The other species, E. And if E. In their study, published recently in Environmental Science and Technology , a team of researchers from UFZ, the AWI and the University of Irkutsk investigated how these two species of amphipods react to chemical pollution in the water. The animals were exposed to the heavy metal cadmium, which served as a model toxin. Although the water in Lake Baikal is still largely unpolluted, cadmium is a relatively frequent environmental pollutant whose toxicity makes it extremely problematic to ecosystems.
It seems likely that Lake Baikal could see increasing heavy metal pollution. The lake's largest tributary, the Selenga River, is increasingly polluted with mining waste water from Mongolia, and via air, pollutants reach the lake from the industrial region around Irkutsk.
The reactions of the amphipods were observed in the laboratory. This is a warning sign, because the animals might avoid feeding when this happens, do not reproduce and are more likely to fall prey to predators due to reduced activity. Even a low but constant level of chemical pollution in Lake Baikal could have massive impacts on individual species and the ecosystem as a whole.
In another study, the UFZ researchers together with bioinformatics experts from the University of Leipzig obtained the first insights into the genome of E. It is surprisingly large -- about three times the size of the human genome. The genome data will be used as the basis for further investigation of physiological adaptation strategies in different environmental conditions.
According to Luckenbach: "We want to shed a little more light on this area, understand the physiological level even better and find out whether there are other mechanisms that enable the organisms to withstand the effects of climate change and exposure to pollutants, because ultimately we want to be able to predict how the ecosystem might change. Note: Content may be edited for style and length. Science News.
Bedulina, Denis V.
- ISBN 13: 9789057820014?
- Senior Collaborators.
- Lake Baikal: World's Largest, Deepest Lake.
- Armageddon (Dreamland, Book 6).
- Lake Baikal: Evolution and Biodiversity.
- Lake Baikal – Evolution and Biodiversity?
- Lake Baikal: World's Largest, Deepest Lake | Live Science.
Shatilina, Yulia A. Lubyaga, Ekaterina V. Madyarova, Anton N. Gurkov, Maxim A. Timofeyev, Hans-O. Sartoris, Rolf Altenburger, Till Luckenbach. Axenov-Gribanov, Anton N.
Gurkov, Michael Ginzburg, Daria S. Cyphocottus and Cottocomephorus are near-endemic. Around 30 species are endemic. Taxonomic revisions suggest that two subspecies Thymallus arcticus baicalensis and Thymallus arcticus brevipinnis within the Thymallidae family should in fact be two distinct species inhabiting the Baikal basin and other parts of the Yenisei drainage.
Artificial breeding is currently being conducted. In Lake Baikal it forms three races: pelagic, coastal, and near-bottom deepwater. Which area it inhabits is characterized by locations of breeding and feeding migrations and characteristic features of growth and feeding. For reproduction it migrates to tributaries of the lake.
The pelagic race reproduces primarily in the Selenga River during two peaks of spawning migration in September and October. The coastal race spawns mostly in tributaries of northern Baikal, Verkhnyaya Angara, and Kichera, and also in the Barguzin River. Lake Baikal is inhabited by unique endemic flora and fauna.
The biological diversity of plants and animals inhabiting Baikal is greater than other lakes of the world. The number of known species and subspecies is more than two times greater than in Lake Tanganyika, which is second in species and subspecies diversity.
At present approximately species of animals and more than species of plants inhabit Lake Baikal. However, the given number of species is not final. Fifteen to 20 new taxa of different ranks are described annually. The estimated total number of animal species in a lake may be , and of plant species, The ecosystem of Lake Baikal is close to ocean ecosystems in structure and other characteristics. Characteristic features include:.
Lake Baikal: Protection of a unique ecosystem
Presence of a pelagic community of organisms, characterized by low species diversity and high productivity. The basis of abundance and biomass of mesoplankton up to 0. Pelagial ichthyocenosis is comprised of secondary pelagic viviparous fishes, Comephorus baikalensis and C. Other near-bottom pelagic sculpins include Baikal yellowfin Cottocomephorus grewingkii and longfin Baikal sculpin C. The presence of zones of high productivity of macroplankton in the near slope area above depths of several hundred meters , analogous to highly productive upwellings in oceans.
Molecular and morphological evolution of the amphipod radiation of Lake Baikal. - Semantic Scholar
The benthic community is characterized by extraordinary species diversity and high productivity up to 30 g m -2 in open littoral and up to 80 g m -2 in bays , consisting mostly of oligochaetes, mollusks, amphipods, and chironomids. Presence at great depths more than m of freshwater deepwater fauna; its analogues are only known in seas and oceans.
The benthic cottoids are divided into three bathymetric groups: 1 coastal shallow water species in depths up to m; including species from the genera Leocottus, Paracottus, Batrachocottus, and Procottus ; 2 eurybathic species that inhabit a wide range of depths between m during their lifespan; including species from the genera Asprocottus, Cyphocottus, Limnocottus, Batrachocottus ; 3 deepwater abyssal species that are restricted to depths from to m; including Abyssocottus, Cottinella, Neocottus.
It is peculiar that the peak of species diversity in Lake Baikal has shifted to greater depths. There are questions regarding when the ancestral forms of Cottoidei invaded Lake Baikal, as well as the evolution of their modern diversity. According to the theory proposed by Berg Sideleva , these fishes have ancient freshwater routes and are autochthonous.
Another theory proposed by Dorogostaisky, and developed in detail by Taliev , emphasizes the young evolutionary age of this group and intensity of speciation within it. Recent molecular genetic studies Slobodyanyuk et al. Thus, the evolution of the cottoid fishes in Lake Baikal is an example of explosive radiation and extremely high rates of morphological and ecological diversification.
By the numbers
Taliev and Bazikalova considered fetalization to be the main factor of speciation. According to these authors, fetalization is an occurrence of primitive and juvenile characteristics in species that improves specific plasticity, abilities for evolutionary transformations, and adaptations for changing environmental conditions. Taliev supposed fetalization to be a qualitative leap that begins a new stage of evolution. Among other important factors contributing to speciation, Taliev mentioned abrupt tectonic tranformations of the lake hollow that led to changes in the habitats of fishes.
Kozhov , discussing questions of the origin and evolution of the Baikal endemic fauna, considered the high depths, formation of abyssal fauna, and filling of different ecological niches to be the main causes of speciation in the lake. Mednikov explained the evolution of Baikal cottoids as sympatric speciation based upon the formation of infraspecific groups of individuals populations with different modes of life; a biotopical isolation of populations and then an appearance of reproductive isolation.
In spite of some dissent among investigators regarding the age and causes of speciation of Baikal fauna, a common idea is that the fauna is autochthonously formed, meaning that the entire diversity of endemics evolved in Lake Baikal itself.