Phylogenetic relationships of sculpin <Emphasis Type="Italic">Cottus volki</Emphasis> Taranetz, 1933 (Scorpaeniformes,Cottidae) according to the results of analysis of control region in mitochondrial DNA

Sequencing of the fragment of control region in mitochondrial DNA in sculpin Cottus volki and the comparison of obtained data with homologous nucleotide sequences in the other species from genus Cottus demonstrated that C. volki occupies the basal position in the “poecilopus” group, which includes also typical sculpin C. poecilopus Heckel, 1837 from water bodies of Europe, sculpin C. szanaga Dybowski, 1869 from the Amur River basin, and sculpin Cottus cf. poecilopus from the Lena River basin. Early separation of C. volki line from common trunk of “poecilopus” group explains the presence in C. volki of several primitive (plesiomorphic for this group) morphological characters: long interior ray of ventral fin, practically complete lateral body line, and well-developed dentition of palatine bones.     

Evolution of rough sculpin (<Emphasis Type="Italic">Cottus asperrimus</Emphasis>) genetic divergence and late Quaternary displacement on the Hat Creek fault,California, USA

The rough sculpin (Cottus asperrimus) is a threatened species whose geographic range in northwestern California, USA is disrupted by Hat Creek fault. We tested whether the fluvial barriers (rapids and waterfalls) produced by this fault have generated significant phylogeographic structure among rough sculpin populations by analyzing variation in microsatellites and mitochondrial DNA. Rough sculpin isolated on either side of Hat Creek fault exhibited significant genetic divergence (microsatellite F _ST = 0.36; mitochondrial uncorrected p distance = 1 %). Independently derived estimates for the date of divergence, based upon a molecular clock and upon the age of slip on the Hat Creek fault are concordant and indicate divergence was initiated about 0.5–1 million years ago. Based upon the findings of our genetic analysis and the Pleistocene geologic history of midsections of the Pit River, we present a model of evolution of rough sculpin genetic divergence and late Quaternary displacement on Hat Creek fault. Our findings reveal that rough sculpin exhibit significant population structure and that two management units should be recognized within the species for future conservation planning.     

Finding of Amur sculpin <Emphasis Type="Italic">Mesocottus haitej</Emphasis> and <Emphasis Type="Italic">Cottus szanaga</Emphasis> (Cottidae) in Tugur River basin (Khabarovsk krai,Russia)

The first official finding of the Amur sculpin Mesocottus haitej and Cottus szanaga is reported for the basin of Tugur River (Shantarsky zoogeographical region). Previously, these species were known for this region from the literature only.     

Redescription of <Emphasis Type="Italic">Cottus sibiricus</Emphasis> and an estimation of differences between this species and <Emphasis Type="Italic">Cottus dzungaricus</Emphasis> (Cottidae)

The type specimens of Cottus sibiricus and C. dzungaricus as well as individuals from the Olkha River (Yenisei River basin) are studied. The diagnostic features of C. sibiricus are established. Comparative morphological and molecular analysis of divergence between C. sibiricus and C. dzungaricus demonstrates that the differences lie within the limits of one polymorphous species. The rank of Dzungarian sculpin is lowered to the subspecies, C. sibiricus dzungaricus.     

Age-based demography and reproductive biology of three <Emphasis Type="Italic">Epinephelus</Emphasis> groupers, <Emphasis Type="Italic">E. polyphekadion,E. tauvina,</Emphasis> and <Emphasis Type="Italic">E. howlandi</Emphasis> (Serranidae), inhabiting coral reefs in Okinawa

