Distribution and some features of biology of sea raven <Emphasis Type="Italic">Hemitripterus villosus</Emphasis> (Hemitripteridae) in the northwestern part of the Sea of Japan

On the basis of long-term (1981–2008) observations, it was shown that, in the northwestern part of the Sea of Japan, sea raven Hemitripterus villosus is a common species with low, but stable numbers and it is a part of elittoral ichthyocenoses. During the year it performs wintering, feeding, and spawning migrations within the shelf and the upper part of the continental slope occurring from almost the water’s edge to a depth of 550 m. Highest density of sea raven is observed in Peter the Great Bay and the lowest is observed off the coasts of northern Primorye. Maximum length of H. villosus in the northwestern part of the Sea of Japan reaches 57 cm, and the modal group of fish consists of fish with a length of 25–45 cm (75%). In Peter the Great Bay, in the summer period, individuals with a length of 11–50 cm feed mainly on mass fish species; the value of daily ration of H. villosus varies from 1.6 to 3.2% of body weight, averaging 2.5%. According to an expert estimate, the biomass of sea raven in the northwestern part of the Sea of Japan reaches 2000 t.     

New data on biology of the pearlfish <Emphasis Type="Italic">Maurolicus imperatorius</Emphasis> (Sternopthychidae) from the Emperor Seamount Chain

The pearlfish Maurolicus imperatorius occurs above seamounts of the Emperor Seamount Chain between 30°–40° N and 168°–176° E. It forms dense aggregations at the daytime in the upper mesopelagial above the ground and disperses in the dark period of the day in the surficial layer. Judged by maturation dynamics of gonads, the spawning of this species occurs from January until April with the maximum in March. Catches of this species are characterized by expressed seasonal dynamics of size composition. Juveniles appear in catches in the end of spring-the beginning of summer. The maximum recorded SL is 68 mm. Among large fish, females dominate. The part of females is maximum in winter and minimum in spring. The age of fish with AC 46–63 mm is 265–420 days. The growth rate is abruptly retarded at the fourth month of life when the length 40–45 mm is attained. Life duration of most fish does not exceed 1.5 years, though some specimens may attain the age of two years. It is supposed that the presence of another species—M. japonicus—on the Emperor Seamount Chain may result from passive transfer in the Kuroshio waters.     

Occurrence of skate <Emphasis Type="Italic">Raja pulchra</Emphasis> (Rajidae,Rajiformes) in Russian waters of the Sea of Japan

According to data of long-term observations in Russian waters of the Sea of Japan, it was shown that skate Raja pulchra occurs only off the coasts of western Sakhalin. In all probability, it is a constant inhabitant of these waters during the course of the year; like the overwhelming majority of bottom and near-bottom fish, it performs seasonal bathymetric migrations in autumn, for wintering to the insular slope to a depth of 695 m, and in spring to shallow waters. Maximum length of R. pulchra recorded in catches is 106 cm. The main food items of R. pulchra are decapods and fish. The stock of R. pulchra off the coasts of western Sakhalin is assessed as 520 t.     

Distribution and some traits of biology of <Emphasis Type="Italic">Lycodes tanakae</Emphasis> (Perciformes: Zoarcidae) in Primor’e waters (Sea of Japan)

With consideration of investigations made in 2004–2010, the spatial distribution of Lycodes tanakae, as well as some traits of its biology in Primor’e waters, is described. This species occurs all over the investigated region—from 42° to 49°N as explained by hydrological properties of bottom waters and by the bottom relief of this water area. In Promor’e waters, Lycodes tanakae occurs at depths of 87–1034 m. However, the majority of specimens (90%) prefers depths of 200–700 m. Thus, it can be attributed to the mesobathial ecological fish group. In spring and summer, juveniles of L. tanakae live at similar depths (200–350 m) where this species seems to spawn. In catches, L. tanakae is represented by specimens 11–90 cm in length, 0.1–4.9 kg in weight, and age from 1 to 10 years. The bulk of catches consists of specimens 40–70 cm long (62%), up to 2.2 kg in weight (90%), and of the age 4–7 years (72%). Sexual dimorphism in linear dimensions is not determined in L. tanakae. In summer, the ration of L. tanakae in Primor’e waters consists predominantly of cephalopods (on average, 59.4% of food weight). A noticeable part belongs to decapods (19.8%) and fish juveniles (16.6%). The smallest analyzed specimens consume small decapods and polychaetes. At the body length over 40 cm, L. tanakae pass over to predation. The value of the daily ration of Lycodes tanakae is, on average, 1.5% of the body weight.     

