Effects of Dietary Arachidonic Acid (20:4n-6) Levels on Growth Performance and Fatty Acid Composition of Juvenile Eel, Anguilla japonica

Abstract

This study was conducted to evaluate the effects of dietary arachidonic acid (AA, 20:4n-6) levels on growth performance and body composition in juvenile eel, Anguilla japonica. Six semi-purified experimental diets were formulated to be isonitrogenous and iso-caloric containing 55.0% crude protein and 15% crude lipid (18.3 kJ of available energy g -1 ). Six different levels of AA were added to the basal diet, with 0, 0.2, 0.4, 0.6, 0.8 or 1.2% on a dry matter (DM) basis, respectively (AA 0.07 , AA 0.22 , AA 0.43 , AA 0.57 , AA 0.78 or AA 1.23 ). After a conditioning period, fish initially averaging 27±0.5 g (mean±SD) were randomly distributed into each aquarium as triplicate groups of 20 fish each. One of six experimental diets was fed on a DM basis to fish in three randomly selected aquaria at a rate of 2-3% of total body weight twice a day. At the end of the 12-week feeding trial, weight gain (WG) and feed efficiency (FE) of fish fed AA 0.78 and AA 1.23 diets were significantly higher than of fish fed AA 0.07 , AA 0.22 and AA 0.43 diets (p<0.05). Specific growth rate (SGR) of fish fed the AA 0.78 diet was significantly higher than of fish fed AA 0.07 , AA 0.22 and AA 0.43 diets (p<0.05). However, there were no significant differences in WG, SGR and FE among fish fed AA 0.57 , AA 0.78 and AA 1.23 diets (p>0.05). Whole body AA deposition of fish fed the AA 1.23 diet was significantly higher than for the other diets (p<0.05). Broken-line model analysis on the basis of WG and SGR indicated that the dietary AA requirement could be greater than 0.69% but less than 0.71% of the diet in juvenile eel. The growth-promoting activity of AA observed in the present study provides strong support for the contention that dietary AA is essential for juvenile eel.

Towards the optimization of performance of Atlantic salmon reared at different water temperatures via the manipulation of dietary ARA/EPA ratio

“…A growthpromoting activity of dietary ARA in different fish species, particularly during juvenile stages, has been reported. For example, in juvenile eel (Anguilla japonica) dietary ARA inclusion has been shown to be essential for normal growth (Bae et al, 2010), and similarly the importance of dietary ARA inclusion in larvae of sea bass (Dicentrarchus labrax) and sea bream (Sparus aurata) has been reported (Atalah et al, 2011;Bessonart et al, 1999). In juvenile Japanese seabass (Lateolabrax japonicus) and juvenile Synechogobius hasta it has been shown that dietary ARA significantly enhanced growth and protein content of the whole body and the liver (Luo et al, 2012;Xu et al, 2010).…”

Characterization of pathogenic bacteria in eel Anguilla bicolor bicolor

“…Based on data from the FAO (2016), the global market demand for eel was 285,342 tons/year with a price range between Rp 150,000/kg-Rp 255.000/kg. This high demand of eel due to its advantages including the flesh is soft, tastes good, and contains important nutrients like DHA, EPA, and vitamin A (Bae et al, 2010).…”

Novel Feed from Invasive Species is Beneficial to Walleye Aquaculture

“…Several studies have indicated the importance of ARA in fish metabolism, and it is known to be the main fatty acid precursor of eicosanoids in fish (Bell and Dick 1990;Bell et al 1994Bell et al , 2016Atalah et al 2010;Yuan et al 2015). In addition, research has been conducted on dietary ARA in several fish species, and these studies have confirmed that elevated ARA can improve growth and survival (Bessonart et al 1999;Bell and Sargent 2003;Bae et al 2010) as well as resistance to handling stress (Koven et al 2001). In addition to the selective incorporation of ARA in COM Walleye juveniles, we also observed a higher selective incorporation of DHA in COM fish compared to EXP fish.…”