Dataset: E. depressus digestion time
Deployment: Griffen_lab

Eurypanopeus depressus were collected by hand from oyster reefs within the North Inlet Estuary (33°20’N, 79°10’W, Georgetown, South Carolina) 24 hours prior to experimentation. All oyster reefs were within 5 km of each other and no oyster reef was closer than 200 m to another sampled reef. Infected crabs were identified by the presence of parasite externae which signifies the parasite was mature. We only used infected crabs with a single mature externa to reduce any variation produced by multiple infections. Our sampling methods could not discern whether crabs were infected with the immature, internal phase of the parasite, so it is possible that some crabs categorized as “not infected” did have infections. We utilized male and female crabs in both infected and uninfected treatments because the effects of parasitic castration made distinguishing the sex of infected crabs difficult.  Scorched mussels, Brachidontes exustus, are an important prey item of E. depressus and were collected from the same reefs from which we sampled crabs. Crab carapace width and mussel length were measured to the nearest 0.5 mm using a Vernier caliper while weight was measured to the nearest 0.01 g with a top loading balance AEP-2500G.

Crabs were starved 24 hours prior to experimentation to ensure empty guts and were monitored for 24 hours after the experiment to ensure none underwent ecdysis or extruded eggs. During the starvation period, crabs were held in filtered seawater (salinity 32–34, temperature 24.3 ± 0.8 °C, 1 µm filter) to prevent crabs from feeding on suspended particles. After starvation, crabs were placed in individual cylindrical glass containers (height 5 cm, radius 3 cm) filled with seawater, and allowed to acclimate for 5 minutes. A crushed mussel (shell length = 4 – 7 mm) was then placed in the center of the container. We continuously observed the crabs for one hour to determine when mussel consumption began and ended. Post one hour, crabs were checked every 10 minutes until they produced feces. Each trial had five infected and uninfected crabs with six trials run over six consecutive days (n = 30 for each treatment). Gut passage time was calculated as the time from initial food consumption to the time the crab first produced feces.