Low annual temperature likely prevents the Holarctic amphipod Gammarus lacustris from invading Lake Baikal

Abstract

Species with effective thermal adaptation mechanisms allowing them to thrive within a wide temperature range can benefit from climatic changes as they can displace highly specialized species. Here, we studied the adaptive capabilities of the Baikal endemic amphipods Eulimnogammarus verrucosus (Gerstfeld, 1858) and Eulimnogammarus cyaneus (Dybowsky, 1874) compared to the potential Holarctic Baikal invader Gammarus lacustris Sars, 1863 at the cellular level including the energy metabolism and the antioxidant system. All species were long-term exposed to a range of temperatures (1.5 °C to mimic winter conditions and the three species-specific preferred temperatures (i.e., 6 °C for E. verrucosus, 12 °C for E. cyaneus and 15 °C for G. lacustris). At 1.5 °C, we found species-specific metabolic alterations (i.e., significantly reduced ATP content and lactate dehydrogenase activity) indicating limitations on the activity level in the Holarctic G. lacustris. Although the two Baikal endemic amphipod species largely differ in thermal tolerance, no such limitations were found at 1.5 °C. However, the cold-stenothermal Baikal endemic E. verrucosus showed changes indicating a higher involvement of anaerobic metabolism at 12 °C and 15 °C, while the metabolic responses of the more eurythermal Baikal endemic E. cyaneus may support aerobic metabolism and an active lifestyle at all exposure temperatures. Rising temperatures in summer may provide a competitive advantage for G. lacustris compared to the Baikal species but the inactive lifestyle in the cold is likely preventing G. lacustris from establishing a stable population in Lake Baikal.

Morphology and zoogeography of the burrower-like gammarid Gammarus koshovi (Bazikalova, 1946) (Crustacea, Amphipoda, Gammaridae) – An overlooked and poorly known species in the Siberian fauna

“…Mostly inhabits the pluvial lakes of the region (Fig. 1), though it is also observed in lakes of the Baikal Rift Zone (previous indications in Baikal are accidental, in Stom & Timofeev 1999; but see Vereshchagina et al 2021). Kamaltynov (2009) reported the following data: common at depths of 0-7 m, on pebbles with sand and detritus, silted sand, flooded woods, remains of vegetation, and abundant in aquatic plant thickets.…”

Different ways to play it cool: Transcriptomic analysis sheds light on different activity patterns of three amphipod species under long‐term cold exposure

“…cold adaptation, Eulimnogammarus cyaneus, Eulimnogammarus verrucosus, freshwater lake, Gammarus lacustris, Lake Baikal, transcriptome sequencing drastically reduced locomotor activity upon long-term cold exposure (Vereshchagina et al, 2021). Gammarus lacustris can be found inactive in leaf litter in winter and spring (own field observations).…”

“…Eulimnogammarus cyaneus is more thermotolerant than E. verrucosus and inhabits the upper littoral throughout the year. Field observations revealed that E. verrucosus and E. cyaneus maintain high locomotor activity at low temperatures (Vereshchagina et al, 2021) and E. verrucosus was found to reproduce during winter (Gavrilov, 1949). Gammarus lacustris has a slightly higher upper thermal limit than the Baikal endemic E. cyaneus.…”

“…verrucosus and E . cyaneus maintain high locomotor activity at low temperatures (Vereshchagina et al, 2021) and E . verrucosus was found to reproduce during winter (Gavrilov, 1949).…”

“…cyaneus . It is a cold‐resistant ectotherm of inland water ecosystems of the Holarctic that prepares for the cold season by the formation of cryoprotective biomolecules (Karanova & Andreev, 2010) and shows hypometabolism and consequently drastically reduced locomotor activity upon long‐term cold exposure (Vereshchagina et al, 2021). Gammarus lacustris can be found inactive in leaf litter in winter and spring (own field observations).…”