The demography and reproductive biology of three Epinephelus groupers (Serranidae), namely E. polyphekadion, E. tauvina, and E. howlandi in the Yaeyama Islands, Okinawa, were examined based on age assessment using otoliths and gonadal histology. The maximum ages for these three species were 26 year, 23 year, and 17 year. The von Bertalanffy growth functions were also determined for each species. The size and age at 50% female maturity were estimated to be 358 mm in total length (TL) and 6.0 year for E. polyphekadion, 371 mm TL and 6.7 year for E. tauvina, and 327 mm TL and 4.1 year for E. howlandi, respectively. Significant differences between the sexes in size and age frequencies were found in all three species, with males being larger and older than females, or transitional individuals. These results strongly indicated that the population of these three grouper species showed monandric protogynous hermaphroditism. The sex ratios of E. polyphekadion and E. tauvina were biased in favor of females, but that of E. howlandi was equivalent between sexes. The relative sizes of ripe testes indicated that the intensity of sperm competition varied among species suggesting different mating system of each species. Reproductive seasonality was similar among species, with active vitellogenesis coinciding with the annual rise in water temperature. The active spawning period was determined to be between April and May for E polyphekadion, in May for E. howlandi, and from March to June for E. tauvina.     

Continued feeding on <Emphasis Type="Italic">Diporeia</Emphasis> by deepwater sculpin in Lake Huron

Monitoring changes in diets of fish is essential to understanding how food web dynamics respond to changes in native prey abundances. In the Great Lakes, Diporeia, a benthic macroinvertebrate and primary food of native benthivores, declined following the introduction of invasive Dreissena mussels and these changes were reflected in fish diets. We examined the diets of deepwater sculpin Myoxocephalus thompsonii collected in bottom trawls during 2010–2014 in the main basin of Lake Huron, and compared these results to an earlier diet study (2003–2005) to assess if their diets have continued to change after a prolonged period of Dreissena mussel invasion and declined Diporeia densities. Diporeia, Mysis, Bythotrephes, and Chironomidae were consumed regularly and other diet items included ostracods, copepods, sphaerid clams, and fish eggs. The prey-specific index of relative importance calculated for each prey group indicated that Mysis importance increased at shallow (≤55 m) and mid (64–73 m) depths, while Diporeia importance increased offshore (≥82 m). The average number of Diporeia consumed per fish increased by 10.0% and Mysis decreased by 7.5%, while the frequency of occurrence of Diporeia and Mysis remained comparable between time periods. The weight of adult deepwater sculpin (80 mm and 100 mm TL bins) increased between time periods; however, the change in weight was only significant for the 80 mm TL group (p?<?0.01). Given the historical importance of Diporeia in the Great Lakes, the examination of deepwater sculpin diets provides unique insight into the trophic dynamics of the benthic community in Lake Huron.     

<Emphasis Type="Italic">Viola woosanensis</Emphasis>, a recurrent spontaneous hybrid between <Emphasis Type="Italic">V. ulleungdoensis</Emphasis> and <Emphasis Type="Italic">V. chaerophylloides</Emphasis> (Violaceae) endemic to Ulleung Island,Korea

Ulleung Island is an oceanic volcanic island in Korea, which has never been connected to the adjacent continent. Previous studies highlighted Ulleung Island as an excellent system to study the pattern and process of early stages of flowering plant evolutions on oceanic island. The predominant mode of speciation in flowering plants on Ulleung Island appears to be anagenesis. However, the potentially important role of hybrid speciation among incompletely reproductively isolated lineages cannot be ruled out. Viola woosanensis (Violaceae) is of purportedly hybrid origin between V. ulleungdoensis (i.e., formerly recognized as V. selkirkii in Ulleung Island) and V. chaerophylloides, based on morphology. To examine the origin of V. woosanensis, we sampled a total of 80 accessions, including V. woosanensis and its putative parental species and sequenced nrDNA ITS, and four highly variable chloroplast noncoding regions (trnL-trnF, rpl16 intron, atpF-atpH, and psbA-trnH). Representative species of Viola from Korea were also included in the phylogenetic analyses (maximum parsimony, maximum likelihood, and Bayesian inference). Additive polymorphic sites in the nrDNA ITS regions were confirmed by cloning amplicons from representative species. The molecular data strongly supported the hybrid origin of V. woosanensis, and the maternal and paternal parent were determined to be V. ulleungdoensis and V. chaerophylloides, respectively. The presence of two parental ribotypes in V. woosanensis (with the exception in one population) was confirmed by cloning, suggesting V. woosanensis is primarily the F₁ generation. No trace of backcrossing and introgression with its parents was detected due to low fertility of hybrid species. We found a multiple and unidirectional hybrid origin of V. woosanensis. Additional studies are required to determine which factors contribute to asymmetric gene flow of Viola species in Ulleung Island.     

