Organogènesi i aspectes patològics del desenvolupament del dentó

Common dentex ("Dentex dentex") is one of the most promising new species for Mediterranean aquaculture. However, its larval rearing still faces several important problems which have to be solved before industrial production is undertaken. The aims of the present investigation are the optimization of the broodstock in captivity and the increase of larvae survival in the rearing system. Three different aspects will be studied: a) reproductive aspects; in order to elucidate the reproductive behaviour of this species, histological studies of ovaries of wild individuals during the spawning period (April-May) willbe carried out. On the other hand, spawning parameters of cultured specimens (number of eggs, hatching rate, fertility, survival...) will be studied; b) nutritional aspects throughout development; an estimate of the utilization of endogenous nutrients from the yolk sac which occurs during embryonic and early larval development will be a first approach to study the nutritional requirements of the larvae. The determination of the requeriments in (n-3) HUFA will be performed by using emulsions, containing different levels of these essential fatty acids, as enrichers for the live preys previous to weaning; c) morphological aspects of the development of the embryo and larvae; in order to determine the cause of the high mortality rate during larvar rearing, histological and histopathological events throughout development will be studied. Morphological, morphometrical as well as organ an tissue growth studies of the larvae will be carried out in relation to the diet administered.