Effect of air exposure in the gills of the subantarctic stone crab Paralomis granulosa in the Beagle Channel, Argentina

ROMERO M.C.,; ANSALDO M.,; LOVRICH G.A.

La Paz, Baja California, México

Workshop; Second Workshop on Comparative Aspects of Oxidative Stress.; 2005

In Tierra del Fuego, the fishery for Paralomis granulosa represents one of the most important artisan fisheries. After their capture, animals are kept in baskets and exposed to dryness for several hours. In such condition, the flux of water running through the gills is interrupted producing a local ischaemic process. As a consequence a concomitant increase of reactive oxygen species begins, triggering oxidative stress. The aim of this study was to determine variations of antioxidant enzymes in gills of male crabs at different times of air exposure. Fifty crabs >82 mm of carapace length were captured in the Beagle Channel (54º 50´S, 68º 20´W) during winter 2004 (air-water temperatures: 2-6ºC). Animals were transported to the laboratory and kept for one week in individual tanks with running sea water at 6ºC. Five groups of 10 crabs each were exposed to dryness at different times (0, 3, 6, 12 and 24 h). Crabs were placed in individual plastic boxes without water and with cloths embedded in seawater to maintain the air-humidity. Boxes were at 8ºC. After dry exposition, crabs were dissected, their 7th gills were removed, and immediately frozen at -20ºC. The activity of the antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione S transferase (GsT), and protein oxidation were measured. Gill CAT and GsT activity changed significantly (p<0.05) with time. The maximum activity observed was at 6 h of exposition. Afterward the activity of these enzymes decreased. Gill SOD activity only decreased at 3 h, and kept constant values subsequently. Protein oxidation showed a similar pattern of CAT and GST enzymes. The critical time of air exposition was probably between 6 and 12 h. Thereafter animals could not be able to induce the synthesis of antioxidant enzymes or proteins. Supported by CONICET, ANPCyT, and DNA.