Dataset: P. herbstii diet & reproduction (Eco-Evo 2015)

We conducted a laboratory study in which we quantified consumption and reproductive effort. We collected 40 female mud crabs (Panopeus herbstii) in May from North Inlet. These were returned to the University of South Carolina in Columbia where they were placed into a recirculating aquarium held at 20°C on a 16 h:8 h light:dark cycle. Each crab was housed in an individual 1-L chamber, individually plumed to ensure constant flow at 3 L/h. Crabs were fed twice per week (Monday and Thursday) and were given 48 h to consume their food before uneaten food was removed. The food was dried for 72 h at 70°C, and weighed to the nearest 0.01 mg. Crabs were fed one of 20 experimental diets that varied the total amount of food present (0.3, 0.6, 1.2, 3% of body weight at each feeding) and the proportion of that food that was animal tissue or algae (0.0:1.0, 0.25:0.75, 0.5:0.5, 0.75:0.25, 1.0:0.0 animal:algal). Two crabs were fed each of these 20 experimental diets. However, food consumed could not be directly controlled (food offered served as an upper limit to consumption, but individual crabs could always choose to consume less on any given day). Each crab therefore had a different diet over the course of the experiment that reflected its aggregate daily diet decisions. We determined the average animal and algal consumption across feeding periods for each crab over the course of the experiment.  Algal food was Ulva lactuca, animal food was tilapia filets. This experiment continued as described above for 10 weeks, after which the crabs were dissected and ovaries, hepatopancreas, and the rest of the body were dried separately at 70°C for 72 h and were then weighed to the nearest 0.01 mg.