Karyotype of the Snow Sculpin <Emphasis Type="Italic">Myoxocephalus brandti</Emphasis> Steindachner (Cottidae) from Peter the Great Bay,Sea of Japan

The karyotype of the snow sculpin Myoxocephalus brandti, 2n = 44, NF = 46, from Peter the Great Bay was studied. Two-armed chromosomes were presented by one pair of metacentric chromosomes of medium size; one-armed chromosomes included two pairs of large subtelocentric chromosomes and a pair of large acrocentric chromosomes. Ag-NOR-staining in the telomere vicinity revealed nucleolus-organizing regions in one metacentric chromosome and in one medium size acrocentric chromosome in one of the fishes, in two homological small acrocentric chromosomes in three fishes, and in one acrocentric chromosome of average size in six fishes. No difference between the male and female karyotypes and any type of variability was revealed. The karyotypes of the snow sculpin M. brandti and the frog sculpin M. stelleri were compared. Their distinctions and similarities were displayed.Original Russian Text Copyright ¢ 2005 by Biologiya Morya, Ryazanova.     

Environmental influences on seasonal distribution of coastal and estuarine fish assemblages at Wemindji,eastern James Bay

Synopsis The coastal fish assemblages of Wemindji, eastern James Bay, were studied in 1987 and 1988 to describe seasonal utilization of the Maquatua River estuary and the adjacent coastal waters by marine and anadromous fishes. Fish diversity was low (11 sp.) and experimental gill net catches were highly variable between sites in the estuary and coastal waters, and also seasonally at a given site. During summer, the estuarine fishes were numerically dominated by two marine species, the fourhorn sculpin,Myoxocephalus quadricornis, and the slender eelblenny,Lumpenus fabricii, and also by juvenile cisco,Coregonus artedii, and juvenile lake whitefish,C. clupeaformis. In coastal waters, three marine species were abundant: the shorthorn sculpin,M. scorpius, the arctic sculpin,M. scorpioides and the Greenland cod.Gadus ogac. In contrast with the estuary, large (> 270 mm) cisco and lake whitefish were abundant in coastal waters indicating extensive movements of these species in James Bay during the summer. Distribution patterns were influenced by a combination of physical conditions (salinity and temperature) and biological characteristics (habitat choice, migration and reproduction) depending on the season.     

Salinity Tolerance of Some Teleost Fishes of Peter the Great Bay, Sea of Japan

Salinity tolerance in some marine teleost fishes was studied. Based on a comparison of sexually mature specimens in the summer season, the investigated species can be arranged in the order of decreasing capability for hyperosmoregulation into the following series: the Far Eastern dace Trybolodon brandti, the haarder Mugil soiuy > the frog sculpin Myoxocephalus stelleri > the snowy sculpin M. brandti > the plain sculpin M. jaok > the masked greenling Hexagrammos octogrammus > the pipefish Syngnathus acusimilis. The adult Far Eastern dace and the haarder showed high salinity tolerance and fully adapted to fresh water. Sculpins and the masked greenling usually occur only in seas or brackish water, but they were capable of enduring fresh water for a long time. Unlike them, the pipefish, which is also a euryhaline fish and occurs in river estuaries and brackish bays, perished in fresh water within 1 h. Representatives of the genus Myoxocephalus show between-species differences in salinity tolerance, which allows them to colonize extensive near-shore areas of the sea and to occupy specific ecological niches.     

