Effect of Timing of First Feeding on Survival and Growth of Obscure Puffer (Takifugu obscurus) Larvae

ABSTRACT

The effect of timing of the first feeding (2, 3, 4, 5, 6, 7, and 8 days post-hatch, dph), on survival and on growth of laboratory-reared obscure puffer (Takifugu obscurur) larvae was examined. Larvae began to feed exogenously at 2–3 dph (2.96±0.05 mm in total length) at 24 °C. Survival of larvae initially fed at 2, 3, 4, and 5 dph was similar (73.2–78.8%), while survival decreased sharply for those larvae whose first feeding was at 6 dph (22.1%), and no larvae were able to survive when food was not offered until 7 and 8 dph. The feeding incidence of larvae fed for the first time at 2, 3.4, and 5 dph reached 100% in 24 h, whereas the feeding incidence decreased gradually in the larvae fed for the first time at 6 and 7 dph, and no feeding occurred in the larvae introduced to food at 8 dph. According to the feeding incidence, the point of no return occurred between days 6 and 7 after hatching. After 18 dph, no statistically significant differences in mean total length were detected among the larvae fed for the first time at 2, 3, 4, and 5 dph, while the larvae fed for the first time at 6 dph were significantly smaller. To ensure a successful transition from endogenous to exogenous feeding, timing of first feeding of obscure puffer larvae must be before 5 dph.