Oxidative stress in the subantarctic false king crab Paralomis granulosa during air exposure and subsequent re-submersion

Abstract

In the Southern South America, the stone or false king crab Paralomis granulosa constitutes the main crab fishery. One of the extremely stressful situations to fished crustaceans is the air-exposure handling once they are on deck. The aims of this study were to determine effects of air-exposure and re-submersion on: (1) the antioxidant enzyme activities and lipid peroxidation in different tissues; and (2) changes in the meat palatability in Paralomis granulosa. One hundred and twenty male crabs were captured in Beagle Channel (54°S, 68°W) and randomly assigned to the two planned experiments. For the air-exposure, four groups of 8 animals each were exposed to dryness at 7 °C for 6 h, and then re-submerged for 0.5, 1, 2 and 24 h respectively, whereas a fifth group was used as control. Activities of superoxide dismutase (SOD), catalase (CAT), glutathione-s-transferase (GST), as well as lipid peroxidation were measured in gills, muscle, hepatopancreas and haemolymph. Almost all tissues showed a significant increase of antioxidant enzyme activities until 2 h of recovery (α = 0.05). The highest antioxidant enzyme activities were found in gills, in which SOD, CAT and GST activities were similar to the control values after 24 h of recovery. Moreover, gills and hepatopancreas showed significantly increased (α = 0.05) lipid peroxidation at 0.5 h of re-submersion. For the palatability assay, three groups of twenty crabs each were air-exposed at 7 °C for: 6, 12 and 18 h and then re-submersed for 24 h, whereas a fourth group was used as control. Four dishes of ~ 10 g meat each were offered to 30 judges who performed a taste ranking with the meat samples. Even if differences in the meat flavor of P. granulosa were detected, participants could not rank samples according to the increasing air exposure of animals. Live transportation of P. granulosa is promising and crabs can be re-submerged and offered alive.