Dataset: Growth and mortality of lobster larvae at different temperatures for lobster larvae from Gulf of Maine near Boothbay Maine from 2021 and 2022 (Lobster Thermal Thresholds project)

Homarus americanus (lsid:marinespecies.org:taxname:156134) lobster larvae were reared to the appropriate stage in lab under several different conditions. Most larvae were reared individually in an environmental control room at 18°C in 400 ml glass jars in 0.45 µm filtered seawater and fed fresh hatched brine shrimp ad libitum. Water changes were made every 2-3 days. Alternative rearing conditions included 14°C and fed fresh hatched brine shrimp, ambient seawater temperature (jars were held in a water bath of flow through seawater) fed fresh hatched brine shrimp, and 18°C and fed a diet of live, freshly collected zooplankton from local waters. We also conducted trials on wild caught stage IV larvae. Larvae were collected using a neuston net (0-0.5 m depth) in the vicinity of Boothbay, Maine, USA. Wild larvae were held in individual jars at ambient seawater temperature until trials could be conducted. 

 

To assess growth and mortality, larvae were transferred from their rearing condition to the treatment temperature and maintained at the treatment temperature until they either molted to the next developmental stage or died. Larvae were transferred in their jar at the rearing temperature to the treatment temperature without exchanging the water, which allowed for a gradual temperature change. Feeding and water changes continued as described for rearing conditions. When larvae molted to the next developmental stage, they were photographed for carapace length measurements and frozen individually. Measurements of carapace length were made from the posterior edge of the ocular cavity to the midline of the posterior edge of the carapace using ImageJ. Frozen larvae were subsequently dried for 24 hours at 60 °C and weighed.  Larvae dying during the experiment were not measured or weighed.