Valeri Vasil’ev

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To date, about 85 forms and species of fish, amphibia, and reptiles have been described that are represented by only females that reproduce via parthenogenesis, gynogenesis, or hybridogenesis. In the case of gynogenesis, characteristic of fish and amphibia, participation of males is required, whose spermatozoa only stimulate the development of genetically(More)
Recently, applications of cooperative game theory to economic allocation problems have gained popularity. We investigate a class of cooperative games that generalizes some economic applications with a similar structure. These are the so-called line-graph games being cooperative TU-games in which the players are linearly ordered. Examples of situations that(More)
The karyology of species of sturgeon from the Russian Far East demonstrates that the karyotype of the Sakhalin sturgeon (Acipenser mikadoi) includes 262 ± 4 chromosomes with 80 biarmed chromosomes and the number of chromosome arms (NF) 342 ± 4, the karyotype of the Amur sturgeon (A. schrenckii) includes 266 ± 4 chromosomes with 92 biarmed chromosomes and NF(More)
Data are first provided on karyotypes of four species of Cobitidae from the Amur Basin: Misgurnus nikolskyi (2n = 50 = 10m + 4 sm + 36sta, NF = 64), Cobitis lutheri, (2n = 50 = 12m + 8sm + 30sta, NF = 70), C. choii (2n = 50 = 8m + 10sm + 8st + 24a, NF = 68), and C. melanoleuca (2n = 50 = 6m + 16sm + 28sta, NF = 72), and number of chromosomes in M. mohoity(More)
107 In the river basins of Central and Eastern Europe, at least seven diploid bisexual spined loach species form the genus Cobitis are found. These are C. taenia, C. rossomeridionalis (some authors consider this species a junior synonym of C. tanaitica ), C. elongatoides (a spined loach species from the Danube basin that is sometimes referred to as C.(More)
Several dozens of unisexual fish species and forms, whose reproduction is brought about due to specific cytogenetic mechanisms, have been found by now [1, 2]. These species are represented by females only and are characterized by clonal or semiclonal inheritance based on natural gynogenesis, when females produce nonreduced eggs with genomes identical to the(More)
We describe spined loaches from the Kyzylagach Bay (Azerbaijan) and from brackish waters of the northeastern Caspian Sea found in museum collections as a separate new species, the Khvalyn loach Cobitis amphilekta. The new species differs from other species of the Caspian basin in the following combination of characteristics: one very narrow, weakly(More)
228 Polyploidy has played an important role in the Acipenseriformes evolution. No modern study on the phylogeny of this group does without ploidy data. In addition, current concepts on the phylogenetic relationships of Acipenseriformes, which have been developed on the basis of cytogenetic and molecular genetic analyses, conflict with the traditional(More)
A situation in which a finite set of players can obtain certain payoffs by cooperation can be described by a cooperative game with transferable utility, or simply a TU-game. A solution for TU-games assigns a set of payoff vectors to every TU-game. Some solutions that are based on distributing dividends are the Shapley value (being the single-valued solution(More)
Results are described of experimental crossing for obtaining of triple hybrids of the Russian sturgeon Acipenser gueldenstaedtii, the great sturgeon A. huso, and the starred sturgeon A. stellatus and of comparative analysis of some quantitative morphological characters in these hybrids, in the progeny of parental species and of reciprocal hybrids of starred(More)