Summer-autumn ichthyoplankton of the Sea of Okhotsk and the Sea of Japan and special traits of feeding of fish larvae and fry in 2003–2004

In summer-autumn of 2003–2004, the ichthyoplankton of the Sea of Okhotsk comprised 35 species. In this period the most widely distributed and numerous were larvae of the lord Hemilepidotus gilberti, the Pacific stout sand lance Ammodytes hexapterus, and the Sakhalin dab Limanda sakhalinensis. The maximum catches of fish larvae were attributed to coastal waters off eastern Sakhalin and to the shelf of the northern part of the Sea of Okhotsk. In November of 2003, the ichthyoplankton of the Sea of Japan was represented by fish larvae belonging mainly to the boreal ichthyocomplex. The catches consisted predominantly of larvae of the arabesque greenling Pleurogrammus azonus, the ronquil Bathymaster derjugini, and the rockfish Sebastes owstoni. Fish larvae and fry in the northwestern part of the Sea of Japan were caught principally within 43°–45° N and 137°–139° E above the depth 1500–2000 m. The food spectrum of fish larvae in the Sea of Okhotsk and the Sea of Japan comprised over 20 plankters of various size belonging to seven taxa. Irrespective of fish species, the food items common of all fish were copepods Pseudocalanus minutus and Oithona similis. The daily rations were calculated for mass species (Hemilepidotus gilberti, Ammodytes hexapterus, Hexagrammos stelleri, Pleurogrammus azonus, Bathymaster derjugini, and Sebastes owstoni). The larvae of all considered species in the Sea of Japan and in the Sea of Okhotsk fed predominantly in the light period of the day.     

<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.     

Review of the genus <Emphasis Type="Italic">Banjos</Emphasis> (Perciformes: Banjosidae) with descriptions of two new species and a new subspecies

A taxonomic review of the genus Banjos (Perciformes: Banjosidae), previously restricted to a single species, Banjos banjos (Richardson 1846), recorded from the northwestern Pacific Ocean from the South China Sea north to Japan, as well as Lombok (Indonesia), New Caledonia and Australia, resulted in the recognition of three species, including B. banjos (northwestern Pacific Ocean, Indonesia and western Australia), Banjos aculeatus sp. nov. (eastern Australia) and Banjos peregrinus sp. nov. [northern Australia (Timor Sea)]. Records of B. banjos from New Caledonia probably also represent B. aculeatus, which is clearly distinct from other congeners in having a relatively long, strongly serrated spine at the posteroventral angle of the preopercle and an entirely dusky membrane on the spinous dorsal fin in juveniles < ca. 70 mm SL, in addition to slightly longer first and second dorsal-fin spines. Banjos peregrinus is characterized by a relatively greater head length, orbit diameter, postorbital length and pre-pelvic-fin length, as well as poorly developed serration of the exposed margin of the cleithrum. Within B. banjos, a population from the southeastern Indian Ocean, including Indonesia and western Australia, is regarded as a distinct subspecies (Banjos banjos brevispinis ssp. nov.), distinguishable from B. b. banjos from the northwestern Pacific Ocean by a relatively narrow least interorbital width, and shorter second and eighth dorsal-fin spines. Ontogenetic morphological changes within the genus and the status of the holotype of Anoplus banjos Richardson 1846 are discussed in detail.     

The species composition,morphology, and seasonal distribution of diatoms of the genus <Emphasis Type="Italic">Attheya</Emphasis> West, 1860 from the Sea of Japan

