V. P. Vasil’ev

Cobitis faridpaki sp. nova—a New spined loach species (Cobitidae) from the southern Caspian Sea basin (Iran)

Spined loaches from the Siahrud River of the southern coast of the Caspian Sea in the province of Mazandaran, north of Iran, are described as a new species Cobitis faridpaki. This species belongs to Cobitis species group with a single lamina Canestrini at the base of the second pectoral-fin ray in males and subdorsal scales with reduced eccentric focal zone. These characters differentiate C. faridpaki from both southern Iranian species C. linea and C. melanoleuca distributed in the northern Caspian Sea basin. The stout body, small and numerous (25–30) lateral spots and the presence of 14–16 branched caudal-fin rays separate C. faridpaki from Caucasian species C. satunini.

How many times has polyploidization occurred during acipenserid evolution? New data on the karyotypes of sturgeons (Acipenseridae, Actinopterygii) from the Russian Far East

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 358 ± 4, and the karyotype of the kaluga (A. dauricus) consists of 268 ± 4 chromosomes with 100 biarmed chromosomes and NF 368 ± 4. These results prove that all western Pacific sturgeon species are from a tetraploid origin, based on a recent ploidy scale. This suggests that at least three polyploidization events have occurred during the evolution of Acipenseridae. However, if polyploid species originated by hybridization between diploid species, there may have been more polyploidization events in this group of fishes.

The Revision of the Validity of Genus Huso (Acipenseridae) Based on Recent Morphological and Genetic Data with Particular Reference to the Kaluga H. dauricus

The comparative morphological study in different Acipenseriform species demonstrates that there are only two morphological features combining the kaluga and the great sturgeon and separating them from other sturgeons, namely the shape of a mouth and the manner attaching of gill membranes to isthmus in adult specimens; whereas many morphological characters are different in these species. The relations of morphological similarity/distinction among different sturgeon species and polyphyletic origin of genus Huso revealed by both molecular and cytogenetic studies presume the restoration of initial taxonomic states for the great sturgeon and kaluga as members of the same genus Acipenser, namely A. huso and A. dauricus.

Comparative karyology of species of the genera Misgurnus and Cobitis (Cobitidae) from the Amur River Basin in connection with their taxonomic relations and the evolution of karyotypes

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 (2n = 50) and karyotypes of C. melanoleuca from the basin of the Don, Malyi and Bol’shoi Uzen rivers, and Selenga. These data are discussed in connection with problems of taxonomy of the studied genera, as well as the evolutionary relations of their karyotypes. On the basis of karyological differences between the populations of C. melanoleuca from different parts of the range, a new subspecies C. melanoleuca gladkovi subsp. nov. that inhabits waters of Europe is described.

Reconstruction of phylogenetic relations of Ponto-Caspian gobies (Gobiidae, Perciformes) based on mitochondrial genome variation and some problems of their taxonomy

Phylogenetic relations of Ponto-Caspian gobies in the context of different taxonomic hypotheses have been studied based on the analysis of variations in cytochrome b gene. Evidence for the paraphyly of the genus Neogobius sensu lato, represented by two independent phyletic lineages that should be treated as separate genera Neogobius s. stricto (includes a species group of N. melanostomus-N. fluviatilis-N. caspius) and Ponticola, has been provided. It has been demonstrated that the Racer goby N. gymnotrachelus refers to the latter genus. It is proved that the Grass goby Gobius ophiocephalus belongs to the genus Gobius s. stricto.

Cobitis pontica sp. nova—a new spined loach species (Cobitidae) from the Bulgarian waters

Spined loaches from the Veleka River (Black Sea coast of Bulgaria), earlier confirmed to represent a separate evolution lineage within a 50-chromosome morph occurring in the Black Sea basin, are described as a new species. This species has the karyotype (2n = 50, NF = 90) similar to one from earlier described C. taurica occurring in the Crimean Peninsula, but differs from it by larger and less numerous spots in the fourth Gambetta’s zone of pigmentation and more anterior position of suborbital spine.

Cobitis amphilekta sp. nova, a new species of spined loaches (Cobitidae, Cypriniformes) from the Caspian Sea basin

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 discernible spot in the upper part of the base of the caudal fin; Canestrini’s organ in males with a wide and short plate, usually not reaching the end of the third segment of the attached ray; third Gambetta’s zone of pigmentation usually not reaching the base of the anal fin, often not reaching the end of the pectoral fin; scales of oval shape, with a relatively large central part, weakly shifted towards the anterior margin; pronounced ridges on the margins of the caudal penduncle; and short barbels.

