Euglesa kyrgyzica Bespalaya, Aksenova, Kondakov & Palatov, 2024

Bespalaya, Yulia V., Vinarski, Maxim V., Aksenova, Olga V., Babushkin, Evgeniy S., Gofarov, Mikhail Yu., Kondakov, Alexander V., Konopleva, Ekaterina S., Kropotin, Alexander V., Mabrouki, Youness, Ovchankova, Nadezda B., Palatov, Dmitry M., Sokolova, Svetlana E., Shevchenko, Alexander R., Travina, Oksana V., Taybi, Abdelkhaleq F., Soboleva, Alena A., Zubrii, Natalia A. & Bolotov, Ivan N., 2024, Phylogeny, taxonomy, and biogeography of the Sphaeriinae (Bivalvia: Sphaeriidae), Zoological Journal of the Linnean Society 201 (2), pp. 305-338 : 326-327

Euglesa kyrgyzica Bespalaya, Aksenova, Kondakov & Palatov sp. nov.

( Figs 11B and 12A, B ) Zoobank number: urn:lsid:zoobank.org:act:B9B03DA2-33D0-4C89-A928-44C3EAA887C5 .

Type series: The type series includes the holotype and 13 paratypes in RMBH (accession number: Sph-331) .

Type locality: Kyrgyzstan: Osh Region, Kara-Kulja District , springatKulunRiverBasin,protectedarea‘Mazar’ [40°30 ʹ 493″N 74°14 ʹ 265″E], 02.V.2017, Palatov leg., 15 specimens .

Etymology: This species is named after the country of Kyrgyzstan.

Material examined: The type series only.

Description: Shell round-oval in shape, its length is 3.4 mm (min– max 2.2–3.7 mm; Fig. 11B ). The beaks are rounded, slightly prominent, offset to the posterior edge of the valves ( Fig. 11B ). The cardinal tooth of the right valve is slightly curved, its posterior end is branched. The inner cardinal tooth of the left valve is thin, straight. The outer cardinal tooth of the left valve is curved and slightly S shaped ( Fig. 12A ).

Distribution: Kyrgyzstan.

Comment: The 16S and 28S rRNA sequences of this species have no analogues in GenBank but are more closely related to the E. subtruncata group ( Fig. 2 ). The analysis of morphological descriptions of nominal species included in this group did not reveal any correspondence with species found in Kyrgyzstan.

Differential diagnosis: Euglesa kyrgyzica can be distinguished from its sister species E. moroccana and E. zugmayeri (Weber, 1910) by morphology of the cardinal teeth ( Fig. 12A ). The outer cardinal tooth of the left valve of E. kyrgyzica is straight and the inner cardinal tooth is slightly S shaped unlike as those in related species. The cardinal tooth of the right valve of E. kyrgyzica is branched, whereas in E. moroccana and E. zugmayeri it is thickened on the posterior end.

Molecular diagnosis: The new species differs from its congeners by one fixed nucleotide substitution in the 16S rRNA gene fragment (12 G). The uncorrected 16S p-distances of the new species from other congeners are 1.1–8.3% and those based on 28S rRNA are 0–4.3%. The nearest congener is E. moroccana with the mean uncorrected 16S p-distance of 1.7 ± 0.5% (± SD).

Figures

Figure 2. The phylogeny of the subfamily Sphaeriinae recovered from ML analysis (W-IQ-TREE) and obtained for the complete dataset of mitochondrial and nuclear sequences (16S rRNA+28S rRNA). Black numbers near nodes are bootstrap support values (BS)/ Bayesian posterior probabilities (BPP). The new taxa are highlighted in red. Subgenera are marked by curly brackets.

Figure 11. New species of Sphaeriinae described in this paper: (A) holotype of Euglesa kolymensis (RMBH No. MSph-787, Russia, Yakutia); (B) holotype of E.kyrgyzyca (RMBH No. MSph-331, Kyrgyzstan); (C) holotype of E. moroccana (RMBH No.MSph-775, Morocco); (D) holotype of Odhneripisidium caucasus (RMBH No. MSph-296, Russia, Krasnodar Region); (E) paratype of O.caucasus (RMBH No. MSph- 327, Abkhazia).Photos: O.V. Aksenova.Scale bar:1 mm.

Figure 12. Morphology and anatomy of new Sphaeriinae species described in this paper (teeth morphology and shell pores, anatomy of gills and siphons): (A) holotype of E. kyrgyzyca (RMBH No. MSph-331, Kyrgyzstan); (B) paratype of E. kyrgyzyca (RMBH No.MSph-331, Kyrgyzstan); (C) holotype of E. kolymensis (RMBH No. MSph-787, Russia, Yakutia); (D) holotype of E. moroccana (RMBH No. MSph-775, Morocco); (E) paratype of Odhneripisidium сaucasus (RMBH No. MSph-327, Abkhazia).Photos: O.V. Aksenova. Scale bars:0.5 mm.