New species Eutobrilus Gagarini sp. n. and a review of species of the genus Eutobrilus from graciliformis-group (Nematoda: Tobrilida, Tobrilidae, Eutobrilinae)

S.Ya. Tsalolikhin

Proceedings of the Zoological Institute RAS, 2022, 326(4): 303–308 · https://doi.org/10.31610/trudyzin/2022.326.4.303

Full text

Abstract

A new species of Eutobrilus gagarini sp. n. from the Leningrad region is described, which is included in the morphological graciliformis-group of the genus Eutobrilus and differs from other species of the group by a high coefficient "b" and a smaller ratio of the length of the spicules to the length of the supplementary row and the ratio of the length of the spicules to the length of the body. A key for determining the Holarctic species of the graciliformis-group is given and the composition and structure of this group as a whole are discussed. The expediency of isolating the morphological graciliformis-group is discussed. The synonymization of the genus Peritobrilus Gagarin, 1993 with the genus Eutobrilus Tsalolikhin, 1981 is confirmed.

Key words

new species, free-living freshwater nematodes, Eutobrilus gagarini Tsalolikhin sp. n., Tobrilidae

Submitted January 26, 2022 · Accepted October 18, 2022 · Published December 23, 2022

References

Altherr E. and Delamare Deboutteville C. 1972. Nématodes interstitiels des eaux douces des États-Unis d'Amérique (États de Washington, du Colorado et du Massachusetts) récoltés par Cl. Delamare Deboutteville. Annales de Spéléologie, 27: 683–760.

Gagarin V.G. 1993. Free-living nematodes in freshwaters of Russia and adjacent lands. Gidrometeoizdat, St. Petersburg, 352 p. [In Russian].

Gagarin V.G. 2009. To the revision of the genus Eutobrilus Tsalolikhin, 1981 (Nematoda, Triplonchida). Inland Water Biology, 3: 17–24. [In Russian]. https://doi.org/10.1134/S1995082909030031

Gagarin V.G. and Gusakov V.A. 1998. Two new species of free-living freshwater nematodes (Tobrilidae) from the Volga basin. Zoologicheskiy Zhurnal, 77: 1064–1067. [In Russian].

Naumova T.V. and Gagarin V.G. 2019. Review of the free-living Nematode (Nematoda) fauna of Lake Baikal. Zootaxa, 4608(1): 101–118. https://doi.org/10.11646/zootaxa.4608.1.5

Tsalolikhin S.Ya. 1983. Nematodes of families Tobrilidae and Tripylidae of world fauna. Nauka, Leningrad, 232 p. [In Russian].

Tsalolikhin S.Ya. 2001. Synopsis of the system of the family Tobrilidae (Nematoda: Enoplida). Russian Journal of Nematology, 9: 19–24.

Tsalolikhin S.Ya. 2005. A review of the genus Eutobrilus (Nematoda, Enoplida, Tobrilidae). Zoologicheskiy Zhurnal, 84: 915–921. [In Russian].