ARKHANGELSK, January 16. /TASS/. Scientists of the Federal Research Center for Complex Arctic Studies (the Russian Academy of Sciences' Urals Branch) for the first time studied complexly freshwater mollusks of the Kolguev Island in the Barents Sea. They found 13 species that are new to that territory, Olga Aksenova of the Russian Museum of Biodiversity Centers told TASS.
"The Kolguev is a small island in the Arctic. The only study of mollusks there was in 1895, when a British naturalist, Colonel Henry Wemyss Feilden, collected mollusk shells during a complex expedition. Later on, malacologist Edgar Smith described three species of gastropods, and one of them was described as a subspecies, which was new to researchers - L. ovata var. kolguevensis. No research has been conducted ever since. During our studies, we have found 13 species new to the island in addition to the three species, which the British researchers have discovered before us," the expert said.
In addition to gastropods and mollusks from families Lymnaeidae (Pond fish) and Planorbidae (Coils), the scientists have found small bivalve mollusks from the family Sphaeriidae, as well as representatives of the family Valvatidae (Valves). It was for the first time that valves were found on an Arctic island. "Experts have believed they can be found only on the mainland. These are interesting mollusks, their mouths are closed with lids, and thus they can tolerate unfavorable conditions," the researcher added.
In determining species, in addition to different shell shapes, experts use genetic analyses. Interestingly, the nucleotide sequences of the island inhabitants are identical or only slightly different from their relatives living in Siberia, the Far East and North America. Scientists find that mollusks have settled near the Kolguev relatively recently - after the retreat of glaciers. They could settle both by themselves in water systems, and with the help of waterfowl. The Kolguev is a well-known nesting place for many bird species. "We have identified one species among bivalves, which is a Siberian endemic. Its species status needs to be confirmed. We assume that it may be a species described earlier as Euglesa lindholmi. But our predecessors have made this description analyzing empty shells from river sediments in Siberia. Our samples are very similar to this species, so this is also an interesting discovery," said Yulia Bespalaya, director of the Center's Institute of Biogeography and Genetic Resources.
The experts have found that freshwater mollusks' fauna on the Kolguev is much richer than on the neighboring Vaygach Island or in Novaya Zemlya's south. In terms of the species numbers it is comparable to the Solovki, which are located much further to the south.
Why study mollusks
Mollusks play an important role in ecosystems. In the Arctic, ecosystems are generally depleted, and food chains are short, thus the loss of even one link can affect everyone. The Arctic lakes are known for valuable fish species that feed also mollusks. In addition, mollusks are active biology filters and are of great importance for self-purification of reservoirs.
During the studies, the Center's scientists were unable to detect two species of pond shells out of the three found back in 1895. "We know photos of those species, which are kept at natural history museums of Sweden and Great Britain, thus we do not doubt they exist. We, sure, would like to confirm genetically their taxonomic status," the expert explained. The researchers believe that most likely they do live on the island and hope to find them during another season. Besides, conditions in the reservoirs, where those samples were found more than 120 years ago, have changed. Due to the climate change, rivers and lakes on the island are becoming shallow and overgrown.
Scientists plan to continue the studies on the Kolguev Island. Potentially, they may find there other types of mollusks. The island's northern part remains unexplored. Additional studies are planned in the Pechora basin, from where most probably a significant part of freshwater malacofauna has got to the Kolguev Island.