Population structure of haarder <Emphasis Type="Italic">Liza haematocheila</Emphasis> (Mugiliformes,Mugilidae) acclimatized in the Sea of Azov Basin

As a result of the successful acclimatization in the Azov basin, haarder Liza haematocheila has become a commercial species and is currently among the main commercial items. Its reproduction in the new range takes place in environmental conditions strongly differing in the salinity level (3–24‰), which determined its population differentiation. The extent and structure of the phenetic diversity of L. haematocheila from the Sea of Azov basin was assessed and elucidated, using a phenetic approach in studies of natural populations and on the basis of studying morphological characters. Molochnyi Liman, Sivash, and marine subpopulations of L. haematocheila were distinguished.     

Genetic variability of anchovy in the Azov-Black Sea basin

The intraspecific structure of the European anchovy (Engraulis encrasicolus) was studied on the basis of mitochondrial cytochrome b gene (cytb) fragment variability in 84 individuals from seven localities of the Black Sea and the Sea of Azov. The data on haplotype and nucleotide diversity and the values of neutrality tests suggested expansive growth of anchovy populations in the Azov-Black Sea basin. All samples from anchovy populations demonstrated a high level of haplotype diversity (Hd = 0.962). Two dominant haplotypes were identified, the frequencies of which were not directional, and they were present in all localities. Sequence analysis of the mitochondrial cytb gene fragment showed no differentiation between the Sea of Azov and the Black Sea subspecies.     

The ultrastructure of the interstitial cells of the mesonephros in the teleost fishes of the Black Sea

The ultrastructure of cells that form mesonephros tissues in eight species of bony fish of the Black Sea, Gaidropsarus mediterraneus (L.), Lisa aurata (Risso), Trachurus mediterraneus (Staindachner), Diplodus annularis (L.), Spicara flexuosa (Rafinesque), Gobius niger jozo L., Mullus barbatus ponticus (Essipov) and Scorpaena porcus (L.), was studied. It was shown that the ultrastructure of agranulocytes and rodlet cells in the studied species is similar to that of cells in freshwater bony fish. The differences were observed in the number of ionocyte mitochondria, in the vesicle ultrastructure in the cells with radial vesicle array, and in the ultrastructure of the specific secondary granules of neutrophils and eosinophils.     

Taxonomic composition and interannual variations in numerical density of meroplankton in the Sea of Azov

This paper presents data on the taxonomic composition and dynamics of numerical density of meroplankton in the Sea of Azov. Studies performed in June 2003–2005 revealed benthic invertebrate larvae of 26 taxa: Polychaeta, 7; Cirripedia, 1; Decapoda, 5; Gastropoda, 5; and Bivalvia, 8. Meroplankton was dominated by larvae of species that are able to endure considerable concentrations of pollution by labile sulfides in bottom sediments and eutrophication: Mytilaster lineatus, Cerastoderma sp., Abra ovata (Philippi), Hydrobia acuta (Gastropoda), and Amphibalanus improvisus (Cirripedia). The spatial and temporal variations in the structure of dominant species and numerical abundance of meroplankton in the Sea of Azov are likely to be associated with water temperature fluctuations, pelagic predators, and eutrophication. Under anthropogenic stress and predation pressure, most larvae of benthic invertebrates are apparently unable to complete metamorphosis and contribute to recruitment to parental populations. Thus, the numerical density of meroplankton in the Sea of Azov can significantly vary, even over one month.     

