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Abstract HysteromorphaLutz, 1931 is a small but broadly distributed genus of diplostomoidean digeneans parasitic as adults primarily in cormorants, but also reported from some other fish-eating birds. Their metacercariae were found in a variety of freshwater fishes as second intermediate hosts. Prior to this study, the genus included only 3 nominal species, 2 of them distributed in the Old World and 1 in the New World. We obtained sequences of partial mitochondrialcox1 gene and nuclear rDNA operon from new specimens collected in Europe, North and South America and used them for species comparisons and phylogenetic analysis. We also examined morphology of our newly collected specimens as well as museum specimens. Our analysis has demonstrated that at least 2 (likely 3) species ofHysteromorphaare distributed in the Americas.Hysteromorphasp. previously sequenced from larval stages, clearly represents a new species named hereinHysteromorpha ostrowskiaen. sp.Achatz, Locke et Tkach. Morphology of adults of the new species was earlier described in sufficient detail under the nameHysteromorpha triloba(Rudolphi, 1819). Our analyses also suggest the presence of another unknownHysteromorphasp. in North America represented bycox1 sequence from southeastern Canada (GenBank JF769473), but no morphological vouchers are available for this species.
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First integrative study of the diversity and specificity of metacercariae of Posthodiplostomum Dubois, 1936 from native and introduced fishes in the Caribbean
Abstract Metacercariae of the genus Posthodiplostomum are often recorded in freshwater fish hosts. While the diversity and taxonomy of this genus are receiving increasing attention in molecular phylogenetic studies, available data remain geographically biased. Most molecular studies of Posthodiplostomum and morphologically similar (neascus) worms originate in North America and Europe and Asia (more than 60% of DNA sequences are from USA and Canada), with few data currently available from the Neotropics, where high host diversity suggests high and under-sampled parasite diversity. In this study, we report molecular and morphological data from metacercariae of Posthodiplostomum in fish in Puerto Rico, where only a single species has been previously reported. Partial sequences of cytochrome c oxidase subunit 1 from metacercariae from Dajaus monticola (native to Puerto Rico) and the introduced fishes Poecilia reticulata , Parachromis managuensis , Lepomis macrochirus and Micropterus salmoides revealed 7 genetically distinct species-level lineages, of which 4 were novel. We report novel molecular life-cycle linkages in Posthodiplostomum macrocotyle (metacercariae in muscle of the cichlid Pa. managuensis ), a species previously known only from adults in birds from South America; and in Posthodiplostomum sp. 23 (metacercariae in poeciliids), which has recently been found in Ardea herodias in Georgia, USA. We also report the first molecular data from Posthodiplostomum sp. 8 in M. salmoides in the Caribbean. Metacercariae of most species were morphologically distinguished and all displayed narrow specificity for fish hosts, with no indication of parasite sharing among introduced and native fishes.
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- Award ID(s):
- 1845021
- PAR ID:
- 10403937
- Date Published:
- Journal Name:
- Parasitology
- Volume:
- 149
- Issue:
- 14
- ISSN:
- 0031-1820
- Page Range / eLocation ID:
- 1894 to 1909
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1017/S0031182022001214
