Baikal gastropods described by W.A. Lindholm

Abstract

The molluscan fauna of Lake Baikal is currently known to comprise about 150 species of gastropods, of which approximately 70% are endemics. Baikal gastropods include 8 families: Baicaliidae, Benedictiidae, Bithyniidae (Caenogastropoda), Valvatidae (Heterobranchia), Acroloxidae, Planorbidae, Lymnaeidae and Physidae (Panpulmonata). By studying the samples collected during a three-year expedition supervised by A.A. Korotneff, professor of the Kiev University, W.A. Lindholm described 55 new species, varieties (= subspecies) and forms (= morphs) that belonged to all families of gastropods (except Physidae) living in Baikal and in the connected shallow water bodies (sors). Lindholm was the first to note a wide spectrum of conchological variability of Baikal gastropods and their heterogeneous geographic distribution in the lake. Using collection of naturalist Petr Mikhno, Lindholm described two new species from Lake Hövsgöl (= Khubsugul) in Mongolia that has the hydrological connection to Lake Baikal via the Selenga River. Despite more than a century of studying the gastropod fauna in lakes Baikal and Hövsgöl, some species and subspecies described by Lindholm are rare, with only a few specimens subsequently being reported, and some have never been found again. The present study is a brief review of 46 species, subspecies and morphs of gastropods described by Lindholm. The review includes photographs of type specimens, main synonyms and references, detailed information on the type localities, diagnoses, and information on distribution in Baikal including depth zones and substrate types. All type specimens (except those of one species) are well preserved and are currently stored in the collection of the Zoological Institute of the Russian Academy of Sciences (St. Petersburg).

Discordance of genetic diversification between deep‐ and shallow‐water species of Kobeltocochlea Lindholm, 1909 (Caenogastropoda: Truncatelloidea: Benedictiidae) endemic to Lake Baikal with the description of a new species, review of the genus, and notes on its origin

“…Kobeltocochlea olchonensis —Sitnikova, 1995: 78, Figure 9B; Sitnikova, 2019: 229, Figure 8C (photo of the lectotype, diagnosis, and distribution).…”

Morphological and Genetic Variability in Radix auricularia (Mollusca: Gastropoda: Lymnaeidae) of Lake Baikal, Siberia: The Story of an Unfinished Invasion into the Ancient Deepest Lake

“…We studied the type series of Limnaea (Gulnaria) auricularia var. intercisa Lindholm, 1909 kept in the malacological collection of the Zoological Institute, Russian Academy of Sciences (ZIN) in St. Petersburg (see [10] for details) as well as numerous samples of Radix auricularia of Siberia and adjacent countries (Kazakhstan, Mongolia), which are kept in ZIN and in the Laboratory of Macroecology and Biogeography of Invertebrates, St. Petersburg State University (LMBI). In total, more than 250 specimens of Radix and other lymnaeid species (see Supplementary Table S1) were studied in this research.…”

“…The primary taxonomic identification of collected snails was carried out by comparison with museum specimens and descriptions and illustrations of different Radix species available from the literature [10,15,[27][28][29]33]. Both shell and internal anatomy characteristics were used for identification.…”

“…Among these taxa, snails (Mollusca: Gastropoda) represent one of the most interesting cases. In total, around 150 species of gastropods belonging to 8 families are known in the fauna of Lake Baikal; nearly 70% of them are endemic [9][10][11]. It is an ancient malacofauna whose roots can be traced back to the Paleogene, if not the late Mesozoic [12][13][14], and, during its long history, some snail families formed flocks of endemic species and genera.…”