Descriptions of eight new species of <Emphasis Type="Italic">Ligophorus</Emphasis> Euzet &; Suriano, 1977 (Monogenea: Ancyrocephalidae) from Red Sea mullets

Eight new species of Ligophorus Euzet &; Suriano, 1977 (Monogenea: Ancyrocephalidae) are described from two species of mullets from the Red Sea. Ligophorus bykhowskyi n. sp. and L. zhangi n. sp. from Crenimugil crenilabris (Forsskål) differ from other species of the genus in the structure of the male copulatory organ, which has a simple accessory piece and a wide copulatory tube that arises from a large, single-chambered, expanded base. Ligophorus simpliciformis n. sp., L. bipartitus n. sp., L. campanulatus n. sp., L. mamaevi n. sp., L. lebedevi n. sp. and L. surianoae n. sp. from Liza carinata (Valenciennes) are differentiated on the basis of the morphometrics of the hard parts of the haptor and male copulatory organ. The eight species represent the first records of species directly attributed to Ligophorus from the Red Sea. Measurements of the haptoral hard-parts and the male copulatory organ of the new species are analysed with the aid of Principal Component Analysis. Three morphological types of male copulatory organ, five types of anchor, and two types of ventral and three types of dorsal bars were distinguished among these species. L. bykhowskyi and L. zhangi from C. crenilabris have the same type of male copulatory organ and anchors. Those species from Liza carinata have only one common morphological character, a thick copulatory tube, but have two types of accessory piece, four types of anchors and three types of bars. All species of Ligophorus found on mullets in the Red Sea have an accessory piece without a distal bifurcation and thus differ from most species of this genus from other regions of the world’s oceans.     

Findings of new and rare fish species in the coastal zone of the Crimea (the Black Sea)

Characteristics of seven Atlantic-Mediterranean fish species are provided. Of them, four (gobies—yellow-headed Gobius xanthocephalus and red-mouthed G. cruentatus, incognito blenny Parablennius incognitus, and greater pipefish Syngnathus acus) were either first found in the Black Sea coastal zone of the Crimea, or their findings were doubted, and three species (thin-lipped grey mullet Liza ramada, European barracuda Sphyraena sphyraena, and Black Sea salmon Salmo trutta labrax) are very rare. Over the last decade, the authors recorded 15 fish species; of them, seven Atlantic-Mediterranean species have dispersed along the Crimean coasts by now, one endemic of the far eastern seas (chameleon goby Tridentiger trigonocephalus) has naturalized in Sevastopol Bay, four invading species, freshwater by origin, permanently occur in the estuary zones of the peninsula; the remaining three species are known from single findings and apparently belong to the category of accidental fish. An increase in the species composition of ichthyofauna off the Black Sea coasts of the Crimea results from the on-going process of mediterranization—the invasion in the estuary of freshwater tolerant species at the expense of accidental species that penetrated here either independently or with ballast waters.     

Phylogenetic relationships of nine mullet species (Mugilidae) in the Mediterranean Sea

Phylogenetic relationships among four genera and nine species (Mugil cephalus, Mugil soiuy, Liza ramada, Liza aurata, Liza abu, Liza saliens, Liza carinata, Chelon labrosus, Oedalechilus labeo) of the Mediterranean mullets (Mugilidae) were investigated by means of allozyme electrophoresis using a seven-enzyme system (CK*, GAPDH*, G3PDH*, IDHP*, ME*, MDH*, PGM*) comprising eleven putative loci. The highest genetic divergence was 1.299, detected between M. cephalus and L. aurata and the lowest (0.280) was found between L. carinata and L. saliens. The amount of genetic divergence between the genera Chelon and Oedalechilus did not appear to be high (0.285). In a UPGMA tree, all nine species were grouped in two main branchings. In the first branch, C. labrosus and O. labeo clustered as closest taxa and were sister group to L. ramada. The other four Liza species produced two sub-branching in this group; L. carinata branched together with L. saliens, and L. aurata branched together with L. abu. In the second branch the two species of the genus Mugil, M. cephalus and M. soiuy, clustered together and were clearly isolated from the other three genera.     

