Influence of temperature and salinity on length and yolk utilization of striped bass larvae

The effects of temperature and salinity on yolk utilization and growth of larval striped bass (Morone soxatilis) from Canadian maritime stocks were studied to determine optimal rearing conditions. Larval length increased during yolk utilization and maximum length (L_max) was attained at about 70 degree-days post-hatch. Dry weight declined during yolk utilization, whereas, larval wet weight was relatively constant and only declined when yolk was depleted. Temperature and salinity significantly affected the L_max. Temperatures exceeding 18 C resulted in lower L_max. Higher L_max values were attained at 5 % than at 1 or 10 %. Time to reach L_max was longer at 5 and 10 % than at 1 % for any experimental temperature. Time to reach L_max was 3 days post-hatch longer than times to maximum embryo dry weight. The Q₁₀ of yolk utilization was 1.71, 1.53 and 2.52 at 1, 5 and 10 %, respectively. Times to terminal yolk utilization were about 1.2 d shorter than times to L_max. Morphological changes during yolk utilization indicated rapid development of locomotory and predatory capabilities. These and other developmental strategies were compared to those of salmonids. Rearing striped bass larvae at 14 -16C and 5 % throughout yolk utilization should result in longer larvae at initial first feeding.