Effects of temperature on initial swim bladder inflation and related development in cultured striped trumpeter (Latris lineata) larvae

Abstract

Many physoclist fish have physostomous larvae, initially inflating the swim bladder by ingesting air at the water surface during a brief, finite period. Failed initial swim bladder inflation has been predominantly linked to abiotic factors and larvae which fail to complete initial swim bladder inflation exhibit reduced survival and growth. This study investigates the effects of temperature on initial swim bladder inflation, survival and post-inflation viability (surviving larvae with inflated swim bladders) in striped trumpeter (Latris lineata) larvae. Growth, developmental stages and stagespecific larval size are examined in relation to initial swim bladder inflation. Larvae were reared at 12, 14, 16 or 18 jC (Experiment 1) or at 15, 17, 19 or 21 jC (Experiment 2) from day 1 posthatching in replicated 200-l tanks. Initial swim bladder inflation was significantly affected by temperature, with highest initial swim bladder inflation at 14 jC (67.8F5.9% S.E., n=3) to 16 jC (71.1F4.8%) and 15 jC (72.2F1.1%) to 17 jC (76.6F12.0%) in Experiments 1 and 2, respectively. Survival was also significantly influenced by temperature, with the highest survival at 16 jC (31.2F4.9%) to 18 jC (30.6F4.0%) in Experiment 1, and 17 jC (12.4F2.4%) to 19 jC (9.6F2.8%) in Experiment 2. In both experiments, the highest post-inflation viability occurred through a combination of maximum initial swim bladder inflation and survival, at 16 jC (21.3F2.1%) and 17 jC (9.5F1.8%) in Experiments 1 and 2, respectively. Reduced post-inflation viability at 18 and 19 jC was due to decreased initial swim bladder inflation, not survival. The reverse trend was apparent at lower temperatures where survival was significantly lower at 14 and 15 jC, but initial swim