Six species that belong to the diatom genus Attheya were found in the Russian waters of the Sea of Japan. A. cf. flexuosa is a new record for the seas of Russia. A. decora is recorded for the first time for the Sea of Japan. The peculiarities of the morphology of A. decora and A. cf. flexuosa are described and illustrated. The study of the seasonal distribution, abundance, and ecology of Attheya species in the northwestern Sea of Japan showed that A. longicornis and A. ussurensis were the most numerous and widespread species, reaching maximum densities (up to 1.5 × 10⁶ and 1.8 × 10⁴ cells/liter, respectively) in the spring, summer, and fall. A. cf. flexuosa and A. septentrionalis were rare and were found in low numbers in the winter and early spring. Based on the ultrastructure of the girdle bands, the form and number of chloroplasts, the presence/absence of rimoportula on the valve, and habitat features, we distinguished two groups of species of the genus Attheya from the Sea of Japan. The first group includes psammophytes A. decora, A. arenicola, and A. ussurensis; the second one comprises A. longicornis and A. cf. flexuosa epiphytic on other diatoms, as well as A. septentrionalis, which is found in the under-ice plankton and is able to attach to the underside of ice.     

On catches of low-latitude fish at Sakhalin coast in summer 2014

In summer 2014, catches of three tropical and subtropical fish species were registered at Sakhalin coast. The Japanese sea bass Lateolabrax japonicus was detected at Sakhalin coast for the first time, while the Japanese amberjack Seriola quinqueradiata was first detected in the Sea of Okhotsk waters sweeping the Sakhalin coast. The catch of the great white shark Carcharodon carcharias is the second confirmed case of this fish occurrence near the Sakhalin coast for the last 10 years.     

Mitochondrial DNA divergence and phylogenetic relationships in mullets (Pisces: Mugilidae) of the Sea of Japan and the Sea of Azov revealed by PCR-RFLP-analysis

Three Mugilid species: Mugil cephalus (Linnaeus, 1758) and Liza haematocheila (Temminck et Schlegel, 1845; syn. Mugil soiuy, M. haematocheilus, L. soiuy, Chelon haematocheilus) from the Sea of Japan, as well as M. cephalus and Liza aurata (Risso, 1810) from the Sea of Azov were investigated on the basis of PCR-RFLP analysis of mitochondrial DNA (mtDNA) fragments, which included 12S/16S rRNA, and ND3/ND4L/ND4 genes. Among 61 individuals of three Mugilid species thirteen different haplotypes were detected. Eight and thirteen restriction endonucleases were found to be species-specific in 12S/16SrRNA and ND3/ND4L/ND4 respectively. This method may be useful for species identification. M. cephalus showed the largest genetic divergence while L. haematocheila and L. aurata were closely related and clustered together. The level of mtDNA differentiation between the two M. cephalus samples from the Sea of Japan and the Sea of Azov, i.e., nucleotide substitutions of approximately 3%, appeared to be relatively high.     

Systematics and biology of the East Siberian char <Emphasis Type="Italic">Salvelinus leucomaenis</Emphasis>

A review that considers in detail for the first time the taxonomic position, phenetic diversity, and principal features of the endemic species East Siberian char Salvelinus leucomaenis in the range from the northeast of Asia to Japan based on own and published data is provided. In comparison with other species of chars, S. leucomaenis is characterized by a smaller morphological and ecological diversity. A migratory form feeding on fish is dominant in the range. At the same time, parallel to large migratory forms, other life forms—resident riverine and lacustrine-riverine forms represented by males and females and riverine and dwarf males were found in S. leucomaenis. Individuals with various color variations occur everywhere. Resident forms are rare in the north of the range; they are dominant in the south of the range, in Japan.     

Reproduction and development of <Emphasis Type="Italic">Pholis picta</Emphasis> (Perciformes: Pholidae) and <Emphasis Type="Italic">Opisthocentrus zonope</Emphasis> (Stichaeidae)

In the Peter the Great Bay (the Sea of Japan), reproduction and embryonic larval development of Pholis picta and Opisthocentrus zonope are investigated. Both species spawn in November–December at the water temperature decreasing from 7.0 to 0.2°C. Fecundity of Pholis picta is 494–1228 eggs, and of Opisthocentrus zonope—368–1360 eggs. Both species lay eggs in empty shells of Gray mussel. Parent fish permanently stay in the shell but do not actively care for the eggs. Morphological changes in the process of embryogenesis are compared between the related species. Prolarvae and larvae are described for identification, with special attention to pigmentation. The spawning behavior of adult fish and behavior of prolarvae are described.     

