Spatial Distribution of Eudactylina sp. (Copepoda: Siphonostomatoida: Eudactylinidae) Infecting Gill of Angel Sharks (Squatina sp.) Captured in the Northeastern Gulf of Mexico

Abstract

Parasite spatial distribution studies shed light on host-parasite relationships especially in regards to host and site specificity. This is especially true for parasitic copepods that infect demersal fishes. The objective of this study was to examine the relationship between the angel shark, Squatina sp. within the Gulf of Mexico and an unnamed species of parasitic copepod (Eudactlyina sp.) that infects its gills. Infection prevalence was 88.5% and the population of copepods is overdispersed (aggregated) in its host and not uniformly distributed between male and female sharks. Copepods were found to infect particular hemibranchs and exhibited regional attachment across horizontal and longitudinal positions on hemibranchs and across vertical positions of the gill lamellae. Additionally, copepods were attached perpendicular to or facing water flow. The number of eggs per copepod was similar across all attachment regions and hemibranch positions. In summary, my results indicate a high level of microhabitat site specificity by copepods and copepod orientation relative to respiratory water flow is similar to that reported for other parasitic copepods inhabiting? sharks.