Pikeperch larviculture (Sander lucioperca [L., 1758]) with Brachionus plicatilis (Mueller, 1786) (Rotifera) and Apocyclops panamensis (Marsh, 1913) (Copepoda)

Abstract

AbstractThe effect of live feed diets containing Brachionus plicatilis (B) and Apocyclops panamensis (A) was investigated on pikeperch larval survival, growth, and fatty acid composition in two experiments (E1 and E2). Up to six different diets were provided to the larvae, in which the letters of the diet names represent the live feed organisms as mentioned above and the subsequent number of feed organisms per larva and day. In E1, start cultures with 35 larvae/L were supplied with two diets (B200 and B100 + A100) 7 days until 10 days post hatch (dph). In E2, 50 larvae/L were fed six diets, B280 + A120, B340 + A60, B400, B420 + A180, B510 + A90, and B600. The highest survival and specific growth rates (SGR) occurred in B200 (E1). In E2, B340 + A60 performed best. A trend of increasing survival rates was found in E1 from 68.9% (B100 + A100) to 71.6% B200 and in E2 from 64.0% (B280 + A120) to 93.7% (B340 + A60). Larval SGR tended to increase with higher shares of dietary B. plicatilis in both experiments. The polyunsaturated fatty acid, linoleic acid (LA), followed the same pattern as survival and SGR increasing until a plateau was reached, indirectly indicating a feeding threshold. B. plicatilis provided the LA to pikeperch larvae, which seemed to play an important role in this feeding period. Consequently, a live feed diet should contain at least 340 B. plicatilis ind. larva−1 day−1 and 6.3 B. plicatilis per milliliter until 10 dph to improve pikeperch larviculture.