Effects of bilateral eyestalk ablation on gonadal maturity, moulting and biochemical changes in the hemolymph of female Potamonpersicum crabs (Decapoda, Brachyura, Potamidae)

Abstract

Adult female crabs (Potamonpersicum; n=65) were collected from the Jajrood River in the east of Tehran, Iran. Both eyestalks were removed in crabs that weighed 27.6 ± 2.1 g. Changes in the levels of glucose and protein titers in the hemolymph, the number of hemocytes, gonadal and hepatic indices, body weight and carapace length were determined. The level of glucose in the hemolymph was significantly decreased at the end of the first week following eyestalk ablation and significantly increased by the end of the second and third weeks following eyestalk removal compared to the control groups with intact eyestalk (p < 0.05). A significant increase was observed in the total protein level of the hemolymph of destalked crabs at the end of the third week compared to those in the control group (p < 0.05). The fractions of total protein showed significant changes at the end of the third week compared to the control group (p < 0.05). The mean total hemocytes count (THC) in the hemolymph was significantly increased in ablated crabs at the end of the second and third weeks compared to the control group (p < 0.05). The gonadal and hepatic indices of the ablated crabs were significantly increased and decreased, respectively, at the end of the second week compared to the control groups (p < 0.05). The mean body weight of the ablated crabs was increased significantly at the end of the second and fourth weeks compared to the control group (p < 0.05). No significant change was observed in the mean carapace length of the ablated crabs at the end of the second week, but it had increased significantly by the end of the fourth week compared to the control group (p < 0.05). The ablated crabs moulted four weeks after the removal of their eyestalks, but no precocious moulting was observed in the control group.