Dataset: Lobster Larvae Respirometry Data

Microrespirometry trials were conducted on planktonic larval stages I, II, III, IV and benthic stage V at temperatures ranging from 4-32°C.  We used a Unisense MicroRespiration System (https://unisense.com/products/microrespiration-system/), with SensorTrace Rate software and Oxygen MicroOptode MR optical oxygen sensors.  Sensors were calibrated at 0 and 100% oxygen saturation at each treatment temperature prior to experimental trials.  Larvae were held at held at 18°C until the time of the experiment when they were transferred to a 20 ml vial and placed in a water bath at the treatment temperature for a 10-minute acclimation period.  Acclimated larvae were transferred to respiration chambers filled with 0.45 µm filtered sea water at treatment temperature and lowered into the water bath for a 20-minute respirometry trial.  4 ml respiration chambers were used for stages I-III and 40 ml for stages IV and V.  Only one larva was used in each chamber.  Magnetic stir bars were used in all trials.  In trials for resting oxygen consumption rate, a stainless steel mesh separated the larva from the stir bar.  In the actively swimming trials the mesh was removed and movement of the stir bar prevented the larva from resting on the bottom.  Controls were run using respiration chambers with 45 µm filtered sea water and no larva.  The first 10 minute of data collected during the trial were discarded as it often required time to reach a linear rate of oxygen consumption.  The rate of oxygen consumptions was determined for approximately the last 10 minutes of the trial using Unisense SensorTrace Rate software.  After the trial was completed the larvae were rinsed with DI water, frozen individually, and subsequently dried at 60°C for 24 hours to obtain dry weight of individuals.  When dry weight for an individual was not available and average values for the season was used.  Oxygen consumption rate as normalized to dry weight of the individual larva.

Larvae were reared 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 sea water temperature until trials could be conducted.