Ecosystem of Caspian Sea threatened by pet-traded non-indigenous crayfish

Freshwater ecosystems are particularly vulnerable to biological invasions; the aquatic animal pet trade has been recognized as a significant pathway of introductions. Crayfish are considered a model group of traded organisms with a series of highly successful species already established in the wild, having the potential to negatively influence both indigenous crayfish species (ICS) as well as alter occupied ecosystems. Eastern Europe includes the entire native ranges of indigenous Astacus leptodactylus sensu lato and A. pachypus. This region has been largely overlooked and considered relatively safe from the adverse impacts of non-indigenous crayfish species (NICS). In this study, we evaluated the crayfish pet trade in the Lower Volga Region with special emphasis on Astrakhan, the biggest city of Russian Federation in the region located just in the delta of Volga River, thus being a potential gateway of introductions to the Caspian Sea and adjacent freshwaters. The local pet trade involves 12 NICS. Considering their origin, availability, probability of establishment, invasiveness and further aspects, Procambarus fallax f. virginalis, P. clarkii and Cherax destructor are considered potentially the most problematic, including transmission of diseases like crayfish plague caused by Aphanomyces astaci or white spot syndrome virus. Taking this information as a whole, the availability of NICS with a high probability of overlapping the entire range of European ICS means that attention is warranted. Further research is needed to corroborate the abilities of NICS and their associated diseases to withstand specific conditions of the Caspian Sea as well as the adjacent Black and Azov Seas, all possessing different degrees of elevated salinity.     

Molecular Phylogeny of Grey Mullets (Teleostei: Mugilidae) in Greece: Evidence from Sequence Analysis of mtDNA Segments

Mitochondrial DNA sequence analysis has been used to explore genetic differentiation and phylogenetic relationships among five species of the Mugilidae family, Mugil cephalus, Chelon labrosus, Liza aurata, Liza ramada, and Liza saliens. DNA was isolated from samples originating from the Messolongi Lagoon in Greece. Three mtDNA segments (12s rRNA, 16s rRNA, and CO I) were PCR amplified and sequenced. Sequencing analysis revealed that the greatest genetic differentiation was observed between M. cephalus and all the other species studied, while C. labrosus and L. aurata were the closest taxa. Dendrograms obtained by the neighbor-joining method and Bayesian inference analysis exhibited the same topology. According to this topology, M. cephalus is the most distinct species and the remaining taxa are clustered together, with C. labrosus and L. aurata forming a single group. The latter result brings into question the monophyletic origin of the genus Liza.     

Species composition and distribution of Zoarcidae in the northern part of the Sea of Japan from the data of trawl surveys

Species composition, ratio, distribution, and size composition of Zoarcidae on the shelf and the upper part of the continental slope of the northern part of Japan at depths of 5 to 700 m were analyzed on the basis of four trawl surveys. In the studied area, nine species of Zoarcidae were found: Bilabria sp., Bothrocara hollandi, Davidijordania lacertina, Lycodes japonicus, L. nakamurae, L. cf. yamatoi, L. tanakae, L. toyamensis, and L. cf. ushakovi. Data on catches, density of distribution at different depths, and size composition are listed for each species. Four species: B. hollandi, L. tanakae, L. nakamurae, and L. cf. yamatoi have the greatest biomass and numbers among zoarcids in the northern part of the Sea of Japan. It was shown that zoarcids from the northern part of the Sea of Japan, similar to most demersal fish, perform seasonal migrations from the depths of 200 to 500 m, which they inhabit in the summer period, to depths larger than 400 m in the winter. It was found that the most common species of Zoarcidae (B. hollandi, L. tanakae, L. nakamurae, L. cf. yamatoi, and L. toyamensis) dwell mainly in waters of the intermediate water mass and the upper part of the Sea of Japan water mass. These species are abundant at depths larger than 200 m, which permits assigning them to a mesobenthal ecological group. All of the studied species of Zoarcidae from the given region are stenothermal—the temperature range of their habitation is below 2°C, as a rule, from 0.3 to 2.5°C.     

