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 saxatilis) from Canadian maritime stoc ks were studied to determine optimal rearing conditions. Larval length increased during yolk utilization and maximum length (L(max)) was att ained at about 70 degree-days post-hatch. Dry weight declined during y olk utilization, whereas, larval wet weight was relatively constant an d only declined when yolk was depleted. Temperature and salinity signi ficantly affected the L(max). Temperatures exceeding 18 degrees C resu lted in lower L(max). Higher L(max) values were attained at 5 parts pe r thousand than at 1 or 10 parts per thousand. Time to reach L(max) wa s longer at 5 and 10 parts per thousand than at 1 parts per thousand f or any experimental temperature, Time to reach L(max) was 3 days post- hatch longer than times to maximum embryo dry weight. The Q(10) of yol k utilization was 1.71, 1.53 and 2.52 at 1, 5 and 10 parts per thousan d, respectively. Times to terminal yolk utilization were about 1.2 d s horter than times to L(max). Morphological changes during yolk utiliza tion indicated rapid development of locomotory and predatory capabilit ies. These and other developmental strategies were compared to those o f salmonids. Rearing striped bass larvae at 14-16 degrees C and 5 part s per thousand throughout yolk utilization should result in longer lar vae at initial first feeding.