Morphobiological features of the flathead sculpin Megalocottus platycephalus taeniopterus (Kner) (Scorpaeniformes, Cottidae) from Sakhalin

Data on the flathead sculpin Megalocottus platycephalus taeniopterus from different regions of Sakhalin are provided. Based on analysis of the morphological material, the estimates of taxonomically significant characters of the northern and southern subspecies are clarified. They include the relative length of the lower jaw, the extent of development of postorbital and occipital tubers, the coloration of pectoral fins, the shape of free ends of ventral fin rays, and their relative length and coloration in females. The habitats of M. platycephalus taeniopterus are considerably attributed to the desalinated sites of coastal waters. In the areas of eastern Sakhalin, its individuals stay in brackish water lakes and lagoons for a considerable part of their life; some individuals migrate to coastal waters for feeding in summer. Considerable differences are observed between populations in the life span, rate of growth, and the age of maturation of individuals. In the regions of eastern and western Sakhalin, the pattern of feeding of M. platycephalus taeniopterus differs considerably: in eastern regions, it is a clearly pronounced predator, and in western regions, it feeds mainly on invertebrates.     

Age and growth analysis of the mosshead sculpin Clinocottus globiceps Girard 1857 (Pisces: Cottidae) from Helby Island, British Columbia

The age and growth of the cottid fish Clinocottus globiceps Girard from tidepools at Helby Island, British Columbia, Canada were investigated with the aid of whole saccular otoliths (sagittae); ages were validated by marginal increment analysis. Four hundred and twenty five specimens were examined from 214 females and 211 males. Marginal increment analysis on specimens with one to three opaque zones suggested an annual ring deposition in sagittae during the late autumn and spring months.
The C. globiceps population was composed of individuals from less than 1 year to 5 years of age for fish measuring between 5–120 mm standard length. Growth was faster for younger than for older age groups. Lengths-at-age data were fitted to the Gompertz growth model, and estimates of the model parameters L₀, G and g were 26.7 mm 1.58 and 0.30 for pooled cohorts, respectively. The highest levels of growth occurred during late spring and early summer, when water temperatures were at maximum and food was most abundant. The lowest levels of growth occurred during the autumn and winter months.     

A new species of sculpin,Icelus ecornis (Scorpaeniformes: Cottidae) from the southwestern Okhotsk Sea

A new cottid species,Icelus ecornis, is described on the basis of 31 specimens collected from 159–226 m in the southwestern Okhotsk Sea off Hokkaido, Japan. It is distinguished from all other members of the genusIcelus by the following combination of characters: no supraocular and parietal spines; short blunt nuchal spine; cirri absent from head and body, except for supraocular, parietal and nuchal regions; platelike scales of dorsal row bearing 6–10 long uniform spinules; tubular lateral line scales bearing small spines on dorsal and posterior margins; large oval black spot on first dorsal fin; 16–20 anal fin rays.     

Patch selection by mottled sculpin (Pisces: Cottidae) in a southern Appalachian stream

1. We examined the effects of prey abundance on patch selection by a benthic fish, the mottled sculpin ( Cottus bairdi ), in a fourth order, southern Appalachian stream (North Carolina, U.S.A.). This habitat is a mosaic of small (i.e. < 0.5 m²), relatively discrete patches.
2. Patches were characterized in terms of physical habitat variables, detritus (coarse particulate organic matter, CPOM) and macroinvertebrate abundance (number and biomass). We quantified patch selection by comparing the characteristics of patches utilized by sculpin with those of locally available patches. Locally available patches were selected using a constrained random sampling design (i.e. randomly selected within a 2 m radius from each fish). We also examined the relationship between macroinvertebrate abundance, CPOM and the physical characteristics of available patches.
3. Patches selected by sculpin contained significantly higher macroinvertebrate abundances (both number and biomass) than locally available patches in five out of six seasonal samples. Sculpin also occupied patches with significantly higher amounts of CPOM in three out of five seasonal samples. Patches utilized by sculpin, however, could not be consistently differentiated from locally available patches on the basis of physical variables. In addition, macroinvertebrate abundance was not consistently related to physical habitat variables or CPOM during the course of the study.
4. Our results suggest that sculpin are able to assess patch quality on the basis of prey abundance and select patches that potentially maximize energy gain. This behaviour may produce an increase in individual fitness, especially when prey distributions are not consistently related to habitat variables. Quantifying patch use in relation to prey abundance may help elucidate the causal factors determining habitat use by benthic fishes in other lotic systems.     

