Mysid culture: lowering costs with alternative diets

Abstract

During mysid culture, Artemia nauplii are traditionally used as food, with the high price of Artemia cysts adding significantly to production costs. In contrast, rotifers (Brachionis plicatilis) are cheaper to produce. As the effects of feeding rotifers to mysids is not well known, the effects of a partial and a total replacement of Artemia nauplii with rotifers were tested in a flowthrough culture system. Mysids used in this study were identified as Leptomysis sp. The three diets tested were: (1) 33% Artemia nauplii + 66% rotifers; (2) 100% Artemia nauplii; and (3) 100% rotifers. Production was similar for diets 1 and 2 (P > 0.05), but significantly lower for diet 3 (P < 0.01). Survival of spawning adults fed diets 1 and 2 was the same (P > 0.05), but spawning adults fed diet 3 (rotifers alone) had significantly lower survival (P < 0.05). In a similar way, hatchling survival was the same for diets 1 and 2 (P > 0.05), but hatchlings fed rotifers alone (diet 3) had significantly lower survival (P < 0.05). In 34 days, mysids fed diets 1, 2 and 3 grew up to 6.7 mm, 6.6 mm and 5.2 mm respectively. Surprisingly, mysid growth was similar among the three diets for 20 days. After 20 days, mysids fed 100% rotifers grew less than mysids fed the other diets. In general, the production, survival and growth of mysids fed the rotifer-exclusive diet was significantly lower than those of the other diets (P < 0.05). Based on the results, the following feeding regime is recommended: (1) feed rotifers during the first 20 days of the life cycle and then (2) feed a diet of Artemia nauplii (33%) and rotifers (66%). This will enhance the large-scale culture of mysids by reducing the cost of their production.