Hindupisidium Vinarski & Bespalaya, 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 : 330

Genus Hindupisidium Vinarski & Bespalaya gen. nov.

Zoobank number: urn:lsid:zoobank.org:act:6569B137-B63E-43D8-8878-621B085A9CF7 .

Type species: Pisidium clarkeanum G. Nevill & H. Nevill, 1871 .

Diagnosis: The maximum shell length is 3.6 mm. Shell triangular, moderately convex; the beaks are prominent, relatively narrow and markedly shifted posteriorly. Only one (exhalant) siphon present. The inhalant water current enters via the pedal slit. The outer demibranch is completely reduced or represent a very small outer demibranch. Both states of this character were also observed in Afropisidium kenianum from South Africa ( Korniushin and Glaubrecht 2002). However, according to Clewing et al. (2022), this species is a member of the genus Euglesa (see below).

Reproductive biology: The members of this genus are characterized as synchronous brooders (embryos are developing within a distinct brood sac).

Etymology: The genus name is derived from Hindustan, the Persian name for India, where its type species is distributed.

Distribution: The genus includes at least three valid species ( Table 1 ), whose ranges cover India, Myanmar, Vietnam, and Nepal ( Fig. 3E ).

Remark: Although P. pirothi represents the type species of Afropisidium , according to Clewing et al. (2022), all African species, including P. ethiopicum (Supporting Information, Fig. S2H ), P. cf. kenianum , P. ovampicum , and P. cf. pirothi , cluster within the Euglesa clade, and none of these taxa is found within the Afropisidium clade. In this case, the name Afropisidium cannot be applied to the clade, containing Pisidium nevillianum ( Figs 5B , 6B , and 7B ), Pisidium javanum (van Benthem Jutting, 1931) , and Pisidium clarkeanum (Nevill & Nevill, 1871) , and, thus, we erected here a new genus to include these species formely classified within Afropisidium .

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 5. Representatives of valid genera in the subfamily Sphaeriinae:(A) Euglesa casertana, Russia, Yamalo-Nenets Autonomus Okrug, Gydan Peninsula; (B) Hindupisidium nevillianum (Myanmar, Inle Lake); (C) Conventus conventus, Russia (Arkhangelsk Region, Novaya Zemlya); (D) Pisidium amnicum (Russia, Nenets Autonomus Okrug, Vashutkiny Lakes); (E) Sphaerium corneum (Russia, Arkhangelsk Region, Bolshoy Solovetsky Island); (F) Sphaerium lacustre (Russia, Irkutsk Region, Angara River). Photos:O.V.Aksenova. Scale bar: 1 mm.

Figure 6. Teeth morphology and shell pores of representatives of the genera in the subfamily Sphaeriinae: (A) Euglesa casertana (Russia, Yamalo-Nenets Autonomus Okrug, Yamal Peninsula); (B) Hindupisidium nevillianum (Myanmar, Inle Lake); (C) Conventus conventus (Russia, Arkhangelsk Region, Novaya Zemlya); (D) Pisidium amnicum (Russia, Nenets Autonomus Okrug, Vashutkiny Lakes); (E) Sphaerium corneum (Russia, Arkhangelsk Region, Bolshoy Solovetsky Island).Photos: O.V. Aksenova.Scale bars: teeth—0.5 mm; pores—20 µm. The left-hand, central column—right and left valves, respectively; the right-hand column—pores.

Figure 7. Anatomy of siphons and gills of representatives of the genera in the subfamily Sphaeriinae: (A) Euglesa casertana (Russia, Vaigach Island); (B) siphon of Hindupisidium nevillianum (Myanmar, Inle Lake); (C) siphon of Conventus conventus (Russia, Arkhangelsk Region, Novaya Zemlya); (D) siphon of Pisidium amnicum (Russia, Tyumen Region); (E) siphon of Sphaerium corneum (Russia, Arkhangelsk Region, Bolshoy Solovetsky Island); (F) siphon of Sphaerium lacustre (Russia, Irkutsk Region, Angara River); (G) gill with embryos of E. casertana (Russia, Vaigach Island); (H) gills with embryos of P.amnicum (Russia, Nenets Autonomus Okrug, Vashutkiny Lakes); (I) gills with embryos of S. lacustre (Russia, Irkutsk Region, Angara River). Photos:O.V.Aksenova. Scale bars: 0.5 mm.