Fish Scales as Potential Substrate for Production of Alkaline Protease and Amino Acid Rich Aqua Hydrolyzate by <Emphasis Type="Italic">Bacillus altitudinis</Emphasis> GVC11

Fish processing industries generate large quantities of fish scales as processing waste, if not treated leading to environmental pollution. Fish scales are hard to degrade, hence cause difficulty in waste management. In this context present study was made to utilize fish scales as substrate for the production of alkaline protease by Bacillus altitudinis GVC11 and subsequently amino acid rich aqua hydrolyzate. B. altitudinis GVC11 efficiently utilized five types of fish scales as substrates and produced maximum alkaline protease using Labeo rohita (28,150 U/mL) followed by Catla catla (23,320 U/mL) at 48 h and Cyprinus carpio (17,146 U/mL) Mugil cephalus (18,917 U/mL), Cirrhinus mrigala (12,430 U/mL) at 72 h. The HPLC analysis of protein hydrolyzate obtained after fermentation was enriched in essential amino acids, leucine, isoleucine, phenylalanine, lysine and non-essential amino acids, tyrosine, arginine and cysteine which can be used as animal feed supplement and organic fertilizer.     

Fish production in estuaries of Primorye

Production of fish communities in 15 different-types estuaries was assessed based on the data collected as a result of 90 surveys (860 seine stations) conducted in Primorye in 2002–2015. The main contribution to production was made by semi-anadromous species (the so-iuy mullet Liza haematocheilus, Far Eastern redfins Tribolodon spp., and Japanese smelt Hypomesus nipponensis, etc.). In both external (EP _ext) and internal (EP _int) polyhaline estuaries (EP) a substantial portion of the production was provided by resident marine species (mainly by the saffron cod Eleginus gracilis, Far Eastern smooth flounder Liopsetta pinnifasciata, and tidepool gunnel Pholis nebulosa) and southern immigrants (flathead grey mullet Mugil cephalus, dotted gizzard shad Konosirus punctatus, Japanese halfbeak Hyporhamphus sajori, and Pacific needlefish Strongylura anastomella). In mesohaline (EM) and oligohaline (EO) estuaries, the proportion of marine residents and southern immigrants was reduced to a minimum, while that of freshwater species (bighead gudgeon Gobio macrocephalus, Prussian carp Carassius gibelio, minnow Phoxinus spp., Amur bitterling Rhodeus sericeus, spiny bitterlings Acanthorhodeus spp., etc.) substantially added to the production of semi-anadromous fish. The mean fish biomass for the vegetation season varied in the 143–1463 mgC/m² range; the mean annual production was 174–4267 mgC/m² and the mean P/B ratio was 0.2–3.2. In 2007, the high annual production in the Artemovka River estuary, 9356 mgC/m², was formed by the juvenile so-iuy mullet of the strong yearclass that hatched in 2006. The lowest mean production and P/B values were typical mainly for the water bodies with a salinity more often close to that of the barrier zones (5–8‰ for α-horohalinicum and 22–26‰ for β-horohalinicum), i.e., for EM and EP _ext. This relationship is explained by the features of the osmotic regulation in fish of various origins and its ontogenetic variations. In particularly, the salinity in EM is more frequently close to the critical salinity (5–8‰, α-horohalinicum); thus, the proportion of juveniles of most of the species in the catches decreases (as their resistance to salinity variations is lower). This results in higher mean values of the specific and absolute production of fish communities in EP _int and EO as compared to those in EM. The conclusion was made that the estimates of fish production in the estuaries of Primorye are similar to those in the well-studied estuaries of the temperate, subtropical, and tropical zones. Moreover, they are comparable to the fish production estimates for mesotrophic and eutrophic lakes in northwestern Russia, substantially lower than those for large lowland rivers, and higher than those for small rivers. The fish production in seas, including the Japan/East Sea (0.20 gC/m²) and, particularly, Peter the Great Bay (0.28 gC/m²), is mostly lower than that in Primorye estuaries.     

