changes in salinity.