Patch selection by mottled sculpin (Pisces: Cottidae) in a southern Appalachian stream

1. We examined the effects of prey abundance on patch selection by a benthic fish, the mottled sculpin ( Cottus bairdi ), in a fourth order, southern Appalachian stream (North Carolina, U.S.A.). This habitat is a mosaic of small (i.e. < 0.5 m²), relatively discrete patches.
2. Patches were characterized in terms of physical habitat variables, detritus (coarse particulate organic matter, CPOM) and macroinvertebrate abundance (number and biomass). We quantified patch selection by comparing the characteristics of patches utilized by sculpin with those of locally available patches. Locally available patches were selected using a constrained random sampling design (i.e. randomly selected within a 2 m radius from each fish). We also examined the relationship between macroinvertebrate abundance, CPOM and the physical characteristics of available patches.
3. Patches selected by sculpin contained significantly higher macroinvertebrate abundances (both number and biomass) than locally available patches in five out of six seasonal samples. Sculpin also occupied patches with significantly higher amounts of CPOM in three out of five seasonal samples. Patches utilized by sculpin, however, could not be consistently differentiated from locally available patches on the basis of physical variables. In addition, macroinvertebrate abundance was not consistently related to physical habitat variables or CPOM during the course of the study.
4. Our results suggest that sculpin are able to assess patch quality on the basis of prey abundance and select patches that potentially maximize energy gain. This behaviour may produce an increase in individual fitness, especially when prey distributions are not consistently related to habitat variables. Quantifying patch use in relation to prey abundance may help elucidate the causal factors determining habitat use by benthic fishes in other lotic systems.     

The karyotype of the flathead sculpin Megalocottus platycephalus platycephalus (Pallas, 1814) (Pisces: Cottidae) from Odyan Bay,Sea of Okhotsk

This study deals with the karyotype of the flathead sculpin Megalocottus platycephalus platycephalus (Pallas, 1814) (family Cottidae) from Odyan Bay of the Sea of Okhotsk. The karyotype is stable: 2n = 42 (2 metacentric, 2 submeta-subtelocentric, 30 subtelocentric, and 8 acrocentric chromosomes), NF = 44 + 2. The nucleolar organizers (NOs) were identified using Ag-banding in the telomere parts of the short arms of two large subtelocentric chromosomes. Variations in the number of nucleolar organizer chromosomes and in the number of NO-staining blocks were found. Comparison of the karyotype of M. p. platycephalus with the karyotypes of previously studied species of the genus Myoxocephalus from the Sea of Japan and the Sea of Okhotsk revealed their significant similarity in the main features and difference in the number and localization of NORs.     

The Karyotype of the flathead sculpin Megalocottus platycephalus taeniopterus (Kner, 1868) (Pisces: Cottidae) from Vostok Bay,Sea of Japan

For the first time, we studied the karyotype of the flathead sculpin Megalocottus platycephalus taeniopterus (Kner, 1868) from Vostok Bay of the Sea of Japan. The karyotype is stable: 2n = 42 (2 metacentric, 2 submeta-subtelocentric, 30 subtelocentric, and 8 acrocentric chromosomes), NF = 44 + 2. The nucleolar organizers (NOs) were identified using Ag banding in two pairs of chromosomes: in the telomeric parts of the short arm of the medium-size subtelocentric chromosome and the long arm of the large acrocentric chromosome. Variations in the number of nucleolar organizer chromosomes and in the number of NO staining blocks were found. Comparison of the karyotypes of M. p. taeniopterus and previously studied M. p. platycephalus (Pallas, 1814) from the northern Sea of Okhotsk revealed their similarity in the number and morphology of chromosomes and the number of chromosome arms and difference between the subspecies in the number and location of NO, which allows their discrimination.     

