Maturation diet based on fatty acid content for male Penaeus monodon (Fabricius) broodstock

Abstract

The contents of three essential fatty acids, arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), from wild Penaeus monodon broodstock were evaluated in comparison with natural diet fed P. monodon. Spermatophores of wild male broodstock contained higher levels of AA than those of arti¢cial diet fed males. Polychaetes had higher proportion of AA to EPA and DHA at 5.8:5.5:1 in mud polychaetes followed by 12:7:1 in sand polychaetes, while DHAwas a preferential n-3 highly unsaturated fatty acid (HUFA) in squids and ¢sh. The experimental feed was constructed to simulate the HUFA pro¢le of polychaetes (AA:EPA:DHA as 5:1:1) and then fed to farmed male black tiger prawn broodstock for 1 month. The results exhibited comparable reproductive characteristics to wild male suggesting the possibility of replacing wild males with pondreared males. Rearing farmed males in a test unit for a month did not reduce the quality of prawn sperm. Reproductive performance indices (sperm sac weight, total number of sperm, percentage of live sperm, percentage of abnormal sperm) from the males of all treatments were not statistically di¡erent except in males fed with pellets. Control (live feeds) and combined diet provided better reproductive performance in pond-reared males. Analysis of AA, EPA and DHA in reproductive tissues, hepatopancreas and muscle of treated animals in each treatment revealed an accumulation of dietary HUFA into reproductive tissues. No evidence of transfer of HUFA from hepatopancreas or muscle to spermatophore was found.

Nutritional status of a nereidid polychaete cultured in sand filters of mariculture wastewater

“…Because it is a precursor to steroid hormones and comprises a large proportion of the lipid in crustacean eggs and because they cannot synthesize it or substantially replace it with other dietary sterols (Harrison 1990), it is likely that maturing broodstock would require greater levels than immature shrimp. Compared with levels of 0.3-0.4% recommended for diets of nonmaturing shrimp (Akiyama & Dominy 1989) and inclusion levels ranging from 0.25 to 0.5% in maturation diets for P. vannamei (Cahu et al 1994) and P. monodon (Meunpol et al 2005) respectively, the levels found in P. helleri in the present study (5-10 g kg À1 of DM) appear adequate. This was up to twice the cholesterol levels reported for cultured P. nuntia in Thailand (3-5 g kg À1 of DM: Limsuwatthanathamrong et al 2012).…”

“…This was similar to the lipid levels reported for Perinereis sp. by Meunpol et al (2005) ) were lower than levels found by Brown et al (2011) in N. virens (130-170 g kg…”

“…In particular, marine fish and shrimp broodstock are known to have requirements for a range of essential fatty acids which they cannot synthesize themselves (Izquierdo et al 2001;Wouters et al 2001). These have traditionally been supplied by lipids in live and fresh/frozen diets mainly comprising a range of marine organisms including squid, bivalve molluscs, crustaceans and polychaetes (Marsden et al 1992;Meunpol et al 2005;Hoa et al 2009). Although polychaetes are the most expensive of these diets, they are widely considered indispensible in commercial penaeid maturation diets (Harrison 1990;Kawahigashi 1998).…”

“…Meunpol et al (2005) documented a higher ratio of ARA compared with EPA (and DHA) in both sand (Perinereis sp.) and mud (Marphysa sp.)…”

“…Wild fisheries have traditionally serviced these needs, but increasingly, polychaetes are commercially cultured for leisure fishing and marine hatchery applications (Olive 1999;Poltana et al 2005;Palmer 2010;Limsuwatthanathamrong et al 2012). Polychaete inclusions in shrimp maturation diets tend to range from 5 to 33% (Meunpol et al 2005;Coman et al 2007), where they are preferred offered live, but for convenience are also supplied after thawing or in compounded forms. Despite their relatively high cost, their demand for use as bait and their functional advantages and preferences for use over other broodstock feeds have contributed to overexploitation, environmental impacts and market undersupply in several countries (Scaps 2003).…”