Does unilateral eyestalk ablation affect the quality of the larvae of the pink shrimp Farfantepenaeus brasiliensis (Letreille, 1817) (Decapoda: Dendrobranchiata: Penaeidae)?

Abstract

Unilateral eyestalk ablation has been widely used in commercial hatcheries of penaeid shrimps to accelerate female maturation, but has been associated with high broodstock mortalities and poor-quality offspring. We studied the reproductive performance and the quality of eggs and nauplii larvae of unilaterally ablated eyestalks and non-ablated Farfantepenaeus brasiliensis (Latreille, 1817) broodstock. The biochemical analysis of triglycerides, glucose, cholesterol, and total soluble protein was performed in the hepatopancreas, ovaries, hemolymph, eggs, and nauplii. We found that females with unilaterally ablated eyestalks showed a better reproductive performance but higher mortality than non-ablated females. The fertilization rate and the number of viable nauplii, however, were improved in non-ablated females. Eggs were smaller in the non-ablated than in ablated females, but the length of the nauplii was higher in non-ablated than in ablated females. The concentration of cholesterol and total soluble protein in hemolymph was higher in non-ablated than in ablated females. A higher concentration of total soluble protein, as well as the ratio of acylglycerides:cholesterol (AG:C), was found in the eggs of non-ablated females than in those of ablated females. The nauplii-condition index, calculated from the level of nauplii acylglycerides, percentage of viable nauplii, and length of nauplii, indicated that the index of offspring of the non-ablated broodstock was higher than in those of ablated females, which confirms that unilateral eyestalk ablation affects not only the mortality of females but the quality of the offspring as well.