EFFECT OF TEMPERATURE ON DEVELOPMENT RATE OF LARVAE FROM COLD-WATER AMERICAN LOBSTER (HOMARUS AMERICANUS)

The duration of the larval phase of the American lobster influences the distance larvae drift, and thus the potential settlement and recruitment patterns of lobsters to local populations and fisheries. The duration of larval stages is influenced by temperature, with warmer temperatures resulting in faster development and shorter stage duration. The quantitative relationship between temperature and duration of larval stages has been previously investigated, but only for lobsters originating from relatively warm-water regions. We examined the effects of temperature on stage duration for lobster larvae originating from a cold-water region, the northern shore of the Gaspe Peninsula in the northern Gulf of St. Lawrence, Canada. We reared larvae individually using a new experimental apparatus with automated movement of culture containers to facilitate water exchange. We compared observed duration of larval stages for these cold-water source larvae to durations in previous studies that used warmer-water source larvae. We observed 38% shorter development times at the coldest temperature used (10 degrees C) and 47, 50, and 100% longer development times at warmer temperatures (14, 18 and 22 degrees C, respectively) than at the same temperatures in previous studies of warm-water larvae, suggesting potential geographic variation in the functional relationship between temperature and larval development time. Given these results, future research should examine this question in more detail, to enhance understanding of lobster ecology and population dynamics across the species' range.