The Round Goby, Neogobius melanostomus, a Fish Invader on both sides of the Atlantic Ocean

During the past decade, a bottom-dwelling, aggressive, multiple-spawning fish, the round goby (Gobiidae: Neogobius melanostomus), has spread from its native region in the Ponto-Caspian throughout Europe and to the Laurentian Great Lakes in North America. An international workshop, held at the Hel Marine Station, Poland, was organized to summarize population features of the round goby. Common fish predators of round gobies in the Great Lakes and in native regions are obligate and facultative benthic fishes and occasionally, pelagic fishes. In contrast, the main predator of the round goby in the Gulf of Gdansk is the Great Cormorant (Phalacrocorax carbo). In the Great Lakes, round gobies have lead to the decline of mottled sculpin (Cottus bairdi) and logperch (Percina caprodes) and reduced the hatching success of native fishes by feeding on their eggs. In the Gulf of Gdansk, round gobies have increased in abundance, while three-spined sticklebacks (Gasterosteus aculeatus) have declined. Round gobies have a broad diet throughout their range; larger specimens are molluscivores. There are fewer species of parasites and lower infection rates of round gobies in recently colonized areas than in native areas. Overall, newly colonized round gobies in brackish waters and lakes are smaller, mature earlier, have a male biased operational sex ratio and are more short-lived compared with round gobies from marine (native) habitats.     

Biological features of the common fish species in Olyutorsky-Navarin region and the adjacent waters of the Bering Sea: 4. family sculpins (Cottidae)

Based on the materials of investigations conducted for 20 years (1995?2015), the features of biology of the common fish species of the family Cottidae from the northwestern Bering Sea are studied. These species are found during summer and fall in the waters of the Olyutorsky-Navarin region. The size–age parameters of the fishes collected with different fishing gears, as well as the features of their body length and body weight dynamics, spawning time, and spawning conditions, are described. The largest exemplars of shorthorn sculpin Myoxocephalus verrucosus and staghorn sculpins, armorhead sculpin Gymnocanthus galeatus and G. detrisus, are recorded in the catches of snurrevads, while the fishes caught in trawls are characterized by smaller size. Interannual variability of the size composition of the fish is related to the abundance of certain generations or to the fishery directed to different associations of sculpins. In the coastal waters, comparatively low average body size is usual for the majority of common sculpin species (with the exception of lords, yellow Irish lord H. jordani and Gilbert’s Irish lord H. gilberti) because of the dominance of juveniles.     

Some Consequences of Size Variability in Juvenile Prickly Sculpin, Cottus asper

Variation in size among fishes can have important ecological consequences. The origin and persistence of variation in size among a cohort of juvenile prickly sculpin, Cottus asper, was explored experimentally by manipulating the size variability in juvenile fish and the presence of conspecific adult fishes in a factorial design. I found that adult fish significantly suppressed the growth and survivorship of juveniles, while the variance treatment alone had no effect on growth or survivorship. The presence of adults was also associated with a decrease in size variability in the high variance treatment. An analysis of juvenile growth patterns revealed no evidence for size dependent growth or temporal correlations in growth (`growth autocorrelation'), and are consistent with a lack of amplification of size variance through time. Juvenile C. asper appear to have been feeding on a relatively homogeneous resource and utilizing those resources similarly. Thus, patterns of individual growth and the presence of adult conspecifics may both serve to dampen size differences in this coastal fish species.     

Spatial variation in density of stream benthic fishes in northern Hokkaido, Japan: does riparian vegetation affect fish density via food availability?

The densities of two benthic fishes, the Siberian stone loach (Noemacheilus barbatulus) and the wrinklehead sculpin (Cottus nozawae), and the biomass of their food resources (i.e., periphyton and benthic invertebrates) were compared between forest and grassland streams in northern Hokkaido, Japan, to examine whether riparian deforestation had positive effects on the benthic fishes via enhancement of food availability. The comparisons indicated that riparian vegetation had little influence on periphyton, invertebrates, or fishes. Regression analysis indicated that spatial variations in loach and sculpin densities were explained more by substrate heterogeneity, competitor abundance, or both, rather than by food abundance. However, when the two species were combined as benthic insectivores, a strong correlation was found between total benthic fish density and invertebrate biomass. Our results suggest that, although total benthic fish abundance was food limited, riparian vegetation had no positive effects via food availability on the benthic fishes in our streams.     