On the diversity of fishes in mountain lakes of the Amur basin

Results of the study of 11 lakes situated in the mountainous part of the Amur River basin are reported. Six fish species, namely, blunt-snouted lenok Brachymystax tumensis, Baikal-Lena grayling Thymallus baicalolenensis, Siberian stone loach Barbatula toni, Lagowski’s minnow Rhynchocypris lagowskii, Czekanowski’s minnow Rh. czekanowskii, and Amur sculpin Cottus szanaga, were found in five lakes. Four species were found in one lake (Lake Pereval’noe, basin of the Amgun’ River), and two species were found in each of the remaining lakes. Lenok and Amur sculpin were the most common species. The fauna of Lake Okonon (basin of the river Zeya) was the most specific and did not have analogs among the lake faunas; Czekanowski’s minnow and Baikal black grayling were found in this lake. The lenok ecotype that formed in the mountain lakes differed from the river lenok in some regards. The potential pathways of formation and protection of mountain lake ichthyocenoses of the Amur basin are discussed.     

Phylogenetic and taxonomic assessment of the endangered Cumberland bean, <Emphasis Type="Italic">Villosa trabalis</Emphasis> and purple bean, <Emphasis Type="Italic">Villosa perpurpurea</Emphasis> (Bivalvia: Unionidae)

Inadequate understanding of the phylogeography, taxonomy, and historical distribution of two critically imperiled freshwater mussels, Cumberland bean, Villosa trabalis, and purple bean, Villosa perpurpurea, has hindered management and recovery actions related to population restoration within their extant ranges. For more than 100 years, the purple-to-pink nacre of V. perpurpurea and white nacre of V. trabalis have been the only defining phenotypic characteristics used to distinguish each species. Genetic samples were analyzed from 140 individuals collected from 10 streams located in Virginia, Tennessee, and Kentucky, representing all known extant populations of each species. A 784-bp section of the mitochondrial DNA ND1 region was sequenced to assess the phylogeography and taxonomic validity of these taxa. Results of our phylogenetic analyses showed 100 % Bayesian posterior support for two distinct clades, one occurring in the Cumberland River basin and the other in the Tennessee River basin, separated by a mean genetic distance of 4 %. Mean genetic distances between haplotypes within each clade was <1 %. Among individuals from the Cumberland River basin, the nacre of shells was white to bluish-white, but in the Tennessee River basin, nacre graded from white to pink to dark purple; thus, nacre color is a variable and inconsistent character in nominal V. trabalis and V. perpurpurea occurring in the Tennessee River basin. Our data suggest that these morphologically similar species do not co-occur, as was previously believed. Instead, we conclude that the two species most likely share a common ancestor, but became isolated within each basin and experienced allopatric speciation. Updates to nomenclature, taxonomic placement, and recovery plans for the investigated species are needed.     

Same habitat,different species: otolith microchemistry relationships between migratory and resident species support interspecific natal source classification

We tested the hypothesis that otolith trace elemental signatures (microchemistries) of mottled sculpin Cottus bairdi, slimy sculpin C. cognatus, and juvenile coho salmon Oncorhynchus kisutch were predictive of those of juvenile steelhead O. mykiss across many sites within the Lake Michigan basin. Laser ablation inductively coupled plasma mass spectrometry was used to generate otolith microchemistry signatures for each individual fish. For each species pair, statistical correlations of mean otolith concentrations of Mg, Mn, Cu, Zn, Sr, Ba, and Pb for each site were estimated. Linear equations describing these relationships were used to transform juvenile steelhead otolith microchemistry data to those of each of the other species. Transformed otolith microchemistry data were subjected to random forest classifications developed for mottled sculpin, slimy sculpin, and juvenile coho salmon to assess interspecific natal source assignment accuracies. Steelhead otolith concentrations of Sr were significantly correlated with those of each of the other species, whereas otolith concentrations of Ba and Mn were significantly correlated among some species pairs, but not others. Natal source assignment accuracies of juvenile steelhead to site and watershed generally decreased when otolith microchemistry data were transformed to those of mottled sculpin, slimy sculpin, and coho salmon. Miss-assigned fish often classified into nearby watersheds within larger hydrologic units, leading to higher assignment accuracies at coarser geographical resolutions (75–97% correct assignment to hydrologic unit for each species). These findings suggest that applications of otolith microchemistry data may extend beyond the species from which they are collected.     

