Marine Ectoparasite Communities on Batoid Hosts

Lydia Hughes (1, 2), Nancy Smith (1), William Szelistowski (1)

(1) Eckerd College Marine Science, (2) Florida Fish and Wildlife Conservation Comission

Stingrays are common hosts to a variety of marine ectoparasites, yet studies investigating these parasites at the community level are rare. We surveyed Atlantic (Hypanus sabinus) and Bluntnose (Hypanus say) stingrays in Tampa Bay from August to November 2025 to characterise and compare their ectoparasite communities. 66.7% of H. sabinus were parasitized by branchiurans (Argulus flavescens), copepods (Caligus sp. and Lepeophtheirus sp.), jawless leeches (Branchellion ravenelii), and capsalid monogeneans (Listrocephalos corona). Hypanus say experienced lower prevalence (13.8%) and were infected by Argulus flavescens, Caligus sp., Lepeophtheirus sp., Branchellion ravenelii, and monocotylean monogeneans (Monocotyle sp.). Ectoparasites consistently preferred ventral sites, parasitizing 37.9% of rays’ ventral surfaces (n = 137 parasites), compared to 24.1% on the dorsal surface (n = 28 parasites). Parasite load was positively correlated with disc width for both species of stingrays. Additionally, parasite prevalence and load were higher for Bluntnose stingrays captured from inner versus outer Tampa Bay. Further, Atlantic stingrays experienced higher infections in muddy than in sandy habitats. We also compared Tampa Bay Atlantic stingrays with individuals from St. Mark’s National Wildlife Refuge, and found the St. Mark’s population experienced higher prevalence and load than those in Tampa Bay, but lower species richness. Differences in parasite prevalence and load across ray species, locations, and habitats indicate that host lifestyle and environment greatly influence ectoparasitic infections. This study provides a baseline for the relationships between host habitat use and parasitism, which is important in understanding transmission dynamics and elasmobranch conservation.