Testing Protocols for Surveying Captive Limulus polyphemus Microbiomes

Limulus polyphemus, the Atlantic horseshoe crab, is a marine arthropod that primarily resides in the shallow intertidal zone of brackish water, water where high salinity seawater meets fresh water. The ecological niche that horseshoe crabs reside in makes them an ideal animal to be placed in an aquarium touch-tank, only needing a shallow pool of water to live comfortably as well as having a tough chitin carapace that won’t be easily damaged by visitors touching them. However, the implications of these human-animal interactions are severely unexplored with limited research being conducted regarding touch-tanks. In contrast, the consequences and hygienic practices of human-animal interactions for vertebrates in petting zoos is very well understood. In this study, we attempted to lay the groundwork for future research that will aspire to do a more thorough analysis of what microbes reside in aquarium touch tanks and how those microbes could affect both the animals and the people touching them. The efficiency of a potential DNA sequencing protocol is tested in this study; horseshoe crabs residing in the touch-tank exhibit in the Shark Reef Aquarium had their carapace sampled for microbes with sterile swabs which transferred to agar plates in an attempt to isolate pure colonies. Four samples were successfully isolated from the initial sampling in pure cultures using the streak plate method. DNA extraction was successfully performed on all four samples using both SDS lysis buffer and a “DNeasy Blood & Tissue kit.” PCR is not known to have worked for any samples as of yet. Ultimately, it was decided that the low amount of unique species isolated along with lack of success with PCR suggests that an alternative method should be utilized for any further work