Comparison of the effect of red light exposure and eyestalk ablation for inducing sexual maturation and improving egg quality in the cleaner shrimp Lysmata amboinensis

Abstract

Female cleaner shrimps Lysmata amboinensis either underwent eyestalk ablations (EA), or were treated with two different wavelength intensities of red light (peak at 630 nm), and then their sex maturation and the effects on their egg quality parameters were compared. Vitellogenesis-inhibiting hormone (VIH), vitellogenin (VTG), VTG-receptor (VTG-R), and crustacean hyperglycemic hormone (CHH) expressions in the hepatopancreas were analysed. VTG-R expression (in situ) levels that caused the EA and red irradiation to induce the synthesis of VTG-R were assessed, and the triglycerides (TG) and glucose levels in the eggs were analysed. VIH expression was decreased in all experimental groups, but VTG and VTG-R expressions were increased. CHH expression and TG and glucose concentrations were higher in the red irradiation group, compared to the EA group. These results confirmed that the red light not only had a positive effect on the promotion of sex maturation, but it also improved the quality of the eggs, when compared to the EA method.