Species composition,distribution, and specific features of feeding of Fish Larvae,and fry in the Sea of Okhotsk from October to December 2007

Ichthyoplankton of the Sea of Okhotsk from October to December 2007 comprised larvae and fry of eight fish species belonging to five families. The larvae of lord Hemilepidotus gilberti, white-spotted greenling Hexagrammos stelleri, and Atka mackerel Pleurogrammus monopterygius were the most widespread and numerous in the study period. Fish larvae from October to December 2007 were seined over the vast water area of the Sea of Okhotsk, maximum catches were made in waters of western Kamchatka. The food spectrum of larvae of five fish species (H. gilberti, Hexagrammos octogrammus, H. stelleri, P. monopterygius, and Bathymaster signatus) included approximately 20 plankters. Irrespective of species belonging, copepods Pseudocalanus minutus and Oithona similis, eggs and nauplii of copepods, as well as juveniles of pteropods were common food items for all fish. Larvae of all considered fish species in the Sea of Okhotsk fed mainly during the light hours of the day.     

The first demersal trawl survey of benthic fish and invertebrates in the Beaufort Sea since the late 1970s

This study represents the first demersal trawl survey of marine fishes and invertebrates in offshore waters of the Beaufort Sea since 1977. Species composition, distribution, and abundance of demersal fish and benthic invertebrates were assessed with standard methods and demersal trawl gear by the Alaska Fisheries Science Center. Fishes made up 6% of the total catch weight, and invertebrates made up the remaining 94% of the catch weight. A total of 32 species of fish were identified, two taxa were identified to genus and one to family, and 174 taxa of invertebrates were identified. The most abundant demersal fishes were polar cod (Boreogadus saida), eelpouts (Lycodes spp.), Bering flounder (Hippoglossoides robustus), and walleye pollock (Theragra chalcogramma). The most abundant invertebrates were notched brittle stars (Ophiura sarsi), snow crab (Chionoecetes opilio), mussels (Musculus spp.), and the mudstar (Ctenodiscus crispatus). We documented or confirmed extension to the known ranges of four species of fishes: walleye pollock, Pacific cod (Gadus macrocephalus), festive snailfish (Liparis marmoratus), and eyeshade sculpin (Nautichthys pribilovius). We also documented the presence of commercial-sized snow crab (Chionoecetes opilio), which has not previously been recorded in the North American Arctic.     

Dependence of the structure of the capsule surrounding the acanthocephalan Corynosoma strumosum on the species of its natural paratenic host

The fine and ultrafine structure of the capsules surrounding the acanthocephalan Corynosoma strumosum in natural paratenic hosts of three species—the whitespotted greenling Hexagrammos stelleri, Steller’s sculpin Myoxocephalus stelleri, and the saffron cod Eleginus gracilis—was studied. The results of this study, together with earlier data, support the hypothesis that the structure of the capsule depends on the paratenic host species. Three types of capsules differing in the ratio of fibroblasts and inflammatory cells have been identified: fibroblastic (in Japanese smelt, rainbow smelt, and saffron cod), intermediate (in whitespotted greenling), and leukocytic (in Steller’s sculpin and the yellowfin sole). It was assumed that the structure of the capsule is determined by the degree of mutual adaptation of organisms in a given host-parasite system.     

Length‐length and length‐weight relationships for four fish species from Naolihe National Nature Reserve,Heilongjiang, China

In this study the length‐length and length‐weight relationships for four fish species from Naolihe National Nature Reserve in China belonging to three families and four genera were analyzed. They are Perccottus glenii Dybowski, 1877; Rhodeus sericeus Pallas, 1776; Cobitis lutheri Rendahl, 1935; and Misgurnus mohoity Dybowski, 1869. Fish samples were collected in May 2017 from Naolihe National Nature Reserve by fish catching cage (31*41 cm caliber, 16 m length, 3–5 mm mesh diameter), and identified as to species in the laboratory according to S. Q. Zhu (Synopsis of freshwater fishes of China, Jiangsu Science and Technology Publishing House, Nanjing, China, 1995).     

