P. L. Shafland

Hydrilla Consumption by Triploid Hybrid Grass Carp in Aquaria

Triploid hybrid grass carp (Ctenopharyngodon idella x Hypophthalmichthys nobilis) were provided known weights of hydrilla (Hydrilla verticillata) in 300 liter aquaria, to determine consumption rates for age I hybrids from 6 size groups, 21 to 37 cm total length (TL). Mean consumption rates for these groups at 26° C ranged from 25% to 52% of their body weight/day (% BW/D) or 1.7 to 8.6 g dry weight of hydrilla/day (g DW/ D). Smaller hybrids generally ate less hydrilla than larger fish, but expressed as a percentage of their body weight, small hybrids consumed more than large hybrids. The...