Morphological variability,chromosome polymorphism,and problems of identifying individual species of gobies of the group <Emphasis Type="Italic">Ponticola</Emphasis> (Gobiidae) and assessing taxonomic relations of local populations

In connection with the problems of identification of certain species of the genus Ponticola, and especially their juveniles, morphological and genetic studies of gobies collected in the northwestern part of the Black Sea basin were carried out using literature data and museum collections. Karyological data indicate a distinct species status of western (P. odessicus) and eastern (P. eurycephalus) mushroom gobies; the range of the latter includes not only the Sea of Azov but also waters of the Black Sea coast of the Crimean Peninsula; these conclusions are supported by preliminary molecular genetic studies. Based on the obtained results of intraspecific morphological variability of species, we propose morphological characteristics for identification of adult P. syrman and P. odessicus, as well as a specific set of characteristics to identify juvenile (body length less than 50 mm) P. syrman, P. kessleri, and P. odessicus. We reveal differences in the karyotype structure of P. syrman from populations of the Sasyk Lake and the Don River, which do not differ in terms of external morphological characteristics and variability of cytochrome b haplotypes. The need for further research of phylogeography and morphological and karyological variability of P. syrman sensu lato is assumed.     

Phylogenetic relationships of Sakhalin taimen <Emphasis Type="Italic">Parahucho perryi</Emphasis> inferred from PCR-RFLP analysis of mitochondrial DNA

RFLP analysis of three amplified mtDNA fragments (Cytb/D-loop, ND1/ND2, and ND3/ND4L/ND4) was performed in the following taxa: Parahucho perryi, Hucho taimen, Brachymystax lenok, B. tumensis, Salmo salar, Salvelinus leucomaenis, and S. levanidovi. For mtDNA of P. perryi, a substantial decrease in the haplotype and nucleotide diversity was observed as a result of random genetic drift, caused by a reduction in the effective population size. Nucleotide divergence estimates between the mtDNA haplotypes were determined. Sakhalin taimen P. perryi was found to be approximately equally diverged from S. salar and from the charrs of the genus Salvelinus, by 11.0 and 10.0%, respectively. The divergence between P. perryi and H. taimen constituted 14.6%, between P. perryi and lenoks of the genus Brachymystax, 14.2%, and between H. taimen and Brachymystax, 7.7%. The analysis of possible phylogenetic relationships of the mtDNA from P. perryi among the group of taxa examined confirmed validity of the genus Parahucho. Phylogenetic reconstructions performed showed that robustness of the trees constructed for the complex of phylogenetically informative characters over three mtDNA fragments was considerably higher than that of the trees constructed for individual genes.     

Selenate reduction rates and kinetics across depth in littoral sediment of the Salton Sea,California

To predict selenium cycling in sediments, it is crucial to identify and quantify the processes leading to selenium sequestration in sediments. More specifically, it is essential to obtain environmentally-relevant kinetic parameters for selenium reduction and information on how they spatially vary in sediments. The Salton Sea (California, USA) is an ideal model system to examine selenium processes in sediments due to its semi-enclosed conditions and increasing selenium concentration over the last century. Selenium enters the Salton Sea mainly as selenate and might be sequestered in the sediment through microbial reduction. To determine the potential selenium sequestration of Salton Sea littoral sediments and which sediment properties are controlling selenate reduction kinetics, we determined the centimeter-scale vertical distribution of potential selenate reduction rates and apparent kinetic parameters (maximum selenate reduction rates, V_max, and selenate half-saturation concentration, K_m) using flow-through reactor (FTR) experiments. We compared sediments from two littoral sites (South and North) and four depth intervals (0–2, 2–4, 4–6 and 6–8 cm). Furthermore, we characterized the selenium fractions in the sediment recovered from the FTR experiments to identify the processes leading to the sequestration of selenium. Our results reveal higher potential for selenium reduction and sequestration in the topmost sediment (0–2 cm) suggesting that microorganisms inhabiting surface sediment are well adapted to reduce selenate entering the Salton Sea. As apparent K_m values (103–2144 µM) exceed the average selenium concentration in the overlying water (6–25 nM), in situ selenate reduction is limited by the low availability of selenate and the resident selenate-reducing microorganisms operate well below their V_max (11 and 43 nmol cm^?3 h^?1). Selenium speciation after FTR experiments confirms the primary sequestration of reduced biomass-associated and elemental selenium (68–99% of total selenium) in the sediment. Further, the absence of correlation between the tested sediment physical (porosity, bulk density, clay content), chemical (C_org, N_tot, total selenium content) and biological characteristics (abundance of culturable selenate-reducers) with the kinetic parameters of selenate reduction indicates that these sediment characteristics cannot be used as predictors of apparent V_max or K_m. Conclusively, microbial selenate reduction is an important, if not the primary process, leading to the sequestration of reduced selenium in the Salton Sea sediments and making the surficial Salton Sea sediments an important selenium sink.     

