The effects of feeding frequency on growth and reproduction in zebrafish (Danio rerio)

In the present study, we examined the effects of feeding regime on growth and reproductive performance in wild-type zebrafish (Danio rerio) maintained on a recirculating aquaculture system. Starting at 30 days post-fertilization (dpf), we fed 8 replicate groups of age and strain matched fish a pelleted formulated diet (Gemma Micro 300, Skretting) either once every other day (EOD), one time (1 ×), three times (3 ×) or five times (5 ×) a day to achieve a total daily feed input of 5% of body weight per day compared against a “standard” control (C) of Artemia salina nauplii/metanauplii three times daily to apparent satiation. Fish in each treatment group were weighed and measured for fork length once every other week until 150 dpf. We evaluated the effects of these feeding regimes on reproductive performance (breeding success, fecundity, and embryo viability) by setting up randomly sampled fish from each replicate groups in small group crosses (2 males, 3 females) once every other week starting at 76 dpf until the experiment was terminated at 191 dpf. Growth performance was significantly affected by feeding regime, especially in female fish, where fish in the 1 ×, 3 ×, and 5 × groups were significantly (p < 0.05, one way ANOVA) longer and heavier than fish in control and EOD groups at the end of experiment. Feeding regime had a less clear effect on reproductive performance. Mean fecundity and embryo viability varied little between groups, but the fish fed EOD, 1 × and 3 × showed significantly higher rates (p < 0.05) of breeding success than the control and 5 × groups. These results suggest that feeding regimes most conducive to growth do not necessarily maximize reproductive success in this species.