title: Reproduction of Pisidium casertanum (Poli, 1791) in Arctic lake.
abstract: Freshwater invertebrates are able to develop specific ecological adaptations that enable them to successfully inhabit an extreme environment. We investigated the brooding bivalve of Pisidium casertanum in Talatinskoe Lake, Vaigach Island, Arctic Russia. Here, quantitative surveys were conducted, with the collection and dissections of 765 molluscs, on the basis of which analyses on the brood sacs length (marsupia) and the number and size of embryos, were performed. In this study, the number of brooded embryos was positively correlated with the parent's shell length. The number of extramarsupial embryos was much lower than the number of intramarsupial embryos. Our research also showed that the brood sac length and embryos within one individual can vary significantly. Thus, we detected that P. casertanum has a specific brooding mechanism, accompanied by asynchronous development and embryos release by the parent. We suggest that such a mode could result in the coin-flipping effect that, presumably, increases the population breeding success in the harsh environment of the Arctic lake.
authors.affiliation: Institute of Ecological Problems of the North, The Ural Branch of the Russian Academy of Sciences , Severnaya Dvina Emb. 23, 163000 Arkhangelsk, Russian Federation.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Bespalaya
authors.affiliation: Institute of Ecological Problems of the North, The Ural Branch of the Russian Academy of Sciences , Severnaya Dvina Emb. 23, 163000 Arkhangelsk, Russian Federation.
authors.forename: Ivan
authors.initials: I
authors.lastname: Bolotov
authors.affiliation: Institute of Ecological Problems of the North, The Ural Branch of the Russian Academy of Sciences , Severnaya Dvina Emb. 23, 163000 Arkhangelsk, Russian Federation ; Northern (Arctic) Federal University , Severnaya Dvina Emb. 17, 163002 Arkhangelsk, Russian Federation.
authors.forename: Olga
authors.initials: O
authors.lastname: Aksenova
authors.affiliation: Institute of Ecological Problems of the North, The Ural Branch of the Russian Academy of Sciences , Severnaya Dvina Emb. 23, 163000 Arkhangelsk, Russian Federation ; Northern (Arctic) Federal University , Severnaya Dvina Emb. 17, 163002 Arkhangelsk, Russian Federation.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kondakov
authors.affiliation: Institute of Ecological Problems of the North, The Ural Branch of the Russian Academy of Sciences , Severnaya Dvina Emb. 23, 163000 Arkhangelsk, Russian Federation.
authors.forename: Inga
authors.initials: I
authors.lastname: Paltser
authors.affiliation: Institute of Ecological Problems of the North, The Ural Branch of the Russian Academy of Sciences , Severnaya Dvina Emb. 23, 163000 Arkhangelsk, Russian Federation ; Northern (Arctic) Federal University , Severnaya Dvina Emb. 17, 163002 Arkhangelsk, Russian Federation.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Gofarov
keywords: Arctic; Pisidium species; adaptive coin-flipping; adaptive strategy; asynchronous brooding; embryonic growth