Mollusks of the Utlyuk Liman (Sea of Azov): A Review of Species Composition with Remarks on Distribution and Ecology

Summarized data on the fauna composition, distribution, and ecology of gastropod and bivalve mollusks of the Utlyuk Liman in the northwestern part of the Sea of Azov is presented. The total number of mollusk species identified was 63; 43 species belonged to the class Gastropoda, and 20 species, to the class Bivalvia. The distribution of mollusks in the liman has extremely irregular character, whereas the distribution of species along the marine shore of Biryuchii Ostrov spit is more homogeneous. Euryhaline Mediterranean species represent the core of liman malacofauna; some taxa of the Ponto-Caspian zoogeographical complex (Dreissena polymorpha and species of the genus Theodoxus) and invader species from distant sea basins (Mya arenaria and Anadara inaequivalvis) were also identified.     

<Emphasis Type="Italic">Mirabilicoxa kussakini</Emphasis> sp. nov., a new species of Desmosomatidae (Crustacea,Isopoda, Asellota) from the Sea of Japan

Mirabilicoxa kussakini sp. nov. is described from the bathyal of the northwestern Sea of Japan. This is the first record of the genus Mirabilicoxa Hessler, 1970 in the Sea of Japan. The new species is most similar to M. similis (Hansen, 1916), M. plana Hessler, 1970 and M. minuta Hessler, 1970 from the Northwest Atlantic. It differs from them in having a more elongated body (4.1–4.5 times as long as wide) and antenna 1 with the terminal article 5 shorter than article 4.     

Diagnostic features and taxonomy of the Mediterranean species of the big-scale sand smelts belonging to <Emphasis Type="Italic">Atherina boyeri</Emphasis> group (Atherinidae)

Morphological studies of the big-scale sand smelt from the group Atherina boyeri sensu lato were carried out using the materials of the museum collections from the Mediterranean Sea, the Black Sea, and the Sea of Azov. It has been shown that low-raker sand smelt belonging to the species A. boyeri sensu stricto, and multi-raker sand smelt, referred to the A. mochon species, are differentiated by a complex of morphological features: the number of gill rakers, the shape of scales, the length of the ascending process of praemaxillare, and the shape of the lower margin of maxillare. The key for their identification is presented. It is assumed that A. mochon is not a native Black Sea species but belongs to the invasive species originating from the Mediterranean Sea. The isolation of two cryptic species is discussed. The neotype of A. pontica is designated.     

Differentiation and allozyme variability of shads genus alosa (Clupeiformes,Alosiinae) from Azov-Black Sea basin

Biochemical genetic marking of Sea of Azov-Black Sea shads (Alosa immaculata, A. caspia, and A. maeotica) of three local stocks—Danube, Dnepr, and Azov—was performed based on an analysis of 19 enzyme loci and a series of loci coding muscle structural proteins. The high degree of monomorphism and the absence of any differences in the allele pools are shown, thus confirming their conspecificity. It seems that Caspian, Brazhnikov, and Pontic shads are only morphologically discrete forms and their species rank is unjustified. In truth, they are local and migratory ecomorphs that are almost always present in anadromous fish species.