Variation in the <Emphasis Type="Italic">COI</Emphasis> gene of the freshwater pearl mussel <Emphasis Type="Italic">Margaritifera margaritifera</Emphasis> from River Vuokkijoki

The freshwater pearl mussel Margaritifera margaritifera L. is one of the most endangered freshwater mussels in the world. Effective conservation of threatened species requires not only ecological, but also genetic information from the target species and populations. Since low genetic diversity can reduce the ability of a species to adapt to environmental changes, maintaining genetic diversity has been identified as one of the key elements in successful conservation programs. We examined genetic variation of the freshwater pearl mussel from the River Vuokkijoki, Karelia, Russia. We sequenced a fragment of the cytochrome c oxidase subunit I gene (COI) from 22 individuals and compared the data to 32 previously published COI sequences available in GenBank. We identified 10 different COI haplotypes in the sequenced samples, three of which had not been previously reported. Our results show that the River Vuokkijoki has high genetic diversity and suggest that the colonization of this northern freshwater pearl mussel population might have occurred from multiple and even distant refugia. Therefore, the freshwater pearl mussel population of the River Vuokkijoki is valuable for the conservation of the whole species.     

Seasonal feeding ecology of co-existing native and invasive benthic fish along a nearshore to offshore gradient in Lake Michigan

Relative abundance, diet composition and feeding strategy were determined for three benthic fish, the native deepwater sculpin Myoxocephalus thompsonii (Girard, 1851) and slimy sculpin Cottus cognatus (Richardson, 1836), and the invasive round goby Neogobius melanostomus (Pallas, 1814), along a nearshore to offshore gradient in southeastern Lake Michigan during March–December 2010, 2015, and 2016. Round goby were most abundant in the nearshore (<25 m), slimy sculpin were most abundant in the transitional zone (35–65 m), and deepwater sculpin were most abundant in the offshore zone (>75 m). Despite a large degree of spatial separation, some species did overlap, with slimy and deepwater sculpin occurring in sympatry throughout the year in the offshore and transitional zones, and round goby overlapping with both sculpin species seasonally in the transitional zone. Deepwater sculpin exhibited specialization on Mysis diluviana in all depth regions. Slimy sculpin in the offshore reduced diet overlap with deepwater sculpin by specializing on fish eggs during spring and fall, whereas in the transitional depth zone, there was considerable overlap between sculpin species due to the high importance of Mysis in diets. The invasive round goby had a mixed diet, with some diet overlap with native sculpin, especially slimy sculpin, in the transitional zone. In the nearshore zone, round goby displayed a generalized diet with many prey contributing to the diet, but the average contribution of any prey was generally low. Spatial separation and variable feeding strategies help reduce, but not eliminate shared resource use amongst these benthic fish in Lake Michigan.     

Growth and reproduction of the north-eastern Atlantic keystone species <Emphasis Type="Italic">Patella aspera</Emphasis> (Mollusca: Patellogastropoda)

