Reproductive physiology and reproductive control of two new/emerging species under rearing conditions, the meagre (Argyrosomus regius) and the greater amberjack (Seriola dumerili): physiological tools applied to aquaculture

Abstract

Overexploitation of marine resources is a major problem worldwide and threatens food security for humanity and many commercially important fish species are suffering from overexploitation (FAO, 2018). So, aquaculture is the only solution for the increase of seafood production, while at the same time aiding in the conservation of marine fish stocks, by reducing the fishing pressure from some species. In Brazil, marine aquaculture is still in its infancy and the control of reproductive aspects, such as, oocyte maturation (OM), ovulation, spermiation, spawning, fertilization and the production of high quality eggs are imperative for aquaculture development for any fish species. When reared in captivity, many fish species exhibit some problems in reproduction and females often fail to undergo OM and ovulation and males present problems related to sperm production and quality. Therefore, studies on maturation induction therapies using exogenous hormones and modulation of the environmental factors such as, temperature and salinity, the management of the broodstock, tank or cage size, to stimulate maturation are important tools to induce ovulation, spermiation and spawning of cultured broodstocks and for the production of high quality gametes. The studies proposed here aim to evaluate the effects of salinity and temperature manipulations on reproductive maturation, spawning success and egg/sperm quality in meagre, and investigate spawning kinetics, parental contribution of group spawning and develop a pair-spawning protocol for the induced reproduction of greater amberjack. So, these experiment will improve our knowledge on reproductive aspects for developing aquaculture sustainability using domesticated broodstocks which can provide a year-round seed production and afford selective breeding for the development of strains with required characteristics and finally, attend the aquaculture industry demand. The knowledge to be acquired is indispensable to boost aquaculture, which is an economic area with a great potential in Brazil.