Genetic and morphological variation of metacercariae of Microphallus piriformes (Trematoda, Microphallidae): Effects of paraxenia and geographic location

• Published in: International Journal for Parasitology: Parasites and Wildlife
• Main Authors: Egor A. Repkin, Arina L. Maltseva, Marina A. Varfolomeeva, Roman V. Aianka, Natalia A. Mikhailova, Andrei I. Granovitch
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2020
• Subjects: Zoology; QL1-991; Barents Sea; White Sea
• Online Access: https://doi.org/10.1016/j.ijppaw.2020.02.004; https://doaj.org/article/a89f2487c63d4bc5ae1c4b4c8c11a8f2

Host organism offers an environment for a parasite, and this environment is heterogenous within the host, variable among individual as well as between the hosts, and changing during the host's lifetime. This heterogeneity may act as a prerequisite for parasite species divergence. Intraspecific variability related to a certain type of heterogeneity may indicate an initial stage of speciation, and thus poses an evolutionary importance. Here we analyzed genetic and morphologic variation of trematode metacercariae of Microphallus piriformes (Trematoda, Microphallidae). Genetic variability of trematodes was assessed from sequences of cytochrome c oxidase subunit 1 (COI) and internal transcribed spacer region (ITS-1). Morphological variation of metacercarial body shape was for the first time analyzed using geometric morphometrics. Parasites from the White Sea and the Barents Sea coasts demonstrated partial genetic divergence (according to COI sequence analysis) and had significantly different body shape. Neither genetic nor morphological variation of metacercariae was related to intermediate host species. We discuss possible causes of the observed genetic divergence of parasite populations in different geographic regions. Keywords: Microphallus piriformes, Trematoda, Paraxenia, Molecular markers, Geometric morphometrics, Developmental stability