Marine and freshwater crab meals in diets for the red porgy (Pagrus pagrus): growth, colour, and fish composition

[EN] Red porgy, Pagrus pagrus, is one of the marine fish species for the aquaculture diversification in the Mediterranean and Mid Atlantic coasts. Relevance of its nutrition has been demonstrated not only from growth and body composition, but also because it?s important role in fish skin colour and carotenoids deposition (Kalinowski et al., 2005; Pavlidis et al., 2006). Present study evaluate the influence of two different crab meals by products, marine and freshwater origin, as protein and pigment sources in experimental diets for red porgy and its effects on fish growth and feed utilization parameters, fish skin colour and fish composition. Both crab meals used in present study are suitability as partial replacers of fish meal in diets for the red porgy. Dietary inclusion levels of 10% and 20% of the dietary protein from these meals have no detrimental effects on growth and feed utilization parameters respect to a fish meal based diet, with high improvements in fish skin redness and skin colour saturation by increased inclusion levels. Digestibility and retention efficiency parameters are being analyzing at the moment.

Enhancement of gilthead sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) larval growth by dietary vitamin E en relation to diffetent levels of essential fatty acids

[EN]Most marine fish larvae require high amounts of n-3 HUFA (highly unsaturated fatty acids) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (Watanabe, 1982; Izquierdo, 1996). Fish larvae tissue lipids are also very high in n-3 HUFA, what implies a higher risk of peroxidation (Sargent et al. 1999) and cellular damage (Kanazawa, 1991), requiring then antioxidants to protect them intra- and extra-cellularly from free radical compounds. Vitamin E (Vit E) functions as a chain breaking antioxidant, reacting with the lipid peroxide radical produced and preventing the further reaction with a new PUFA. Hence their requirements are related with the dietary and tissue PUFA contents. The objective of the present study was to determine the effect of dietary Vit E on gilthead sea bream and sea bass survival, growth and stress, at different n-3 HUFA levels.

Combined levels of carotenoids and vitamin E in diets for gilthead seabream broodstocks (Sparus aurata L.): effect on the quality of egg spawning and composition

Watanabe et al. (1991 a,b) state that, vitamin E and carotenoids perform an essential role on the quality of egg spawning. Vitamin E is one of the main nutrients for the reproduction of fish (Izquierdo et al., 2001), and it has been proved that its inclusion in diets for broodstocks favors the quality of egg spawning in several species of fish (Watanabe and Takashima,1977; Takeuchi et al., 1981; Watanabe et al., 1985, 1991 a,b; Sutjaritvongsanon, 1987; Watanabe, 1990; Schimittou, 1993; Mushiake et al., 1993; Dube, 1996; Shiranee and Natarajan, 1996; Izquierdo et al., 2001; Morehead et al., 2001; Fernández- Palacios et al., 2005). On the other hand, the carotenoids which also perform an antioxidizing function (including the protection of lipids from oxidation), have been involved in the reproductive processes of marine organisms: crustaceans (Liñan-Cabello et al., 2002), marine fish (Watanabe y Kiron, 1995; Verakunpiriya et al., 1997 a,b; Vassallo-Agius et al., 2001 a,b,c, 2002; Watanabe and Vassallo-Agius 2003) and fresh water fish (Ahmadi et al., 2006). The results of this study suggest that the recommended levels of n-3 HUFA in diets for gilthead sea bream broodstocks could be increased up to 3,5 % when supplemented jointly with carotenoids from paprika oleoresin and vitamin E, thus favoring the quality of spawning.

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.

Effect of rotifers fatty acid composition on the occurrence of skeletal deformities in red porgy Pagrus pagrus (Linnaeus, 1758)

Red porgy has been proposed as a candidate for diversification of marine aquaculture production (Hernández-Cruz et al., 1999). However, limited larval survival together with the elevated levels of skeletal deformities occurrence (over 50% of the population), under intensive or semi-intensive systems constitute the major bottlenecks for the production of this species at commercial scale (Roo et al., in press). Essential fatty imbalances on early life stages, may alter the osteological development of reared larvae (Cahu et al., 2003). The objective of this study was to determine the effect of rotifers enrichment, particularly on DHA, on growth, survival and occurrence of skeleton deformities in red porgy.

Use of different commercial Artemia sp. Enrichements in Octopus Vulgaris, paralarval rearing at initial planctonic phase: effects on growth, survival and fatty acid composition of the paralarvae

[EN] Octopus "paralarvae", are planktonic, swim actively and have high metabolic rates, requiring large quantities of live prey of adequate motility and nutritional quality ( Iglesias et al., 2000; Navarro and Villanueva, 2000, 2003). During the planktonic phase, they undergo strong morphological changes, after which the octopuses start settling to the bottom. The potential of Octopus vulgaris as candiadate for diversification of marine aquacultures are mainly due to its high food conversion rate and fast growth.( Iglesias et al 2006). Despite the research effort taken until now, paralarval rearing of O. vulgaris still suffers high mortalities which limited the industrial culture of this species. The main problems in the paralarval rearing stages are the high mortality rates and poor growth. These are attributed to the lack of standardized culture techniques and nutritional deficiencies in the diet of paralarvae, especially in n-3 highly unsaturated fatty acids (n-3 HUFA). The objective if this experience was to test different commercial live prey enrichment to improve nutritional quality of the artemia.

Growth and fatty acid composition of Octopus vulgaris fed different diets based on bogue (Boops boops) in comparison to wild individuals

[EN] Octopus vulgaris is a suitable candidate to diversify marine aquaculture (Iglesias et al., 2000; Vaz Pires et al. 2004). Actually, wild sub-adults are on-growing in floating cages showing promising results (Chapela et al., 2006; Rodríguez et al., 2006). Even though octopus industrial development is still limited, mainly associated to the dependence of wild catch individuals for ongrowing (Iglesias et al., 2007) and a lack of an appropriate formulated diet (García García and Cerezo, 2006). In addition, essential macronutrient requirements for this species are still not well known. Used of discarded bogue as single food for Octopus on-growth results in similar growth than co-fed diets with the crab (Portunus pelagic). FA content of Muscle and DG showed important ARA content, suggesting the important functions of this FA in this specie.

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.

Opportunity of integrated production of "Ceratophyllum demersum" in a nutrition trial with "Carassius auratus"

[EN]The integrated culture of fish and plant in a recirculated system is called aquaponics, where a mutual benefit have been demonstrated for the cocultured species. Today this practice is still not well known for the most studied consumed freshwater species, and almost nothing has been done for aquarium species. The objective of present work was to study the opportunity of growing one of the most selled aquarium plant coontail (Ceratophyllum demersum) in a coculture with the goldfish (Carassius auratus) from which a nutritional trial was planned.