A new sculpin species Cottus sabaudicus sp. nova (Scorpaeniformes: Cottidae) from the Savoy district, France

Sculpins from mountain tributaries of the upper reaches of the Rhone River (Haute-Savoy district) in the collection of the National Museum of Natural History (Paris, France) are described as a new species Cottus sabaudicus. This species belongs to the species group C. gobio, but is characterized by several morphologically specific features. It differs from the typical species of the genus C. gobio in its monotonous body coloration, an increased postanal distance that equals preanal distance, an absence of dark stripes on ventral fins, the ratio of the length of caudal peduncle and depth (1.8–2.3 versus 2.3–2.8), and a greater number of pores in the trunk seismosensory canal (34–37 versus 31–33 + 1).     

Fossil Wolffish (Anarhichadidae) From the Miocene Deposits of Sakhalin Island

Journal of Ichthyology - In the deposits of the Middle–Late Miocene of the deep-water Kurasi Formation of Southwestern Sakhalin, a destroyed skeleton of the wolffish head Anarhichadidae gen....     

A new species of sculpin Cottus kolymensis sp. nova (Scorpaeniformes, Cottidae) from Rivers of Kolyma

Sculpin from the Kolyma, Dukcha, and Glukhaya rivers is described as a new species Cottus kolymensis from the species group ??Cottus poecilopus??. This species differs from the remaining species of the group (C. altaicus, C. szanaga, C. kuznetzovi, C. koreanus, and C. volki) in the combination of several characteristics: very short internal ray of ventral fin averaging 1/5 of the long ray; comparatively wide interorbital space equal or slightly smaller than longitudinal eye diameter, presence of teeth on palatine bones; as a rule, paired fifth pore of the preoperculo-mandibular canal; and an incomplete lateral canal terminating in two to three autonomous segments and opening by (13 + 2 + 2)-(23 + 2 + 2 + 2) pores.     

Comparative analysis of the karyotype of the sculpin Myoxocephalus ochotensis (Pisces: Cottidae) from the Odyan Bay of the Sea of Okhotsk

The karyotype of the endemic Okhotsk Sea sculpin Myoxocephalus ochotensis Schmidt (Cottidae) from Odyan Bay was studied. The number and morphology of chromosomes were determined, 2n = 42 (2 metacentric, 20 subtelocentric, and 20 acrocentric chromosomes), NF = 44. Variability of chromosome number was not revealed; no difference between male and female karyotypes was found. The karyotype of the Okhotsk sculpin M. ochotensis was compared with karyotypes of the Far East Steller’s M. stelleri (Tilesius), snow M. brandti (Steindachner), and plain M. jaok (Cuvier) sculpins, and to the European shorthorn sculpin M. scorpius (Linnaeus) from White Sea. Their similarities and distinctions were shown.     

A Fossil Melamphaid Fish of the Genus Scopelogadus (Teleostei: Melamphaidae) from the Neogene Deposits of Sakhalin Island,Russia

Paleontological Journal - The skeleton of a berycomorph fish of the Melamphaidae family was found in sediments of the Middle-Upper Miocene of the Kurasi Formation of Sakhalin Island, Russia....     

A new species of the genus Hypsibius (Tardigrada: Parachela: Hypsibiidae) from Sakhalin island, far East Russia

A new species of semiterrestrial eutardigrade, Hypsibius stiliferus, is described from Sakhalin Island, Far East Russia. The new species is distinguished from its congeners by having an irregular, polygonal or subtriangular dorsal sculpture, which increases in size posteriorly, two granular macroplacoids, and a cuticular bar near the base of posterior claw 4, and by lacking a microplacoid and septulum. It is currently known from its type locality and several other localities in northern and southern Sakhalin Island. This is the first report concerning tardigrades from Sakhalin Island.     