The growth and reproductive biology of the limpet Patella aspera were studied in the north-eastern Atlantic, Madeira archipelago, to enhance the knowledge concerning biological parameters and population dynamics of this species. This study comprised the estimation of growth rates, sexual maturity, reproduction, recruitment patterns, mortality coefficients and the exploitation rate, and yield-per-recruit (Y/R) based on monthly shell-length frequency data. A total of 16,941 specimens were sampled from January to December 2015. The relative growth pattern exhibited a negative allometric nature of growth for both sexes. The estimated von Bertalanffy growth parameters showed an asymptotic length of 84.15 mm for females and 80.51 mm for males with a growth coefficient of 0.36 and 0.32 year^?1 respectively. P. aspera in this geographical area is a moderately long-lived limpet with a predominance of specimens younger than 3 years old. This species is a winter breeder with a reproductive cycle encompassing three main periods namely development, spawning and resting with a synchronous gametogenesis for both sexes. Gonadal development lasts from October to December, spawning likely occurs from January until April and resting occurs from May to September. The mean size at sexual maturity was determined as 41.78 mm for females and 38.29 mm for males and the length at first capture as 42.62 mm. The recruitment pattern was continuous throughout the year with a major peak identified in March. The natural, fishing and total mortalities were similar between sexes, with fishing mortality exerting greatest pressure on this resource. However, yield-per-recruit analysis showed that the stock of P. aspera, in the study area, is exploited at levels below the fishing mortality that returns maximum sustainable yield. This study revealed that currently the stock of P. aspera is under-exploited, nonetheless due to it’s slow growth and long life, continuous monitoring and the enforcement of the existing harvest regulations must be accomplished if future over-exploitation is to be avoided. Further genetic studies are necessary to establish connectivity of the populations and improve present conservation strategies.     

Ultrastructure of saccular epithelium sensory cells of four sculpin fish species (Cottoidei) of Lake Baikal in relation to their way of life

Various structural elements of the apical region of hair cells and their location in the saccular macula of four sculpin fish species (Cottoidei) of Lake Baikal—two oilfish species (big golomyanka Comephorus baicalensis and small golomyanka C. dybowski), Severobaikalsk yellowfin Cottocomephorus alexandrae, and stone sculpin Paracottus knerii—were studied by scanning electron microscopy. In stone sculpin Paracottus knerii, which inhabits the coastal areas and leads a benthic lifestyle, the diversity of hair cells (in terms of the height of kinocilium and stereocilia) is big than that in the secondary pelagic species big and small golomyankas and in Severobaikalsk yellowfin, which inhabits the near-slope areas. Stereocilia of hair cells of stone sculpin and Severobaikalsk yellowfin are shorter than in the other species studied. The presence of such cells in the macula can ensure the sensitivity to more high-frequency acoustic signals and facilitate their perception by fish against the background of low-frequency noises characteristic of the coastal zone of the lake.     

Detection and Quantification of <Emphasis Type="Italic">Vibrio cholerae,Vibrio parahaemolyticus</Emphasis>, <Emphasis Type="Italic">and Vibrio vulnificus</Emphasis> in Coastal Waters of Guinea-Bissau (West Africa)

V. cholerae, V. parahaemolyticus, and V. vulnificus are recognized human pathogens. Although several studies are available worldwide, both on environmental and clinical contexts, little is known about the ecology of these vibrios in African coastal waters. In this study, their co-occurrence and relationships to key environmental constraints in the coastal waters of Guinea-Bissau were examined using the most probable number-polymerase chain reaction (MPN-PCR) approach. All Vibrio species were universally detected showing higher concentrations by the end of the wet season. The abundance of V. cholerae (ISR 16S-23S rRNA) ranged 0–1.2 × 10⁴ MPN/L, whereas V. parahaemolyticus (toxR) varied from 47.9 to 1.2 × 10⁵ MPN/L. Although the presence of genotypes associated with virulence was found in environmental V. cholerae isolates, ctxA+ V. cholerae was detected, by MPN-PCR, only on two occasions. Enteropathogenic (tdh+ and trh+) V. parahaemolyticus were detected at concentrations up to 1.2 × 10³ MPN/L. V. vulnificus (vvhA) was detected simultaneously in all surveyed sites only at the end of the wet season, with maximum concentrations of 1.2 × 10⁵ MPN/L. Our results suggest that sea surface water temperature and salinity were the major environmental controls to all Vibrio species. This study represents the first detection and quantification of co-occurring Vibrio species in West African coastal waters, highlighting the potential health risk associated with the persistence of human pathogenic Vibrio species.     