Feeding of the leech <Emphasis Type="Italic">Glossiphonia weberi</Emphasis> on the introduced snail <Emphasis Type="Italic">Pomacea bridgesii</Emphasis> in India

The predation potential of the indigenous leech Glossiphonia weberi on the snail Pomacea bridgesii, introduced in India, was evaluated in the laboratory. Snails used belonged to the size-classes ≤‰3.0, 3.1–5.0, 5.1–7.0 and 7.1–9.0 mm in shell height, using them both separately and together (mixed) in combinations. In each experiment lasting 24 h a single leech belonging to the size-classes 2.0–3.9, 4.0–5.9, 6.0–7.9, 8.0–9.9 and 10.0–11.9 mm in length was used. Except the 4.0–5.9 mm size-class, leeches were able to capture and kill P. bridgesii irrespective of latter’s size; the predation, however, was confined to snails ≤3.0 mm. The rate of predation varied with the size of the predator and the prey, and a leech was able to kill a maximum of three snails per day. In India, in nature G. weberi feeds mostly on the pulmonate snail, Lymnaea (Radix) luteola. Experimental studies, however, revealed that G. weberi prefers the snails P. bridgesii and L. (R) luteola at the same rate from amongst the many other either less or not-preferred native operculate and non-operculate snails.     

The reproductive cycle,size at maturity and fecundity of garfish (<Emphasis Type="Italic">Belone belone</Emphasis>, L. 1761) in the eastern Adriatic Sea

A recent study concerning the reproductive biology of the garfish (Belone belone, L. 1761) has been carried out in the eastern part of the Adriatic Sea along the Croatian coastline. Specimens of the fish (N = 3,393) were collected over a 6-year period (2003–2008). Their length varied between 20.8 and 75.4 cm (mean ± SD = 38.3 ± 7.94). Female garfish were dominant in larger length groups being most apparent during the resting phase of sexual cycle and in the peak of the spawning period, occurring in April and May. The sexual ratio of all specimens was m/f = 0.98. Males were prevalent in March—at the beginning of the highest spawning activities. Fifty percentage of the garfish population sexually matured at 28.5 cm of total length. Males and females reached their sexual maturity at 28.0 and 31.5 cm of total length, respectively. Spawning began in January peaking during March to May. According to their maturity stages, gonad weight and the gonadosomatic index, males began to spawn one month earlier (April) than females (May). The mean batch fecundity of garfish was 1,242.46 ± 843.64 of matured oocytes per ovary. Matured oocyte diameters ranged from 1.223 to 4.283 mm with the mean value of 2.269 ± 0.332 mm.     

<Emphasis Type="Italic">Drepanocladus longifolius</Emphasis> (Amblystegiaceae), an addition to the moss flora of King George Island,South Shetland Islands,with a review of Antarctic benthic mosses

Drepanocladus longifolius (Mitt.) Paris is recorded for the first time from King George Island, South Shetland Islands, in the maritime Antarctic. It was collected in West Lake during the 23rd Chinese National Antarctic Research Expedition in 2006–2007. The moss was found at a depth of 5–6 m attached to the bed of the lake. The stems of the moss are about 1–1.5 m in length. The moss exhibits seasonal growth patterns, with shorter branch internodes, more widely spaced leaves and more branches in summer than in winter. Most of the branches are initiated in summer. The annual shoot extension is about 3–6 cm, which implies that the plants must be at least 15 years of age. The distribution of aquatic moss species and records in Antarctica is outlined and discussed and the nomenclature of previous reports clarified.     

