Calcium Ions Effect on Planaria Feeding Behavior

Calcium is important for the contraction of muscles, neurotransmission, and signaling in animals. Like other active movers, invertebrate planarian flatworms have musculature for motility. Therefore, it can be inferred that without the proper concentration of calcium ions in the water they can’t undulate or extend the pharynx, a muscular feeding structure. Planaria are generally cultured at a 0.5 g/L concentration of instant ocean sea salt (IOS), which contains calcium ion of 0.126 mM. However, there is uncertainty in the concentrations of important ions, such as calcium, which are optimal for the maintenance and homeostasis of the planaria. Previous research on water quality and planarian behavior has focused on species Schmidtea mediterranea, Dugesia japonica, and Girardia guanjuatiensis, but not Girardia dorotocephala (G. dorotocephala), the species currently cultured at Lynn University. Because other than being just readily available these species of worms haven’t undergone research in the frame of calcium ions. G. dorotocephala may require different concentrations of calcium ions than those of other relative species, an analysis of their requirements is warranted. For this experiment, we plan to specify which concentration of calcium is required for G. dorotocephala cultures. We hypothesize that G. dorotocephala requires micronutrient concentrations differing from standard IOS water, as has been observed for other species of planaria. We base this hypothesis on our observations of their feeding behavior following starvation. To conduct this experiment, we plan to assay food localization behavior under different concentrations of calcium.