Carbonic anhydrase activity in gills and other tissues of the estuarine crab, Chasmagnathus granulata (Decapoda, Brachyura, Grapsidae)

MONSERRAT, J.M.; VITALE, A.M.; RODRÍGUEZ, ENRIQUE M.

NAUPLIUS

Sociedade Brasileira de Carcinología

Año: 1997 vol. 5 p. 23 - 31

0104-6497

Activity of the carbonic anhydrase (CA) enzyme was studied in adult males crabs of the species Chasmagnathus granulata. CA activity was measured in different gills (3 to 8), hepatopancreas, muscle (claw) and hypodermis of crabs acclimated to 12 ppt salinity. The enzymatic activity was significantly (p<0.05) higer in posterior gills (6 to 8) than in anterior ones (3 to 5). The CA activity was not significantly different (p>0.05) among muscle, hypodermis and hepatopancreas, being their enzymatic activities lowe than CA activity of posterior gills. In a second experiment, crabs were acclimated to 20 ppt salinity during 10 days, and the submitted to as 2.5 ppt salinity. The time course of AC activiation in the posterior gills (6 to 8) was then determined at 0, 7, 24, 96, and 168 h after transference to the low salinity. CA activity at 7, 96 and 168 h was significantly (p<0.05) higher than the activity recorded at the beginning of the experiment. These results suggest the existence of both a short and long term acclimation rsponse in C. granulata during ionie hyper-regulation, similar to the activation profile of Na+,K+-ATPase exhibited by several crustacean species.