The distribution and some biological features of Stichaeus grigorjewi (Stichaeidae) in the waters of northern Primorye (The Sea of Japan)

Stichaeus grigorjewi is a common species, but in the waters of northern Primorye it is comparatively rare. It occurs at depths down to 465 m for the greater part of the year, except for the spawning period, staying in deep-water masses with relatively stable temperature conditions. The widest bathymetric distribution of S. grigorjewi is observed from spring-early summer. After the completition of spawning, it shifts to depths larger than 100 m and winters in the upper section of the continental slope. During each season maximum concentrations of S. grigorjewi along the coasts of Primorye are observed in water from Povorotnyi Cape to the Olga Gulf. Males and females of this species have close rates of growth and reach an age of not less than 12+ years. Most individuals of S. grigorjewi in catches had a length of 37 to 44 cm and fed mainly on fish.     

On reproduction of longfin thornyhead <Emphasis Type="Italic">Sebastolobus macrochir</Emphasis> (Scorpaeniformes: Sebastidae) in waters off the eastern coast of the Kurils

According to data obtained off the eastern coast of the Northern Kurils in October–December 1998, the body length of spawning females of the longfin thornyhead Sebastolobus macrochir is 26–41 cm (on average, 31.5 ± 0.27). Mass spawning is recorded in females 28 cm in length and longer. The individual absolute fecundity of females is 69355-411710 (on average, 189086 ± 13662) eggs. The reproductive potential of females of the longfin thornyhead is estimated as 189 million eggs. It is supposed that all females participate in spawning.     

Geographic range and cold hardiness of the earthworm <Emphasis Type="Italic">Drawida ghilarovi</Emphasis> (Oligochaeta,Moniligastridae)

The earthworm Drawida ghilarovi Gates 1969 is a typical representative of the Amur fauna and the only species of the tropic family Moniligastridae on the territory of Russia. The northern boundary of its range passes from the Khingan (Hinggan) River on the west, along the mountain framing of the Amur plains, to Evoron Lake (or, probably, to the Amgun River valley) on the east. Drawida ghilarovi is widespread in the Sikhote Alin, but the northern boundary of its distribution in the northern part of this mountain range has not been delimited; the same applies to the left bank of the Amur downstream of Komsomolsk-on-Amur and its lower reaches. These earthworms lay cocoons in summer in the surface soil horizon (0–20 cm) and overwinter also at a depth of only 15–20 cm, although D. ghilarovi is classified as an anecic (deep burrower) species (Vsevolodova-Perel, 1997). The median lethal temperature (LT_50%) is about −15°C for cocoons and −12°C for worms; the minimum tolerable temperature, about −20 and −16°C, respectively. The mechanism of protection against freezing in cocoons involves a decrease in water content from an average of 71.1 ± 0.8% to a minimum of 39.8%; this decrease in worms is less significant: from 85.5 ± 0.8% (feeding worms) to 75.3 ± 0.7% (wintering worms). Since the development of juveniles in cocoons is completed by autumn, the critical factor is the minimum temperature to which the worms are exposed. In woodless areas near Khabarovsk, the average soil temperature at a depth of 40 cm during the coldest month is only 2–3°C higher than LT_50% (the difference is greater in forest habitats), and the minimal temperature should be still lower. Under current climatic conditions, D. ghilarovi could have inhabited the area extending over the Zeya River basin and, in the north, to the sources of left-bank tributaries of the middle and lower reaches of the Amur (not everywhere, but in the warmest habitats). The present-day boundaries of the D. ghilarovi appear to reflect past changes in climatic and soil conditions.     

