Artemia biomass: A functional live maturation feed for Indian white shrimp, Penaeus indicus broodstock, and its culture prospective under diverse management regime

Artemia biomass production in a controlled biosecure system can be popularised in inland or coastal areas where accessibility to saltpan is limited. Against this background, four sets of experiments were executed to optimize different management regimes in Artemia biomass production, and to explore its role as a maturation diet for Indian white shrimp, Penaeus indicus. In experiment, I, Artemia biomass production was carried out in autotrophic (microalgae, TA), heterotrophic (TH), and mixotrophic (TMX) rearing systems for 18 days. Experiment II was conducted to evaluate Artemia biomass production under diverse salinity regimes (10, 15, 20, 30, 40, and 50 ppt), and in experiment III, the effect of varying stocking densities of Artemia (300, 600, 1200, and 1800 nos L−1) in production was attempted. In experiment IV, the role of adult Artemia (live, frozen, and hormone-enriched) as a maturation diet for P. indicus (36.40 ± 0.3 g) was explored, and the sex steroid profile of adult Artemia was compared with other fresh maturation feeds (polychaete, clam, and squid). At the end of Exp 1, significantly higher (P < 0.05) yields were recorded in mixotrophic (1.30 ± 0.95 kg m−3) and heterotrophic groups, (1.22 ± 0.15 kg m−3) compared with autotrophic units (0.36 ± 0.47 kg m−3). However, omega 3 fatty acids (13.92 ± 0.73%) were highest in the autotrophic system compared to TMX (11.97 ± 0.84%) and TH (8.71 ± 0.31%). In Exp II, the highest (p < 0.05) production (1.52 ± 0.13 kg m−3) was recorded at 50 ppt followed by 40 ppt (1.29 ± 0.08 kg m−3) and the lowest at 10 ppt (0.54 ± 0.01 kg m−3). The highest egg-bearing population (%) was recorded at 40 ppt (30.47 ± 3.09%) followed by 30 ppt (12.63 ± 0.82%) and 50 ppt (9.29 ± 0.80%) while none of the Artemia got matured at lower salinity treatments. The stocking density-dependent inverse relation (p < 0.01) in survival (17–67%) was registered among the treatments in Exp III with no variation (p < 0.05) in total productivity (1.26 to 1.10 kg m−3). At the end of Exp IV, 100 ± 0, 87.5 ± 7.2, and 46.6 ± 3.3% of the broodstock fed with enriched, live, and frozen Artemia had matured ovaries, respectively. A comparative analysis of sex steroids in Artemia and other fresh broodstock feeds revealed the highest (p < 0.01) 17-β-estradiol level in polychaete (998 ± 33 pg 100 mg) followed by Artemia (519 ± 28 pg 100 mg−1), clam (195 ± 29 pg 100 mg −1) and squid (61 ± 10.69 pg 100 mg−1). The study indicated mixotrophic system with 300 no L−1 density at 40 ppt can yield the optimal highest production with a better nutritional profile and higher matured population. This strongly suggests the flexibility of mixotrophic-based culture units compared with a single food source system. The presence of sex steroids in adult Artemia provides its scope as a quality fresh maturation diet and can open new vistas for its wide acceptability as SPF live maturation diet for commercial shrimp hatcheries.