High larval mortality and poor egg and juvenile quality are significant challenges in advancing pigfish (O. chrysoptera) production to the pilot scale. Despite progress in understanding reproductive biology in captivity, production protocols still require refinement. A deep understanding of developmental biology is crucial for identifying early developmental abnormalities, often linked to water quality, broodstock nutrition, and environmental or genetic factors. In this study, we characterized the embryonic development, endogenous reserve depletes and temperature effect during the egg incubation period.
During embryonic development, issues such as oil drop fragmentation were identified, serving as probable indirect stress indicators in broodstock handling procedures. The conditions of the broodstock strongly influence larval development from hatch to first feeding. Ensuring high-quality larvae at the first feeding stage is essential for achieving strong larval rearing survival rates, because the larval culture presents inherent challenges itself. The observed abnormalities during larval development, including the absence of gas bladder formation, retention of biliary secretions, and deformities, could be associated with nutritional deficiencies, mainly those that are related with LC-PUFAs, antioxidants, and carotenoids. These findings underscore the need for enhanced broodstock nutrition and handling procedures on pigfish aquaculture.
Additionally, our results emphasize the critical role of temperature in fish development, suggesting that aligning broodstock, incubation, and larval culture temperatures to mimic natural conditions can improve larval development to improve the quality at first feeding larvae stage.