Early Development and Metabolism

摘要: This chapter reviews the ontogeny and physiology of larval development in Sparidae family provides a comparative view biology species, highlighting those aspects that are relevant for their culture. Despite extensive similarities biology, phenotype, species-specific differences exist, partly related to different temperature optima among species. Sparids typically release large number small eggs hatch an early stage development. Larvae very vulnerable during requiring relatively strict biotic abiotic conditions survive grow. spawn buoyant pelagic containing single oil globule. Fertilized take only few days hatch. Decreased hatching, increased mortality, abnormalities occur outside optimal ranges. Newly hatched larvae small, have yolk sac, start feeding within 3–5 days. The ontogenetic events focus on organs structures necessary growth survival, including sensory organs, mouth, trunk tail muscle mass, digestive system. young poor visual acuity improves as eye diameter increases, new photoreceptors appear. Skeletal ossification been well studied, part because malformations issue cultured fish. pattern anatomical changes structural differentiation is functionality, behavior, environmental preferences. system gut, gall bladder, liver, pancreas, gastric glands develops rapidly. enzymes responsible digestion proteins, lipids, carbohydrates present at first feeding. functional tract pancreatic enzyme activity patterns similar described other fish groups. Growth influenced by many exogenous factors with food being most important. Other key culture include oxygen, salinity, turbidity, light. Optimal requirements change ontogeny. from longitudinally elongated body shape compressed form often characterized skull jaws. grow quickly critical initial swim bladder inflation usually occurs soon after complete absorption. transient physostome inflate bladders gulping air water surface. Factors influencing temperature, turbulence, light, genetics, egg quality, tank hydrodynamics. There considerable research Sparid nutrition. Highly unsaturated fatty acids (n-3 HUFA) essential good survival. Amino (AA) major energy source life stages. supply dietary protein paramount growth. metabolism juveniles controlled micronutrients, such vitamins minerals but there little published literature. vitamin A concentration live feeds can be important determinant normal skeletal generalized regime starts rotifers followed Artemia then formulated feeds. On weight-specific basis, tend ingest more than 100% own weight specific ingestion rate decreases age efficient digestion. Experimental microdiets allowed investigation nutritional requirements, sustain survival comparable feeds, poor. Microdiet attractiveness inclusion hydrolysates or free AA. Microbound, microencapsulated, microcoated diets used increasing effectiveness. Further improvements will come better understanding basic sparids, interactions factors, hydrodynamics developmental