Fig 1.
Length distributions of larvae at the start of the starvation experiment (T = 0; Age = 7 days).
Pink bars represent the fast-growing larvae and blue bars represent slow growing larvae for each line (wild and AQF1). A total of 60 larvae were measured for each cohort (Wild/Fast, Wild/Slow, AQF1/Fast, AQF1/Slow). The purple region indicates the overlap in size between the two groups for each line.
Fig 2.
Schematic of the experimental design.
Fig 3.
Total organic carbon (A) and total dissolved nitrogen (B) in water collected directly from the Choptank River, the Cartridge Filtration System (CFS) used for experiments, and water from the filtration system with an additional carbon filter (CFS carbon). Additionally, water samples were collected from fed and starved treatments during water changes for comparison. Samples from the buckets were taken after approximately 24 hours of larval culture. Asterisks indicated water samples that are significantly different.
Fig 4.
Survival over time for each cohort.
The starvation period lasted from age 7–17 days (indicated by the blue box on the x-axis) at which time (T = 10 days) food was reintroduced and the recovery period began. Fed controls (top) began setting to the sides of the buckets by 15 days old (T = 8 days) and thus the plot is truncated. Inset shows closer detail of the survival observed for starved larvae at the end of the experimental period (Age 19–29 days). By age 22 days, replicates for AQF1/Slow and AQF1/Fast were each pooled due to low survival within each replicate. Error bars represent standard error.
Fig 5.
Mean shell length over time for each line by cohort grouping in fed controls and starved treatment.
Culture from days 3–7 post fertilization occurred in 200-L larval tanks (prior to starvation) and size-based experiments in 20-L tanks. Shell lengths for fed controls after age 14 days and starved treatments after age 22 days should be interpreted with caution because settlement of large individuals out of the larval pool may have biased the size distribution. Arrows indicate days in which settlement was clearly observed in each treatment. Age 7–17 days represent the period of starvation, indicated by the blue box on the x-axis. Error bars represent standard error. Due to low survival in the AQF1 cohorts, length measurements were not possible after age 14 and 22 days for fast and slow growers, respectively. Additionally, from age 17 to 22 days in the AQF1/Slow cohort only one replicate of length measurements was possible.
Table 1.
Growth rate (μm/day ± SE) during the linear growth phase for fed (age 10–17 days) and starved-recovering (age 22–29 days) larvae.
AQF1 starved cohorts were not included in the statistical analysis due to high mortality and a lack of replication (one pooled replicate per cohort) during the recovery period. Superscript letters indicate significant differences between cohorts within each treatment and asterisks (*) indicate significance between treatments within each cohort (Tukey’s HSD p < 0.05).
Fig 6.
Respiration rates of all cohorts measured at the end of the starvation exposure (T = 10; Age 17 days), and during recovery at 5- and 8-days post reintroduction of food (Age 22 and 25 days, respectively).
The number of replicates per time point for each cohort is indicated above each bar. Error bars represent standard error.