Specific features of distribution and size indices of four poorly studied species of sculpins (Cottidae) in the Okhotsk Sea Waters off Kamchatka

Evidence on occurrence in catches and characteristic of the spatial-bathymetric distribution and size indices of four species of Cottidae—frog sculpin Myoxocephalus stelleri, brightbelly sculpin Microcottus sellaris, antlered sculpin Enophrys diceraus, and furseal sculpin Stelgistrum stejnegeri—in summer-autumn months in the Okhotsk Sea waters off Kamchatka (site from 51°15′ to 57°20′ N, depths of 11–100 m) are provided. The first three species occur mainly in the northern part of the shelf above 54° N at depths smaller than 30–40 m within a comparatively well warmed surface water mass of seasonal modification at near-bottom temperature values above 6°C at various solid grounds. Maximum catches of S. stejnegeri were recorded only at a site of the western Kamchatka shelf from 54°00′ to 54°20′ N on pebbly-stony ground in a narrow bathy-metric range of 41–60 m on the boundary between the well warmed surface water mass of autumn modification and the cold intermediate water mass at a water temperature below 2°C. Evidence on the size-weight indices of the studied species of Cottidae in trawl catches in the Okhotsk Sea waters off Kamchatka in the study period is provided.     

Growth and age of staghorn sculpins of the genus <Emphasis Type="Italic">Gymnocanthus</Emphasis> (Cottidae) in Peter the Great Bay and adjacent waters of Primorye (Sea of Japan)

Age and growth have been studied in four species of staghorn sculpins of the genus Gymnocanthus inhabiting Primorye (the Russian sector of the Sea of Japan). Large black edged and purplegray sculpins, G. herzensteini and G. detrisus, inhabited deeper waters compared with threaded sculpin G. pistilliger and (especially) whip sculpin G. intermedius. The size differences between different sculpin species could already be revealed in the diameter of mature oocytes and the length of hatching larvae and fries passing to the benthic phase of development. The maximum size in these species correlated with their maximum age. G. herzensteini, G. detrisus, G. pistilliger, and G. intermedius could attain the age of no less than 16+, 15+, 9+, and 7+, respectively. The gains in fish of the same age were also greater in species attaining greater size values. In all the species, females lived longer than males and were larger than males of the same age. Throughout the life cycle, the growth rate gradually came down; the decrease was especially pronounced during the period of sexual maturation. In the southern part of the geographic range, the specimens of purplegray sculpin attained smaller size and showed lower growth rate compared with the fish from the northern part of the range. The threaded sculpin demonstrated the inverse relationships. In general, females were dominating in samples of staghorn sculpins; however in small and medium size groups, the proportion of males was greater, which was due to their smaller, compared with females, absolute gains. In elder groups, the proportion of males gradually went down, as they were dying earlier than females.     

Paracapillaria epinepheli n. sp. (Nematoda: Capillariidae) from the red grouper Epinephelus morio (Pisces) from Mexico

A new nematode species, Paracapillaria epinepheli, is described from the stomach of the marine fish Epinephelus morio (Valenciennes), the red grouper, (Serranidae, Perciformes) from coastal waters of the Gulf of Mexico in Yucatan, southeastern Mexico. It is characterised mainly by its small body (body length of male and female 2.73–3.22 mm and 5.94–6.35 mm, respectively), number (31–36) and structure of the stichocytes, length of the spicule (0.180–0.195 mm), structure of the male caudal bursa (considerably reduced), structure and size of the eggs (size 0.057–0.063 × 0.027–0.030 mm), and by their site within the host. It is the second Paracapillaria species known to occur in the marine and estuarine fishes of the Gulf of Mexico.     

