Co-feeding of live feed and inert diet from first-feeding affects Artemia lipid digestibility and retention in Senegalese sole (Solea senegalensis) larvae

Abstract

The present study intended to evaluate the effects of early introduction of inert diet in lipid digestibility and metabolism of sole, while larval feed intake, growth and survival were also monitored. Solea senegalensis larvae were reared on a standard live feed regime (ST) and co-feeding regime with inert diet (Art R). Trials using sole larvae fed with Artemia enriched with two different lipid emulsions, containing glycerol tri [1-, were performed at 9 and 17 days after hatching (DAH) to study lipid utilization. Co-feeding did not affect sole survival rates (ST 59.1 ± 15.9%; Art R 69.56 ± 9.3%), but was reflected in significantly smaller final weight at 16 DAH (ST 0.71 ± 0.20; Art R 0.48 ± 0.14 mg). Higher feed intake was observed in sole larvae fed on Artemia enriched with labeled PL at 9 DAH but not at 17 DAH. At 17 DAH, the smaller larvae (Art R treatment) ingested proportionally more Artemia in weight percentage, independently of enrichment. At 9 DAH lipid digestibility was equal among treatments and higher than 90%, while at 17 DAH it was higher in ST treatment (around 73%) compared to the Art R group (around 66%). Lipid retention efficiency at 9 DAH was higher in the Art R treatment, reaching values of 50%, while these values almost duplicated at 17 DAH, ranging up to 80% in both treatments without significant differences. These results show that co-feeding of live feed and inert diet from first-feeding in Senegalese sole has a toll in terms of growth and lipid digestibility but does not seem to compromise lipid metabolic utilization.

Cortisol response to air exposure in Solea senegalensis post-larvae is affected by dietary arachidonic acid-to-eicosapentaenoic acid ratio

“…Assuming that lipid digestibility is high in Senegalese sole post-larvae, especially that of LC-PUFA Mai et al 2009), the identification of the preferential metabolic fate of fatty acids should be possible by comparing fish fatty acid profiles with those presented in the diets. Delta values for C18 fatty acids, like OLA and particularly ALA, provide indication that these were preferentially metabolized, likely for energy production purposes through b-oxidation, as observed in various fish species (Bell et al 2001;Tocher 2003;Morais et al 2006).…”

“…Larval rearing depends greatly on live feed supply, and various studies during these life stages have focused on weaning strategies (Engrola et al 2009a(Engrola et al , b, 2010Mai et al 2009). In hatcheries, during metamorphosis, it is common practice to gradually replace live feed with frozen Artemia metanauplii, generally enriched in lipids.…”

<b>Development of the digestive system in larvae of the Neotropical fish <i>Prochilodus argenteus</i> (Characiformes, Prochilodontidae)

“…The larvae of different species are fed on Artemia sp. nauplii to adapt or optimize the digestion process, which may involve a gradual transition period of co-feeding with live feed and inert feed or an abrupt transition between the two forms of feeding (Ballagh, Fielder & Pankhurst, 2010;Bonaldo, Parma, Badiani, Serratore, & Gatta, 2011;Chepkirui-Boit et al 2011;Engrola et al, 2009;Mai et al, 2009). The index of larvae survival in current experimental conditions was 55%, which suggests that the supply of Artemia sp.…”

Novel methodologies in marine fish larval nutrition

“…However, in sole co-fed a high Artemia replacement level (58% of total diet) both Artemia protein digestibility and retention efficiency decreased between 6 and 15 DAH (Engrola et al 2009b). Concerning lipid utilisation, Mai et al (2009) observed that Artemia replacement strategy in Senegalese sole has a toll in terms of growth and lipid digestibility but does not seem to compromise lipid metabolic utilisation. Lipid Fish Physiol Biochem (2010) 36:1-16 3 retention efficiency before metamorphosis was higher in co-fed sole, reaching values of 50%, while these values almost doubled during metamorphosis climax, ranging up to 80%.…”