Abstract

The blowhole is an anatomic structure unique to cetaceans and its microbiome has previously been proposed as a potential biomarker of cetacean health.¹ Despite its potential importance to cetacean health and physiology, the blowhole microbiome has been minimally studied, and its constituents in clinically healthy individuals have not been consistently characterized. While flagellates and ciliates have been isolated from blowhole samples, research has predominantly focused on bacterial communities, limiting our understanding of the clinical significance of protozoa within the cetacean microbiota.^1-3 This study aimed to (1) characterize a flagellate that was cytologically recognized in the blowhole of two bottlenose dolphins (Tursiops truncatus) using PCR and to (2) investigate the clinical significance in these two dolphins. PCR analysis revealed that the isolated flagellate was a novel species within the subclass Metakinetoplastina. Over the course of monitoring for two years, the flagellates were observed in variable numbers cytologically, and neither cytologic abnormalities related to the organism, nor evidence of clinical illness, were found in either dolphin. The findings support previous reports of commensal behavior in related kinetoplastids, suggesting this new flagellate species likely maintains a non-pathogenic ecological interaction with its host.^2,4-6 This research enhances our understanding of host–microorganism dynamics in cetaceans and identifies a flagellate of the subclass Metakinetoplastina that can be observed in upper respiratory tract cytology samples of clinically normal bottlenose dolphins.

Acknowledgements

The authors wish to thank the staff of Dolphins Plus, Key Largo, FL, and the University of Florida Zoological Medicine Diagnostic Laboratory, Gainesville, FL, for their contributions to this study.

*Presenting author
+Student presenter

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