Study Case on Controlled Breeding and First Growth Steps of Chiloscyllium puctatum

Abstract

Such study, conducted at Acquario di Cattolica (Rimini, Italy), lasted six months of observations on Chiloscyllium punctatum reproductive biology. It is an oviparous species present in many aquaria around the world, but the fishing effort, habitat destruction and constant samples taking have led to a drop in the number of wild populations (IUCN red list). Looking at the current low level of reproductive standard protocols, we tried to collect the greatest number of useful information in order to obtain a reproductive protocol. The couple of adults, cohabiting in a tank with other species, were breeding and maintained in stable environmental conditions (i.e. T °C, % and pH). When deposition occurred, the eggs were moved in 5 expository trays (Themes-5), ex-novo settled up. These trays allowed the monitoring of embryonic development till hatching 120 ± 10 days post deposition (dpd). Newborns were measured by total length (TL, cm) to quantify the growth (Von Bertalanffy Growth Function, VBGF) and the growth rates (GR), therefore weaned from yolk sac. They were feeded 3 times per week, by a specific diet based on shrimp (Pandalus borealis), capelin (Mallotusvillosus), codfish (Merlucciusmerluccius) and mackerel (Scomberscombrus). Besides, it was setted a light gradient (1 lx 0.05). Shrimp (P. borealis: 3 cal/1 gr) resulted the food with the best performance. The adults produced 33 newborns depositing 2 eggs per week. These observations have made possible to provide useful information on shark deposition, hatching, diet and newborn growth.