Molecular genetic and karyological analysis of antlered sculpins of <Emphasis Type="Italic">Enophrys diceraus</Emphasis> group (Cottidae)

Molecular genetic and karyological analyses of antlered sculpin, Enophrys diceraus, from the Sea of Japan and the Sea of Okhotsk were carried out. The karyotype of this species was studied for the first time. On the basis of karyological analysis, it was established that E. diceraus from the Sea of Japan and the Sea of Okhotsk was polymorphic in terms of the number of chromosomes and their morphology (2n = 36, 35, and 37, NF = 40). It was suggested that the karyotype with 35 chromosomes could have been produced as a result of Robertsonian translocation; the karyotype with 37 chromosomes could have been produced by crossing of individuals with different number of chromosomes. On the basis of the molecular genetic analysis of the mitochondrial COI and 16S rRNA genes, considerable differences between E. diceraus from the Sea of Japan and the Sea of Okhotsk corresponding to the level of interspecies genetic variability were established. It is concluded that E. diceraus from the Sea of Japan belongs to another species, most likely, E. namiyei.     

An Annotated List of Cartilaginous Fishes (Chondrichthyes: Elasmobranchii,Holocephali) of the Coastal Waters of Sakhalin Island and the Adjacent Southern Part of the Sea of Okhotsk

An annotated list of cartilaginous fish (Chondrichthyes: Elasmobranchii, Holocephali) is given for the first time in the 200-year history of studying the ichthyofauna of Sakhalin Island and adjacent waters of the southern part of the Sea of Okhotsk (including the coast of Hokkaido Island) and the northern Sea of Japan. The list includes 43 species in two classes, eight orders, 16 families, and 25 genera. Information on nature conservation status, English and Latin names, depths of habitat, and distribution within the coastal waters of Sakhalin are presented. For a number of species caught off the coast of Sakhalin and in the adjacent waters, information is provided on collection specimens confirming their presence in the region under study. For a number of species of the Rajiformes order (Arctoraja parmifera, A. smirnovi, A. simoterus), the modern ranges and taxonomic status are being refined in the light of new data. The taxonomic status of the so-called “disputed” taxa is discussed as well as the validity of the species considered in the Bathyraja matsubarai complex. Based on the study of the collections, Arctoraja simoterus, previously unknown in the waters of Russia, as well as Myliobatis tobijei, caught in the Bering Sea, has been discovered, which significantly expands the range of this species to the north.     

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.     

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.     

Comparative characteristics of the diet of Pacific halibut <Emphasis Type="Italic">Hippoglossus stenolepis</Emphasis> from different areas of the northwestern part of the Pacific Ocean

Food composition of Pacific halibut Hippoglossus stenolepis has been considered in three areas of the northwestern Pacific: in the western part of the Bering Sea, in Pacific waters off the northern Kuril Islands and southeastern Kamchatka, and waters off the southern Kuril Islands. The main food items in all studied regions were shrimp, cephalopods, and fish. It has been noted that fish offal plays a considerable role in the feeding of H. stenolepis in the western part of the Bering Sea. Changes in food composition in relation to fish growth, depth of catch, and sex of individuals have been analyzed; and differences in the composition of food items consumed by H. stenolepis in different parts of the studied areas have been considered.     

