Evolución de la maduración gonadal de ejemplares de Seriola dumerilli mantenidos en cautividad

[EN]The present work describes the evolution of Seriolla dumerilli stock in the Instituto Canario de Ciencias Marinas from year 2006 to 2009. Nine sub adults of kingfish were captured by local fisherman in the south coast of Gran Canaria in may 2006, fish were transported in a truck and transferred to on land facilities. Adaptation to tanks and inert food was successfully carried out one month after the capture. After 3 year kept in captivity 100% survival was obtained. Initial fish weight (1,66kg), was increased over to 8,0 kg nowadays. Every year fish were sampled to determine individual growth in weight and size. In addition, the evolution of its sexual maturity state was established by ovarian biopsy. Oocites over 500 microns were observed in year 2008 in one of the females with an average weight of 3,8kg. In year 2009, mature fish were observed, but natural spawn was unsuccessful, however the use of hormonal injection (LHRH) results in two successful spawn with around 0,5 millions eggs (99% unfertilized eggs).

Maduración y obtención de puestas de Seriola rivoliana en Canarias

The almaco jack Seriola rivoliana belongs to the Carangidae family of fishes. These species are an important resource for recreational and commercial fisheries worldwide. Among other attributes, almaco jack has being identified as potentially aquaculture species due to their fast growth, excellent flesh quality and significant market opportunities internationally. The present work describes the establishment of broodstock of Seriola rivoliana in the Instituto Canario de Ciencias Marinas from year 2006 to 2009 and subsequent maturation and spawning. Twenty sub adults were captured by local fisherman in the South coast of Gran Canaria in may 2006. Adaptation to culture conditions in tanks and inert food was successfully carried out just after one moth of capture. Initial fish weight (1,76± 0,25kg), was increased to 6,0±1,1kg in july 2009. Every year fish were sampled to determine individual growth in weight and size. In addition, the evolution of its sexual maturity state was established by gonadal biopsy. In July 2009, the use of hormonal injection (LHRH) results in two successful spawns with 42% of viable eggs.

Effect of larval density and feeding sequence on meagre (Argyrosomus regius Asso, 1801) larval rearing

[EN] Meagre, has been proposed as a candidate for marine finfish diversification on commercial aquaculture (Quémèner, 2002, Mateos, 2007). Despite of the elevated on growing potential, the most important bottleneck of this specie is related to the limited production of fry. Larval rearing of this species, is performed mainly adapting seabream culture techniques with different success (Roo et al., 2007) However, since limited information about the optimal feeding sequences and nutritional requirements of meagre is available, more research is needed on larval rearing protocols and nutrition. Present results (elevated larval growth rate, high survival, short rotifers period) are very promising for a successful implementation at industrial scale, which helps to solve the continues lack of fry of this specie in the Mediterranean and Canary islands.

Effects of diets, with different levels of n-3 HUFA, designed specifically for gilthead seabream (Sparus auratus L.) broodstock on spawning quality

The effects of dietary lipid levels in the spawning quality has been studied in several cultured fish species. Works like those of Watanabe et al. (1984 a); Mourente et al. (1989); Dhert et al. (1991); Bruce et al. (1993); Navas et al. (1997); Rodriguez et al. (1998); Lavens et al. (1999); Furuita et al. (2002, 2003 b); Mazorra et al. (2003); Fernandez- Palacios (2005) and Aijun et al. (2005) show that lipids and fatty acids are the dietetic components that have more influence in the spawning quality, specially in those species with continuous spawning which display short vitellogenesis periods and are able to incorporate these dietetic components in eggs during the spawning period. Diets for gilthead sea bream (Sparus aurata) broodstock with dietary levels of 2.84% n-3 HUFA, combined with levels of 250 mg/kg vitamine E rasure good spawning quality. Putting so indicative the importance for an effective utilization of essential fatty acids the use of adequate levels of antioxidants.

Desarrollo embrionario y estudio morfométrico de la fase lecitotrófica de larvas de medregal negro (Seriola rivoliana Valenciennes, 1883)

[EN]The present study describes the main embryonic stages and larval development, in culture conditions, of the almaco jack until the fifth day of life. Also a morphometric study of the eggs and larvae from induced spawning was realized. Larval hatching occurred at 36 hours from fertilization. At 60 hours after hatching, 100% of the larvae had their mouths open. At 72 hours all the larvae had a swimming bladder and a digestive tract sufficiently formed to start exogenous feeding.

Captura, aclimatación y maduración en cuatividad de reproductores salvajes de Pseudocaranx dentex en Canarias

[EN]The present work describes the procedures for capture, maintenance and evolution of a Pseudocaranx dentex stock in the Instituto Canario de Ciencias Marinas. Forty fish captured in a commercial off-shore fish farm, were transferred to on land facilities, acclimatation to tanks and inert food was successfully carried out, with 100% survival after 1 year. Initial fish weight (4,15kg) was , followed and sampled to determine individual growth in weight and size. Also, the evolution of its sexual maturity state was evaluated at capture and one year after to determine the maturation of fish for future juvenile production. Fish mature in captivity, but natural spawn was unsuccessful

Eficacia de la inducción hormonal con distintas dosis de GnRHa en corvina (Argyrosomus regius)

[EN]The objective of this experiment was to determine the efficacy of different GnRHa doses for the induction of the spawning in meagre broodstock born in captivity. Five experimental groups were established, and one control group that was not injected. Fish were acclimated in six 10 m3 tanks, and in each tank there was 3? and 4? with an average weight of 8.33±0.97 and 8.47±1.09 kg respectively. Throughout the experimental period (April 14- June 2 of 2009), broodstock were induced on a weekly basis. Each time one female and two males from each of the five experimental groups were induced with an injection of GnRHa at the doses of 10, 20, 30, 40 and 50 ?g.kg-1 respectively. No significant differences were found in any of the controlled parameters: % of injected females with spawning, latency period and % of spawns. Although the highest spawning ratio was obtained with the lower doses, a statistically significant negative correlation between the doses and percentage spawning was found.