Towards disentangling the classification of freshwater fish trypanosomes

Zhang, Peng; Liu, Jie; Yin, Xiao-Ming; Zhou, Jun-Yu; Lukeš, Julius; Lun, Zhao-Rong; Lai, De-Hua

Abstract

Currently, new species of freshwater fish trypanosomes, which are economically important parasites, are being described based on subjectively selected features, i.e., their cell morphology and the host species. We have performed detailed phylogenetic and haplotype diversity analyses of all 18S rRNA genes available for freshwater fish trypanosomes, including the newly obtained sequences of Trypanosoma carassii and Trypanosoma danilewskyi. Based on a sequence similarity of 99.5%, we divide these trypanosomes into 15 operational taxonomic units, and propose three nominal scenarios for distinguishing T. carassii and other aquatic trypanosomes. We find evidences for the existence of a low number of freshwater fish trypanosomes, with T. carassii having the widest geographic and host ranges. Our analyses support the existence of an umbrella complex composed of T. carassii and two sister species.

• Journal Article Type: Article
• Acceptance Date: Jul 15, 2023
• Online Publication Date: Oct 13, 2023
• Publication Date: Nov 1, 2023
• Deposit Date: Dec 6, 2023
• Publicly Available Date: Dec 6, 2023
• Journal: Marine Life Science & Technology
• Print ISSN: 2096-6490
• Electronic ISSN: 2662-1746
• Publisher: Springer
• Peer Reviewed: Peer Reviewed
• Volume: 5
• Issue: 4
• Pages: 551-563
• DOI: https://doi.org/10.1007/s42995-023-00191-0
• Keywords: 18S rRNA, Freshwater fish trypanosomes, Phylogeny, Morphology