Two parasitic ciliates (Protozoa: Ciliophora: Phyllopharyngea) isolated from respiratory-mucus of an unhealthy beluga whale: characterization, phylogeny and an assessment of morphological adaptations

• Published in: Zoological Journal of the Linnean Society
• Main Authors: Jin, Didi, Qu, Zhishuai, Wei, Bojue, Montagnes, David J S, Fan, Xinpeng, Chen, Xiangrui
• Other Authors: National Natural Science Foundation of China, Technology Innovation Team of Ningbo
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press (OUP) 2020
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Beluga; Beluga whale; Beluga*
• Online Access: http://dx.doi.org/10.1093/zoolinnean/zlaa086; https://academic.oup.com/zoolinnean/article-pdf/191/4/941/49578322/zlaa086.pdf

Abstract Ciliates occur in the blowholes of marine mammals, but our understanding of their biology is poor. Consequently, we investigated an infestation of ciliates in an unhealthy, captive beluga whale that was exhibiting accelerated breathing, leukocytosis and expulsion of unusually large amounts of viscous sputum. This sputum contained ~104 ciliates mL-1 (when healthy, numbers were ten- to 100-fold lower). One known ciliate species, Planilamina ovata, is fully characterized, and a new species, Kyaroikeus paracetarius sp. nov., is here described. The new species is established based on its larger number of left kineties over its only congener. Sequences of small-subunit rDNA, large-subunit rDNA and ITS1-5.8S-ITS2 regions of these two taxa were used in phylogenetic analyses, inferring that Kyaroikeus and Planilamina have close affinity with the free-living family Dysteriidae, contradicting their morphology-based assignment to the family Kyaroikeidae. We suggest that Kyaroikeidae be relegated to subfamily status. Finally, by comparing parasitic species with free-living taxa, we suggest how these ciliates have adapted to their unique environment and how they may have initially invaded the host. We provide essential data and concepts for the continued evaluation of ciliate-parasites in whale blowholes.