Age and growth of spiny dogfish <Emphasis Type="Italic">Squalus acanthias</Emphasis> (Squalidae,Chondrichthyes) in pacific waters off the Kuril Islands

On the basis of materials collected from catches of drift salmon nets in Pacific waters off the Kuril Islands from 2005 to 2006, the age and rate of growth of spiny dogfish Squalus acanthias are considered. Individuals with a length of 67–123 cm and weight of 1140–5970 g aged 10–26 years were represented in catches. In almost all age classes, the length of males was greater and the weight smaller than in females. The lifespan of females is slightly higher as compared to males-26 and 25 years, respectively. The values of K coefficient of the Bertallanffi equation of growth in males and females comprised 0.10 and 0.05 and the calculated values of the asymptotic body length comprised 116.3 cm and 147.2 cm. A relationship was found between the age of spiny dogfish and the spine size: its length (r _s = 0.693), base width (r _s = 0.815), and base length (r _s = 0.823).     

Peculiarities of the population of <Emphasis Type="Italic">Bythotrephes brevimanus</Emphasis> lilljeborg, 1901, in lake pleshcheevo (the Upper Volga Basin)

The morphological and biological features of Bythotrephes—a relatively rare crustacean in Lake Pleshcheevo—have been identified on the basis of vast material (several hundreds of individuals) collected in August 2010. The individuals were distinguished by a minimal body size, short caudal appendix, absence of a loop, and very small caudal claws and were identified as Bythotrephes brevimanus Lilljeborg, 1901. The morphology of the crustacean corresponds to the high water mineralization in the lake and the relative stability of the environment. Some peculiarities of molt and growth of the crustacean were distinguished. A chitinous integument of the caudal appendix formed during embryogenesis has a different structure than chitin formed during further molts. In August, the population of B. brevimanus in different areas of the lake was stable and consisted only of juveniles and parthenogenetic females (80%) (4–6 eggs). The largest number of crustaceans (150 ind./m³) was recorded in the periphery of the depression above depths of 6–7 m; 80 ind./m³ were recorded above depths of 11–12 m; and, above the depression, there were less than 30 ind./m³. The small density of crustaceans in the pelagial depends on the intensive grazing of this food object selected by fish in especially transparent water (color 15–20 and transparency 300–600 cm).     

Distribution of <Emphasis Type="Italic">Calanus</Emphasis> populations in a glaciated fjord in the Arctic (Hornsund,Spitsbergen)—the interplay between biological and physical factors

The distribution and diversity of copepods of the genus Calanus were investigated in Hornsund Fjord (on the southwest coast of Spitsbergen) in summer 2001. The Bhattacharya method was used to sort individuals by species based on their prosome length. The established prosome length boundary values for the Calanus copepodid stages coincided with those defined for the Calanus species from Kongsfjorden (on the northwest coast of Spitsbergen). The predominant species in the main and inner fjord basins was Calanus glacialis, whereas Calanus finmarchicus was the prevailing species outside Hornsund. Younger copepodid stages (CI–CIII) of both species concentrated in the surface water layers (0–50∼70 m), while older copepodids (CIV–CVI females) that were ready for wintering stayed in deep layers (50∼70 m to bottom). Calanus hyperboreus was present in low numbers, predominantly as CIV, and in Hornsund deep water layers. The distribution and diversity of Calanus species complied with the notion that the marine fauna in Hornsund is of a more Arctic character than in Kongsfjorden, a fjord 260 km to the north on the west coast of Spitsbergen.     

