Alekseev V.R. 2025. Revision of the systematic position of Eucyclops bathanalicola Boxshall et Strong, 2004, with the description of Boxshallianus gen.n. and Boxshallianidae fam.n. // Invert. Zool. Vol.22. No.4. P.631–642 [in English].
Zoological Institute of Russian Academy of Sciences, Universitetskaya emb., 1, Saint Petersburg 199034 Russia.
Victor Alekseev: alekseev@zin.ru https://orcid.org/0000-0002-1968-2609
doi: 10.15298/invertzool.22.4.08
ABSTRACT: As part of a global revision of the genus Eucyclops Claus, 1895, Eucyclops bathanalicola Boxshall et Strong, 2004, discovered in the mantle cavity of a gastropod mollusk from Lake Tanganyika (Central Africa), was studied. This finding represents the first documented case of a copepod ectoparasite on an invertebrate host in continental waters. Significant morphological transformations in the antennal and oral appendages of the cephalosome in E. bathanalicola do not correspond with the diagnostic characteristics of the family Cyclopidae. The classification of this species within the genus Eucyclops, as proposed by the authors, obscures the taxonomic boundaries of higher systematic units. A cladistic analysis of key morphological traits separates this taxon from representatives of all families within the modern suborder Cyclopida. Based on these findings, a new monotypic genus, Boxshallianus gen.n., and a new family, Boxshallianidae fam.n., were established. The single species from Lake Tanganyika was assigned a new name, Boxshallianus bathanalicola (Boxshall et Strong, 2004) stat.n. A critical feature for the new family is the transformation of the maxilliped from a grasping organ into an unarmed, single-segmented plate (an organ of attachment). The study also discusses the necessity of revising the current systematics of cyclopid copepods.
KEY WORDS: Eucyclops, Boxshallianus, Boxshallianidae, Cyclopida, Cyclopidae, fresh water, parasitic copepods, ectosymbiont, invertebrate host, Lake Tanganyika, taxonomy, status change.