SRA

Penaeid aquaculture has the highest total production out of all crustaceans, though is hindered by the need for eye stalk ablation (ESX) to induce spawning in captive bred animals, shortening the broodstock productivity significantly. This study aimed to investigate the effectiveness of known ovarian maturation stimulatory factors in a commercial setting, compared to ESX. An injection trial was performed in mature domesticated P. monodon females using either double stranded gonad inhibiting hormone (dsGIH), the combination of serotonin (5-HT) and spiperone, or the combination of dsGIH, methyl farnesoate, hydroxyprogesterone, red pigment concentration hormone and lamprey gonadotropin releasing hormone-1. ESX was more effective in promoting vitellogenesis and inducing spawning in P. monodon than all other experimental groups; the dsGIH group was the second most effective. The trial highlighted further knowledge of vitellogenesis is needed to develop an effective alternate to ESX. To address this gap, we performed both RNA-Seq and metabolomic analysis, comparing previtellogenic and vitellogenic females. We found that dopamine, its precursor phenylalanine and its derivative epinephrine, are 5 times higher in concentration in the hemolymph of vitellogenic females compared with previtellogenic females. RNA-Seq analysis highlighted that the dopaminergic system plays a key role in the early stages of ovarian maturation, showing clear differential expression in the dopamine biosynthesis and tyrosine catabolism pathways, dopamine transporter and two dopamine receptors. Manipulation of the dopaminergic system should therefore be explored as an alternative technique to ESX in inducing ovarian maturation of P. monodon.