Shchenkov S.V.1*, Denisova S.A.1, Gorodilova E.Yu.2, Sokolov S.G.3 2025. First record of the cestode Trilocularia acanthiaevulgaris (Phyllobothriidea) in the piked dogfish Squalus acanthias (Elasmobranchii: Squaliformes) from the White Sea: morphological and molecular evidence // Invert. Zool. Vol.22. No.4. P.565–574 [in English].
1 Department of Invertebrate Zoology, St. Petersburg State University, Universitetskaja emb., 7/9, St. Petersburg 199034 Russia.
2 Research Resource Center for Molecular and Cell Technologies, St. Petersburg State University, Botanicheskaya Str., 17, St. Petersburg 198504 Russia.
3 A.N. Severtsov Institute of Ecology and Evolution RAS, Leninsky Prospect, 33, Moscow 119071 Russia.
* Correspondence author
Sergei V. Shchenkov: svshchenkov@yandex.ru https://orcid.org/0000-0002-0579-1660
Sofia Denisova: sofia.denisova1608@gmail.com https://orcid.org/0000-0002-5602-5894
Elizaveta Gorodilova: elizaveta.gorodilova@spbu.ru https://orcid.org/0000-0002-7891-7826
Sergey Sokolov: sokolovsg@mail.ru https://orcid.org/0000-0002-4822-966X
doi: 10.15298/invertzool.22.4.04
ABSTRACT: The piked dogfish Squalus acanthias is a pelagic shark rarely found in the White Sea, where its biology and parasitic fauna remain largely unexplored. This study presents the first documented record of the hyperapolytic cestode Trilocularia acanthiaevulgaris in the White Sea population of piked dogfish. A detailed morphological description of free proglottids is provided, including novel data on their surface morphology based on the distribution and structure of microtriches. Phylogenetic analysis of SSU and LSU rDNA sequences confirmed the species identity of the cestode, showing a close affinity with previously described T. acanthiaevulgaris isolate. These findings expand current knowledge on shark cestode diversity in the White Sea and emphasize the need for further research on elasmobranch parasites in this geographic region.
KEY WORDS: tapeworms, elasmobranchs, SEM, SSU, LSU, phylogeny.