Description
Species interactions, together with environmental conditions, regulate the structure and function of our natural world; yet these interactions are both temporally and spatially context-dependent. Changes in the strength or direction of species interactions have the capability of fundamentally altering ecological communities and food webs. Within the Chesapeake Bay, Panopeid mud crabs occupy an important node in the Bay’s food web, connecting low-level primary consumers and larger secondary and tertiary consumers. However, parasites can modulate host behavior and diets with the potential to form distinct trophic niches and significantly alter energy flow within a food web. The castrating barnacle, Loxothylacus panopaei, induces morphological and behavioral modifications of their host, likely altering the trophic niche of infected crabs. Here, we quantified the impact of the crab-castrating parasite (L. panopaei) on the trophic niche of mud crabs (Panopeidae) within the Hampton River, a temperate, urban tributary of the Chesapeake Bay. We sampled from September through November 2025 using modified vexar cages filled with ~5L of sun-bleached disarticulated oyster shell. Cages were suspended from a pier, and mud crabs were collected weekly. We quantified the trophic niche of healthy and infected crabs using stable isotopes (δ13 Carbon, δ15 Nitrogen, and δ34 Sulfur). We hypothesized that healthy and infected mud crabs occupied distinct trophic niche space. While we are awaiting our results, we expect to find further evidence of how parasites can modify major nodes within food webs. Parasites, while often inconspicuous, may fundamentally alter energy flow within and between ecosystems.