Comparative ecology of prickly sculpin,Cottus asper,and coastrange sculpin,C. aleuticus,in the Eel River,California

Synopsis We documented species' distributions, size structure of populations, abundance in mainstem and tributary streams, habitat use, and diets of prickly sculpin, Cottus asper, and coastrange sculpin, C. aleuticus, in the Eel River drainage of California, to determine the processes allowing coexistence of these very similar fishes. We observed prickly sculpins at 43 sites and coastrange sculpins at 34. The species co-occurred at 26 sites. Young-of-year coastrange sculpins were only observed within 42 km of the ocean, but young-of-year prickly sculpins were present throughout the species range. Mean, maximum, and minimum lengths of coastrange sculpins were positively correlated with distance from the ocean but no significant relationships were found for prickly sculpins. Absolute abundance of both species was highest in mainstem habitat (prickly sculpins = 0.6 sculpins m^–2 and coastrange sculpins = 0.4 sculpins m^–2) . Tributary densities of both species tended to be less than 0.1 sculpins m^–2. The species inhabited very similar habitats and had very similar diets. Coastrange sculpin populations in upstream areas were maintained by immigration from downstream areas in contrast with prickly sculpin populations that produced young-of-year fish throughout their range. Densities were probably not high enough for interspecific interactions to be important. The factors limiting the upstream distribution of the species may include high water temperatures, stability of the stream bed, and behavior of the fish. In the past, the range of sculpins within the Eel River drainage probably fluctuated with changing physical conditions. Recent introductions of exotic species that compete with and prey upon sculpins, and ongoing human activities in the drainage could result in major reductions in the distribution and abundance of one or both species.     

Comparisons among survey methodologies to test for abundance and size of a highly targeted fish species

Three sampling methods for estimating abundance and size of blue cod Parapercis colias were compared inside and outside Kapiti Marine Reserve, New Zealand (40° 49′ 31·77^′′ S; 174° 55′ 02·87^′′ E). Two baited methods, baited underwater video (BUV) and experimental angling (EA), were more efficient and had lower levels of estimate variation than diver‐based underwater visual census (UVC). The BUV and EA recorded more fish and of greater size ranges than UVC, and also had fewer zero count replicates. The BUV and EA methodologies revealed highly significant differences in abundance and size of fish between sites (reserve v. non‐reserve), whereas UVC revealed no such differences. These results indicate that BUV is likely to be the most accurate, cost‐effective and easy to use methodology for the surveying of carnivorous temperate reef fishes for future monitoring. It is noted, however, that new data acquired using the BUV methodology may need to be compared over a calibration period to data acquired using the UVC methodology to ensure that historical data sets derived from UVC still have validity and application for future monitoring activity.     

Acoustic telemetry survey of the dusky grouper (Epinephelus marginatus) in the Marine Reserve of Cerbère-Banyuls: informations on the territoriality of this emblematic species

The Marine Reserve of Cerbère-Banyuls represents a refuge for dusky grouper populations (Epinephelus marginatus). Density survey and observation of the reproductive behavior of this species have been conducted there for the last 30 years. However, information on the behavior or habitat utilization for this species during winter time is limited. We conducted acoustic telemetry surveys from September 2005 to June 2006 in the Marine Reserve of Cerbère-Banyuls for a dusky grouper population. Six groupers were tagged and followed within the integral reserve and in the adjacent partial reserve. The results from the tracking of these individuals indicated that the largest dusky groupers are sedentary fishes with a high degree of site fidelity and a high sensitivity to variations of environmental conditions such as storms. This together with the life history characteristics of this species encourages the conservation and the protection of essential habitats of this species. Acoustic tracking coupled to the use of a fixed Kernel can be proposed to follow fish populations. To cite this article: J. Pastor et al., C. R. Biologies 332 (2009).     

