Impact of unilateral eyestalk ablation on Callinectes arcuatus (Ordway, 1863) under laboratory conditions: behavioral evaluation

Abstract

Eyestalk ablation allows the removal of neurohormones that inhibit early reproduction and decreases the time to complete the molting cycle. The present study evaluated the impact of unilateral eyestalk ablation on the behavior of blue crab breeders Callinectes arcuatus in the short term under laboratory conditions. Immature male and female crabs and individuals in the intermolt stage were collected in Ohuira Bay, Ahome, Sinaloa, Mexico. Three bioassays were performed: males, females, and male-females each with three treatments; control + xylocaine (50 μL, 5%), squash ablation + xylocaine (50 μL, 5%), ablation by string ligation + xylocaine (50 μL, 5%), each with three replicas and three periods of evaluation after the ablation procedure (10 min, 2 h, and 24 h). Kruskal-Wallis and Chi-square (χ2) tests were used to evaluate significances (P < 0.05) in the behavior of C. arcuatus. The sizes of blue crab C. arcuatus were 9.72 ± 1.0 cm of carapace width. The feeding behavior of the male-females bioassay was significant at 2 h (P < 0.05). The results obtained were satisfactory using two techniques, unilateral eyestalk ablation by squash and ligation in which pain and aggressiveness indicators were mitigated. Disorientation and aggressiveness in males were significant at 2 h (P < 0.05), and in females after 10 min, and 2 h after ablation (P < 0.05). In the male-females bioassay, aggressiveness was significant at 2 h (P < 0.05). Courtship and copulation were recorded in those crabs subjected to unilateral eyestalk squash ablation (13 and 8, respectively).