Effects of body-size and season on digestive organ size and the energy balance of cockles fed with a constant diet of phytoplankton

Seasonal variation in size-dependence of seawater clearance rate, absorption efficiency, oxygen consumption, gill area, length of the crystalline style and dry weight of digestive gland was analyzed in cockles Cerastoderma edule from the Mundaka Estuary, Spain. Experimental determinations were performed monthly (from July 1998 to November 1999) in cockles being fed with Tetraselmis suecica (organic content: 87.84 ± 1.95%) at a concentration of 3 mm³/l for 3 days. Analysis of covariance reveals no seasonal differences in both size-dependence of seawater clearance rate and oxygen consumption, which were found to scale to dry body weight with mass-exponents of 0.56 and 0.62, respectively. No significant correlation was found between absorption efficiency and body weight. Mass-exponents for gill area, dry weight of the digestive gland and length of the crystalline style remained constant among seasons showing values of 0.62, 0.34 and 0.82, respectively. Seasonal trends for every physiological determination were calculated for a standard size (200 mg) cockle: standardized clearance rates and oxygen consumptions followed a similar trend with minimum values in winter (≈0.5 l/h and ≈100 μl O₂/h, respectively) and maximum values during spring–summer (≈1.7 l/h and ≈250 μl O₂/h, respectively), whereas absorption efficiency and food throughput time showed both the opposite pattern with highest values corresponding to winter months (≈50–60% and ≈5–6 h, respectively), and lowest (≈30% and ≈3–4 h, respectively) to summer–autumn. Scope for growth exhibited minimum values in winter followed by a rapid increase along the winter–spring transition, maximum values being attained in spring (May) and summer (July). Exponential decline of seasonal values of absorption efficiency associated to rising ingestion rates of organic matter presented an asymptotic minimum at 0.35. Absorption efficiency was positively related to food throughput time, whereas the latter fell to a minimum of 3.548 h with increasing food intake. So, maintenance of throughput time—and consequently absorption efficiency—along with enhanced filtering activity provided cockles with higher absorption rates improving scopes for growth registers during spring and summer. These dynamics might be explained as the consequence of the seasonal digestive adjustments in cockles, which, in fact, were found to increase the size of the digestive organs during that period.     

Reproductive Strategies of <Emphasis Type="Italic">Trachypithecus pileatus</Emphasis> in Arunachal Pradesh,India

We studied reproductive behavior of free-ranging capped langurs (Trachypithecus pileatus) in the Pakhui Wildlife Sanctuary, Arunachal Pradesh, India. Four species of primates —Trachypithecus pileatus, Macaca mulatta, M. assamensis, and Nycticebus bengalensis— live there. We studied the mating seasons, mating frequency, copulatory attempts, time spent in copulation, and interval between 2 successive copulations, gestation length, and interbirth interval of 4 groups of capped langurs during 2001–2003. We observed 2 mating seasons in a year. The first was larger, comprising 5 months (September–January), and the second was short, April and May. Mating was intensive in the morning session (0600–1000 h); 57% of total mating events occurred then. The average gestation period was 200 d. November was the most favorable month for breeding. In a year, 107 mating events occurred involving 5 adult females. Average time per mounting attempt is 12 s. Duration of mounting was the maximum in November. Interbirth interval was 23 months and 10 d. The birth season was 129 days, December–April; 53% of births occurred in February and March. Average birth rate is 0.386 birth/female/yr.     

Recurrent high-biomass blooms of <Emphasis Type="Italic">Alexandrium taylorii</Emphasis> (Dinophyceae), a HAB species expanding in the Mediterranean