Brown trout and food web interactions in a Minnesota stream

1. We examined indirect, community‐level interactions in a stream that contained non‐native brown trout (Salmo trutta Linnaeus), native brook trout (Salvelinus fontinalis Mitchill) and native slimy sculpin (Cottus cognatus Richardson). Our objectives were to examine benthic invertebrate composition and prey selection of fishes (measured by total invertebrate dry mass, dry mass of individual invertebrate taxa and relative proportion of invertebrate taxa in the benthos and diet) among treatments (no fish, juvenile brook trout alone, juvenile brown trout alone, sculpin with brook trout and sculpin with brown trout). 2. We assigned treatments to 1 m² enclosures/exclosures placed in riffles in Valley Creek, Minnesota, and conducted six experimental trials. We used three designs of fish densities (addition of trout to a constant number of sculpin with unequal numbers of trout and sculpin; addition of trout to a constant number of sculpin with equal numbers of trout and sculpin; and replacement of half the sculpin with an equal number of trout) to investigate the relative strength of interspecific versus intraspecific interactions. 3. Presence of fish (all three species, alone or in combined‐species treatments) was not associated with changes in total dry mass of benthic invertebrates or shifts in relative abundance of benthic invertebrate taxa, regardless of fish density design. 4. Brook trout and sculpin diets did not change when each species was alone compared with treatments of both species together. Likewise, we did not find evidence for shifts in brown trout or sculpin diets when each species was alone or together. 5. We suggest that native brook trout and non‐native brown trout fill similar niches in Valley Creek. We did not find evidence that either species had an effect on stream communities, potentially due to high invertebrate productivity in Valley Creek.     

长江口盐沼植被生境内斑尾刺虾虎鱼食性特征

根据2015年5月至2016年4月在长江口东滩盐沼湿地水域采集的斑尾刺虾虎鱼样本数据,分析了该生境斑尾刺虾虎鱼的生物学和食性特征。结果表明:共采集到斑尾刺虾虎鱼186尾,其中6—8月采集的数量较高,而其他月份较低。约96%个体为幼体(平均体长109 mm),平均摄食等级为1.5。斑尾刺虾虎鱼主要摄食虾类(IRI(%)=69.05)、鱼类(IRI(%)=17.31)、蟹类(IRI(%)=11.51)和双壳类(IRI(%)=0.95)等11大类41小类饵料生物;虾类作为最重要的饵料类别,其生物量、数量和出现频次百分比均排列第一,以安氏白虾(Exopalaemon annandalei)、日本沼虾Macrobrachium nipponense)、长额刺糠虾(Acanthomysis longirostris)等虾类为主要饵料。鱼类饵料中,以大鳍弹涂鱼(Periophthalmus magnuspinnatus)、大弹涂鱼(Boleophthalmus valenciennes)等虾虎鱼科鱼类为主要饵料。各月平均饱满指数P(%)波动较大,6—11月呈逐渐增加趋势。随着体长的增加,饵料组成中鱼类的比例呈逐渐增高趋势,成体个体的饵料中鱼类的生物量比例达65%以上,虾类的比例则下降明显。6—8月斑尾刺虾虎鱼白天样本中鱼类饵料的重量百分比显著高于夜晚(P0.01),约是夜晚的8倍;但虾类则是夜晚显著高于白天(P0.01),约是白天的2倍,而蟹类饵料的昼夜差异不显著。从等级聚类(即组平均法)的分类方法可知,斑尾刺虾虎鱼各体长组食物组成在10%相似性水平上可分为3类,即41—60、61—180 mm和181—200 mm。从营养生态位宽度来看,41—60 mm体长组生态位宽度值为0.86,而61—120 mm体长组随着体长的增大而增大,但121—160 mm体长组生态位有所降低。盐沼生境丰富的饵料环境为斑尾刺虾虎鱼提供了良好的摄食场所,同时盐沼植被茂密的植株也可为幼体提供躲避捕食者的最佳庇护所,初步证明盐沼对于斑尾刺虾虎鱼具有重要的生境价值。