Maternal size effect on larval growth, development, and respiration rates in the American lobster (Homarus americanus)

The American lobster (Homarus americanus) is the most valuable single-species fishery in the United States, and Maine harvests 80% of it [NOAA, 2014]. The Gulf of Maine is warming at an unprecedented rate and has experienced its warmest decade year on record. As temperatures warm, the lobster population has exhibited a significant downward trend in the size of reproductive maturity. In this study we investigated the impact of maternal size on larval growth, development and respiration rates. Larvae from large (107-136 mm carapace length [CL]) and small (81-93 mm CL) egg-bearing females from mid-coast, Maine were reared separately in the laboratory at 16°C and fed an abundance of brine shrimp. Our results show that newly hatched stage I larvae reared from small females were significantly smaller, developed more slowly, and consumed less oxygen per milligram of mass than those from large females. These results suggest that compared to their larger counterparts, smaller female lobsters not only produce fewer eggs, but may also produce inferior larvae. Further study of maternal size effects could enhance our understanding of the impact of climate change on the sustainability of this iconic fishery.