New data about distribution of lower Amur grayling <Emphasis Type="Italic">Thymallus tugarinae</Emphasis> and Baikal-Lena grayling <Emphasis Type="Italic">Thymallus</Emphasis> sp. (Thymallidae) in the basins of the upper Amur River and Zeya River

New findings of lower Amur grayling (Lower Amur grayling) Thymallus tugarinae and Baikal-Lena grayling Th. sp. (Th. baicalolenensis) in the basins of the upper Amur River and Zeya River are reported for 2010?2014. Lower Amur grayling has been registered in the tributaries of Argun River and in the middle stream of Ingoda River. Baikal-Lena grayling has been found for the first time in the headstream of Ingoda River. New data about the distribution of this species in the basin of upper stream of Zeya River are reported; particularly, Baikal-Lena grayling has been found in Okonon Lake; this is the first finding of a representative of Thymallidae family in the alpine lakes of the watershed area of Amur River. In the basins of upper Amur River and Zeya River, the summer ranges of upper Amur grayling Th. grubii grubii and lower Amur grayling overlap to some extent; on the other hand, the ranges of Baikal-Lena grayling and lower Amur grayling are disjoint. During the summer period, upper Amur grayling and Baikal-Lena grayling together inhabit the basin of upper stream of Zeya River, but only Baikal-Lena grayling has been found in the headstream of Zeya River. In the basin of upper Amur River (the headstream of Ingoda River), the joint range of these species is still unknown; the sympatric zone is located in Dzhermoltai River (the basin of Onon River).     

Dynamics of species composition of fish and some results of ichthyomonitoring in the middle course of the Oka (Ryazan oblast)

The dynamics of species composition of fish from the middle course of the Oka is considered. A total of 53 species of Cyclostomata and fish was previously recorded; however, only 43 species have been found at the present time. Due to different causes, ten species have disappeared, and ten new species have emerged. The species composition and structure of aboriginal fish population are characterized by relative stability; however, the total abundance of fish during the current decade, as compared to the 1970s, has considerably decreased. The sterlet Acipenser ruthenus, lake minnow Phoxinus precnurus, Volga zander Sander volgensis, and freshwater sculpin Cottus gobio belong to rare fish.     

Genetic diversity and population structure of the roughskin sculpin (<Emphasis Type="Italic">Trachidermus fasciatus</Emphasis> Heckel) inferred from microsatellite analyses: implications for its conservation and management

Identification of population units is crucial for management and monitoring programs, especially for endangered wild species. The roughskin sculpin (Trachidermus fasciatus Heckel) is a small catadromous fish and has been listed as a second class state protected aquatic animal since 1988 in China. To achieve sustainable conservation of this species, it is necessary to clarify the existing genetic structure both between and within populations. Here, population genetic structure among eight populations of T. fasciatus were analyzed by using 16 highly polymorphic microsatellites. High levels of genetic variation were observed in all populations. All pairwise F _ST estimates were significant after false discovery rate correction (overall average F _ST = 0.054). Furthermore, both STRUCTURE and discriminant analysis of principal components (DAPC) analysis showed that the eight populations were grouped into six clusters. BAYESASS analysis showed generally low recent and asymmetric migration among populations. All these results suggested significant genetic structure across populations. However, there was no isolation by distance relationship among populations, likely resulting from barriers to gene flow created by habitat fragmentation. Our results highlight the need for in situ conservation efforts for T. fasciatus across its entire distribution range, through maximizing habitat size and quality to preserve overall genetic diversity and evolutionary potential.     

Variation of stone sculpin <Emphasis Type="Italic">Paracottus knerii</Emphasis> (Cottidae,Scorpaeniformes) of Baikal and waters of Baikal region

Sixteen samples of the stone sculpin Paracottus knerii from Baikal Lake, Angara River, and seven water bodies of the Baikal and Angara basins are studied. Variation of the morphometric and meristic characters is considered. It is found that the variation of a number of characters is biotopically conditioned and directed at fish adaptation to deepwater and dwelling in the conditions of rapid current. There are also the characters whose variation does not show any regularity, and it is a consequence of the discontinuity of range of the species. It is shown that the individual pairs of populations have differences in a number of characters, and these differences conform to the subspecies (CD > 1.28) and species levels (presence of hiatus). However all such pairs are connected by “ring overlaps,” thus, it is not possible to consider them as independent taxa.