Euglesa moroccana Bespalaya, Vinarski, Aksenova, Mabrouki, 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 : 328-329

Euglesa moroccana Bespalaya, Vinarski, Aksenova, Mabrouki, Kondakov & Palatov sp. nov. ( Fig. 11C )

Zoobank number: urn:lsid:zoobank.org:act:6489DC98-2554-42FF-A046-D48B8A7E320E .

Type series: The holotype and 19 paratypes are deposited in RMBH (accession numbers: Sph-771, 775) .

Type locality: Africa , Morocco, Fès-Meknès region, Ain Chkef spring .

Etymology: This species is named after the country where the holotype was collected.

Material examined: Africa , Morocco, Tafoughalt stream, 13.IV.2021, Mabrouki leg., three specimens (lot no. RMBH MSph-771); Morocco, Ain Chkef spring, 14.III.2021, Mabrouki leg., 16 specimens (lot no. RMBH MSph-775), Abkhazia, Gudauta District, spring on the shore of the lake near the station Psyrtskha, 09.II.2018, Palatov leg., two specimens (lot no. RMBH MSph-327/2) .

Description: The shell length is 3.4 mm, round-oval in shape ( Fig. 11C ). The beaks are rounded, not prominent, offset to the posterior edge of the valves ( Fig. 11C ). The cardinal tooth of the right valve is curved and thickened on the posterior end. The outer cardinal tooth of the left valve is slightly curved, reaches half of the inner cardinal tooth; the inner cardinal tooth of the left valve is curved ( Fig. 12D ).

Distribution: Africa, Southern Europe, and Western Asia.

Comment: The 16S and 28S rRNA sequences of this species have no analogues in GenBank and are closest to the E. subtruncata group ( Fig. 2 ). We analysed the original descriptions of some species of this group: Euglesa pallida ( Gassies, 1855) , Euglesa altaica (Krivosheina, 1979) , Euglesa arcidens Krivosheina, 1978 , Euglesa humiliumbo Krivosheina, 1978 , Euglesa ovatotrigona (Krivosheina, 1979) , Euglesa parallelodon Krivosheina, 1978 , Euglesa rotundotrigona Krivosheina, 1978 , Euglesa starobogatovi Krivosheina, 1978 , Euglesa subcuneata Krivosheina, 1978 , Euglesa tenuicardo Krivosheina, 1978 , Euglesa turanica (Clessin in Martens, 1874) (Supporting Information, Fig. S3 ). In addition, the type specimens (paratypes) of Pisidium ethiopicum Korniushin, 1995 and all the listed species described by Krivosheina (1978) from the ZIN collections were studied (Supporting Information, Fig. S2H ). Morphological descriptions of these species did not correspond to those of our specimens. It should be noted that E. moroccana was also found in Macedonia, Iran, and Turkey but the authors of these records could not identify them and designated this species as Pisidium cf. casertana or Pisidium casertana (GenBank accession numbers KF483299, KF483316, KF483293) ( Clewing et al. 2013).

Differential diagnosis: Euglesa moroccana can be distinguished from its sister species E. zugmayeri and E. kyrgyzica by having a specific morphology of the cardinal teeth ( Fig. 11C ). The cardinal teeth of the left valve of E. zugmayeri are slightly curved, are of the same length, and almost parallel to each other, whereas the cardinal teeth of E. moroccana have different lengths and are not parallel to each other (see description above). As for the differences of the new species from E. kyrgyzica , see the differential diagnosis for the latter species above.

Molecular diagnosis: The uncorrected 16S p-distance of the new species from other congeners is 1.1–10.3% and that based on 28S rRNA is 0–4.8% (± SD). The nearest congener is E. kyrgyzica with the mean uncorrected 16S p-distance 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 3. Maps of approximate geographic distribution of six genera of the Sphaeriinae in the world based on available 16S rRNA sequences: (A) Sphaerium; (B) Euglesa; (C) Pisidium s.s.; (D) Odhneripisiduim; (E) Hindupisidium; (F) Conventus.

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.