Gorgonians (Anthozoa: Octocorallia) of the northwestern Sea of Japan

Three species of gorgonians (Primnoa pacifica, Calcigorgia japonica, and Thouarella superba) are reported as new records for the northwestern Sea of Japan; one of them (Calcigorgia japonica sp. n.) has been described as a new species. Variations of colony morphology in some species are described; the taxonomical value of specific characters is discussed. The geographical range of Primnoa pacifica in the northwestern Pacific is shown to be wider than was considered earlier. Variations of sclerite morphology (number of marginal plates, presence of additional basal plates, and number of marginal spines on the basal plate) are regarded as intracolonial or intraspecific variability. The distribution range of Thouarella superba described earlier from the Aleutian Islands (Nutting, 1912) was shown to extend into the low-boreal part of the boreal Pacific. An examined specimen of Paragorgia sp. differed from all known species and appeared similar only to P. regalis Nutting, 1912 reported from the eastern coast of Japan. The most distinctive characters of Calcigorgia japonica sp. n. were the shape of polyp, with a thin lower part looking like folded podia (in fixed specimens) and the presence of two types of clubs scattered among the sclerites of the polyp.     

Two new species of <Emphasis Type="Italic">Sagum</Emphasis> Wilson, 1913 (Copepoda: Siphonostomatoida: Lernanthropidae) parasitic on reef fishes off the Ryukyu Islands

Two new species of parasitic copepods, Sagum gurukun n. sp. and S. bitaro n. sp. (Siphonostomatoida: Lernanthropidae), are described based on specimens collected from the gill filaments of the double-lined fusilier Pterocaesio digramma (Bleeker) (Actinopterygii: Perciformes: Caesionidae) and the five-lined snapper Lutjanus quinquelineatus (Bloch) (Actinopterygii: Perciformes: Lutjanidae), respectively, caught off Iriomote-jima Island, the Ryukyu Islands, East China Sea, Japan. The findings bring the number of species of Sagum to 14. The two new species are similar in the morphology of the head and the legs 3 and 4 to the three congeners, S. folium Ho, Liu & Liu, 2011, S. paracaesionis Izawa, 2014 and S. vietnamiensis Kazachenko, Kovaleva, Nguyen & Ngo, 2017. Sagum gurukun n. sp. is differentiated from the three congeners by the proportions of the caudal rami, the absence of leg 5, and the shape of the legs 1 and 2. Sagum bitaro n. sp. differs from the three congeners and S. gurukun n. sp. by the presence of the conical leg 5 armed with an apical seta. A key to the species of the genus Sagum, based on the available information on female morphology in previous publications and the present study, is provided. To date, a total of 19 species of lernanthropid copepods considered valid are known in Japanese waters.     

Vertebrates from the Pontian of the Shkodova Gora locality (Northwestern Black Sea Region,Upper Miocene)

Remains of fishes, turtles, birds, and mammals are described from the Upper Miocene (MN13) Shkodova Gora locality (Ukraine, Odessa Region), the only representative locality of Pontian large vertebrates in the northwestern Black Sea Region. Asiatic fish and avian taxa are recorded for the first time in the Upper Miocene of Europe. The Shkodova Gora ichthyofauna includes eight freshwater fish species (belonging to Acipenseridae, Cyprinidae, Siluridae, and Percidae). Taxa that have previously been recorded only in Western Siberia (Abramis bliccoides, Perca lepidopoma), eastern Kazakhstan, and the Altai Mountain (Rutilus tungurukensis) are revealed. Acipenser gueldenstaedtii is recorded for the first time in the Upper Miocene of Eastern Europe. The occurrence of the genus Ctenopharyngodon, a member of the Chinese plain faunal assemblage is of great interest. The Shkodova Gora avifauna (seven taxa) is mostly composed of waterfowl, including Phalacrocorax mongoliensis, which has previously been known only from the Lower Pliocene of Mongolia. The finding of Proanser major is the youngest record of this species in the fossil record. Mammals of the Shkodova Gora association include a hare resembling Trischizolagus dumitrescuae, Palaeoryx cf. pallasi, and Hipparion cf. moldavicum, which have not been mentioned among Pontian taxa of the northern Black Sea Region. Pontian paleolandscapes in the area of the Shkodova Gora locality are reconstructed.