Gammarus lacustris G. O. Sars 1863

• Main Authors: Sidorov, Dmitry, Yalysheva, Elena, Sharyi-Ool, Mariana
• Format: Other/Unknown Material
• Language: unknown
• Published: 2021
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Malacostraca; Tanaidacea; Gammaridae; Gammarus; Gammarus lacustris; Indian; Tuva; Yenisey; Yakovlev; taiga; Siberia
• Online Access: https://zenodo.org/record/5572794; https://doi.org/10.5281/zenodo.5572794

Gammarus lacustris G.O. Sars, 1863 Gammarus lacustris G.O. Sars, 1863: 207 (original description). Gammarus pulex sibiricus – Kiseleva 1920: 15 (lakes of Ob’ basin). Gammarus pulex – Sars 1901: 133 (NE Mongolia); 1903: 233–261 (Siberia, Kazakhstan, Mongolia, Tibet). — Pirozhnikov 1929: 70 (Yenisey, upstream of Krasnoyarsk). — Lepneva 1930: 135 (around Biysk); 1933: 151 (Altay lakes). — Karaman 1991: 38 (see for full synonymy). Material examined (new records) RUSSIA – Tuva Republic • 3 ♀♀ (oostegites developed, some brooding the eggs), 15 ♂♂ (BL = up to 14.0 mm); small freshwater lake, southward of Shara-Nur Lake, near shepherd’s camp; 50°13′29.4″ N, 94°32′32.1″ E; 2–5 m depth; 12 Aug. 2011; E.N. Yalysheva leg.; yellowish silt, sapropelic mud with smell of hydrogen sulfide, plant residues (Phragmites australis); DAS 16-014 • 1 ♀ (BL = 17.0 mm); ‘ Dashtyg’ taiga lake, upper reaches of Yenisey (source of Dashtyg-Aryg Stream), Todzha; 53°25′12.2″ N, 96°51′52.7″ E; 0.5 m depth; 4 Aug. 2010; E.N. Yalysheva leg.; middle of lake, boulders, rubble, fouling, depressions between stones slightly silted; DAS 16-015. Remarks Considering the outstanding morphogenetic polymorphism (Sket et al. 2019) and the very wide distribution of Holarctic/Sino-Indian G. lacustris in the water bodies of Siberia (Tuva) and Mongolia (Fig. 1), it is highly probable that juveniles of this species can be misidentified as small species, such as G. koshovi. However, G. lacustris was absent in our samples from Tore-Khol, which we associated, first of all, with partial acidification of waters in the Russian part owing to the increased anthropogenic pressure because of intensive grazing, fishing, and other economic activities. It was previously reported that G. lacustris critically avoids water environments with pH <5 (Moiseenko & Yakovlev 1990). However, the exact reasons for this observation remain to be solved. Distribution and ecology Mostly inhabits the pluvial lakes of the region (Fig. 1), though it is also observed in lakes of the Baikal ...