The validation of specific status of the sakhalin sturgeon Acipenser mikadoi (Acipenseridae) in the light of recent genetic and morphological data

The taxonomic relations between the Sakhalin and North American green sturgeons were re-evaluated based on afresh conducted comparative morphological analysis of both sturgeons, as well as a renovation of literature cytogenetic, molecular and morphological data. The comparative analysis of different data sets demonstrates the validity of the Sakhalin sturgeon A. mikadoi which differs from the North American green sturgeon A. medirostris in the karyotype structure, the nuclear DNA content value, and several morphological characters. The key for their identification is presented.

The gynogenetic form of fish from the genus Cobitis (Cobitidae) in a region of its geographic range is monoclonal: DNA fingerprinting data.

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 maternal one. After insemination, no true fertilization occurs, because sperms only stimulate egg development. In genetic terms, natural gynogenesis is indistinguishable from parthenogenesis. Reproduction systems differing from the bisexual one are found in fish of the genera Poecilia , Poeciliopsis , Menidia , Fundulus , Phoxinus , Carassius , Rutilus (Tropidophoxinellus), and Cobitis . The species and forms reproduced in the manner described above are combined with closely related bisexual species into complexes that are usually referred to as clonal-bisexual or diploid-polyploid complexes. The diploid species and hybrid forms are sometimes morphologically indistinguishable. We previously found a clonal-bisexual complex of Cobitis in the Moscow River near Zvenigorod [3]. This complex includes two diploid species ( C. taenia and C. melanoleuca ), a triploid form, and two tetraploid forms. The triploid genome (3 n = 74) contains the diploid number of chromosomes of an unknown species (2 n = 50) and the haploid number of C. taenia chromosomes ( n = 24). In one of the tetraploid forms, the genome of triploid form and the haploid genome of C. taenia were found. The triploid form is represented only by females that are reproduced by gynogenesis [4]. To date, the clonalbisexual complexes of fish of the genus Cobitis are found in many basins of Eastern and Western Europe [4 − 6]. Analysis of the clonal structure of the unisexual forms is an important line in studying the clonal–bisexual fish complexes. This report presents data on the clonal structure of the unisexual triploid form of Cobitis from the Moscow River that was determined for the first time using multilocus DNA fingerprinting. The monoclonal structure of triploid Cobitis from a locality of the Zvenigorod area of the Moscow River was confirmed using various restrictase/probe combinations. Adult individuals of the genus Cobitis that were ready for reproduction were caught in June 2002 in spawning grounds in the Moscow River near the Zvenigorod Biological Station of the Moscow State University. Fish ploidy was determined by the number of chromosomes and erythrocyte square. Thirty six gynogenetic Cobitis were selected for our analysis. The blood of adult individuals was sampled using EDTA as an anticoagulant. DNA was isolated from the blood by the standard phenol–chloroform method using proteinase K. DNA samples were treated with restriction endonucleases and analyzed by blot-hybridization with a [ 32 P ]-labeled probe [7]. Since the DNA-fingerprinting pattern depends only on the restrictase and the probe [8], we used the following restrictase/probe combinations: Bsu RI/(GACA) 4 , Mva I, Bsu RI/(TCC) 5 , Mva I/(CAC) 5 , Hinf I, Mva I/Jeffrey’s core 33.15, Hinf I, Mva I/(TCT) 6 , Bsu RI, Hinf I, Mva I/(GATA) 4 , Bsu RI, Hinf I, and Mva I/(CT) 9 . Nineteen fingerprinting patterns of triploid gynogenetic individuals, which were obtained using microsatellite probes (TCC) 5 , (CT) 9 , (TCT) 6 , and (GATA) 4 and various restrictases, are shown in the figure. Regarding the distribution of the fingerprinting pattern fragments, no differences were found between triploids of the populations studied; i.e., all of them represented a single clone. With all the above restrictase/probe combinations, identical patterns were obtained for 36 analyzed individuals. DNA fingerprinting was used in this study for the first time to determine the clonal origin of gynogenetic fish of the genus Cobitis . This is the most efficient method for detecting even minor interindividual genomic distinctions [8]. Our results testify to the genetic homogeneity of the group of Cobitis studied. These data differ from the evidence previously obtained [9] on the gynogenetic fish Poecilia formosa. Using GENERAL BIOLOGY

Field effect in a graphene oxide transistor for proton and electron–hole conductivities

Proton (wet atmosphere) and electron (reduced graphene oxide) conductivities can be observed in graphene oxide films. The field effect in a graphene oxide transistor for different conductivity types has been discovered and investigated.