A new pachyosteomorph arthrodire (Pisces: Placodermi) from the Upper Frasnian of the Central Devonian Field,Russia

A new genus and species of pachyosteomorph arthrodire, Omalosteus krutoensis gen. et sp. nov. from shallow-water marine deposits of the Evlanovo Regional Stage (Upper Frasnian, Upper Devonian) of the Central Devonian Field is described. It is tentatively referred to the family Trematosteidae Gross, 1932, which was earlier believed to be endemic to central Europe. The new genus is characterized by a rounded, dorsoventrally compressed cross section of the pectoral region and smooth head shield and postcranial membrane bones. The centrale is elongated, forming a narrow lateral lobe. The praeorbitale, postorbitale, and centrale come in contact in the center of the orbital region. The mediodorsale is wide, its carinal process projects considerably posteriorly. The anterior margin of the anterior ventrolaterale lacks articular facets for the interlaterale.     

Embryonic, larval and juvenile development of the roughskin sculpin,Trachidermus fasciatus (Scorpaeniformes: Cottidae)

Embryonic, larval and juvenile development of the catadromous roughskin sculpin,Trachidermus fasciatus, were described using eggs spawned in an aquarium. The eggs, measuring 1.98–2.21 mm in diameter, were light reddish-yellow and had many oil globules, 0.05–0.18 mm in diameter. Hatching occurred 30 days after spawning at 2.3–11.3°C. The newly-hatched larvae, measuring 6.9–7.3 mm BL, had a single oil globule, 9–10+25–26=34–36 myomeres and 6 or 7 large stellate melanophores dorsally along the gut. The yolk was almost resorbed, number of pectoral-fin rays attained 16–17, and two parietal, one nuchal and four preopercular spines were formed, 5 days after hatching, at 8.2–8.4 mm BL. The oil globule disappeared, and one supracleithral spine was formed, 11 days after hatching, at 8.9–9.5 mm BL. Notochord flexion began 15 days after hatching, at 9.7–10.3 mm BL. A posttemporal spine was formed 20 days after hatching, at 10.7–10.9 mm BL. The first dorsal fin spines (VII–VIII), second dorsal fin and anal fin rays (18–19, 16–18, respectively) appeared 23 days after hatching, at 12.0–13.7 mm BL. The pelvic fin spine and rays (I, 4) were formed and black bands on the head and sides of the body began to develop 27 days after hatching, at 13.8–15.8 mm BL. Newly-hatched larvae swam just below the surface in the aquaria. Preflexion larvae (8.9–9.5 mm BL), in which the oil globule had disappeared, swam in the middle layer, while juveniles (13.8–15.8 mm BL) began swimming on the bottom of the aquaria. Swimming behavior observed in the aquaria suggested that the fish started to change to a demersal existence at the juvenile stage.     

A dragonet (Perciformes: Callionymidae) from the Middle Miocene of southern Russia

From the Middle Miocene (Konkian) deposits in the Taman Peninsula, a new genus and species of dragonets Protonymus gontsharovae gen. et sp. nov. are described, differing from all known recent and fossil members of the family in the structure of the preopercular spine, radialia of pectoral fins, and of otolith (sagitta). The history of dispersal of dragonets in the Paleogene-Neogene is discussed.     

Non-indigenous amphidromous sculpin Cottus pollux small-egg type (Teleostei: Cottidae) detected in rivers entering the Sea of Japan off Honshu Island, Japan

The amphidromous sculpin Cottus pollux small-egg type (SE) is an endemic species in rivers that flow into the Pacific Ocean on the east side of Honshu Island, Japan. However, our molecular genetic and morphological analyses using recently collected specimens showed that C. pollux SE inhabits some rivers flowing into the Sea of Japan, where this species is originally non-indigenous. Thus, these results suggest that C. pollux SE was anthropogenically introduced into these rivers. In addition, our data on the size distribution of juvenile fishes suggest that non-indigenous C. pollux SE reproduce at least in rivers of Ishikawa Prefecture.