Summer outbreaks of the dinoflagellate Alexandrium taylorii Balech are recurrent events in nearshore waters of Sicily (Italy)—a central region in the Mediterranean Sea—producing dense yellowish–green patches. Beyond the local phenomenon, the problem covers a broader geographic scale, involving also other European localities, mostly in Spain. Biological, environmental, and molecular data are reported here from a semi-closed bay of Sicily (Vulcano Island, Tyrrhenian Sea, 2000–2003), showing in summer the recurrence of high-biomass blooms and events of water discolouration. Without underestimating the setbacks to the tourism industry, the ecological impact of A. taylorii blooms may be important considering the high levels of biomass produced (West Bay, Vulcano: up to a magnitude order of 10⁷ cells l⁻¹, 50–180 μg-Chla l⁻¹, June 2002 and 2003) and coincident conditions of oxygen supersaturation of the waters (130–170%). Trophic trends in the Tyrrhenian site indicate high amounts of nutrients linked to the increased anthropogenic activity in summer, although recently there has been an apparent shift of the marked eutrophic conditions towards a slighter eutrophy. Genetic data on isolates of A. taylorii from the Mediterranean Sea are also discussed. Molecular analyses implied the sequencing of target rDNA regions (5.8S rDNA and ITS regions) of several isolates from different Mediterranean localities, as well as the application of species-specific PCR assays for rapid species identification in preserved field samples. The confirmation of the specific identity provided new insights into the biogeography of this species and further evidence of the occurrence of A. taylorii in a number of Mediterranean localities, both in the western side (the Catalan coast of Spain) and the eastern area (Greece). Analyses of the molecular diversity of geographically distinct isolates of A. taylorii from Italy, Spain, and Greece based on the 5.8S rDNA-ITS region sequences showed a high level of similarity, indicating the existence of an unique Mediterranean population.     

Feeding interactions and diet of carnivorous fishes in the Shelikhov Bay of the Sea of Okhotsk

The food spectra, trophic statuses, and feeding interrelations of three most abundant benthic carnivorous fish species inhabiting the Shelikhov Bay—the Pacific cod Gadus macrocephalus, the great sculpin Myoxocephalus polyacanthocephalus, and the Okhotsk sculpin M. ochotensis—are considered based on materials collected during the complex survey of the RV Professor Kaganovsky of the TINRO-Center, in September 2004. It was found that these species were facultative predators with wide food spectra. The significance of prey objects in the diet of the Okhotsk sculpin was as follows: crustaceans, fish, and mollusks. Great sculpin and Pacific cod preyed mostly on fish, then on crustaceans, and mollusks. Pacific cod ate equal proportions of fish and decapods. All the species had age-related variability of diet. The potential competition of great sculpin and Okhotsk sculpin for food was mitigated by the difference in the depths of their ranges, as well as by morphological (body size) and behavioral peculiarities in the areas where their habitats overlapped, and in microecosystems. The most probable competition was among Pacific cod 30–60 cm long and Okhotsk sculpin 20–50 cm in length, as well as among cod and great sculpins of all sizes.     

Antimicrobial activity of the extracts from fruits of <Emphasis Type="Italic">Rumex</Emphasis> L. species

This study was designed primarily to investigate the antibacterial and antifungal activity of the extracts from fruits of six Rumex L. species: R. acetosa L., R. acetosella L., R. confertus Willd., R. crispus L., R. hydrolapathum Huds. and R. obtusifolius L. The 7 Grampositive and 7 Gram-negative bacteria strains and 5 fungal ones were tested by agar and broth dilution method. Determination of minimal inhibitory concentration (MIC) revealed that the extracts from R. confertus, R. crispus, R. hydrolapathum and R. obtusifolius exerted differential inhibitory effect on the growth of Gram-positive bacteria — staphylococci (MIC=62.5–125 μg/mL) and Gramnegative bacteria — Escherichia coli ATCC 3521, Proteus mirabilis, Pseudomonas aeruginosa (MIC=125→500 μg/mL); MIC values determined by agar dilution method were somewhat higher. The same extracts inhibited also the growth of fungi — Candida spp. or Trichophyton mentagrophytes ATCC 9533 (MIC=250–500 μg/mL), as found by agar dilution method. The total content of polyphenols (11.66–78.36 mg/g), anthracene derivatives (0.26–12.93 mg/g) and tannins (4.00–11.16%) was also determined.     

Identifying patterns in the diet of mackerel icefish (<Emphasis Type="Italic">Champsocephalus gunnari)</Emphasis> at South Georgia using bootstrapped confidence intervals of a dietary index

Ontogenetic, inter-annual and regional variations in diet were investigated for mackerel icefish, Champsocephalus gunnari, in three successive summer seasons around South Georgia. Stomach contents from 2239 C. gunnari (130–560 mm total length) were examined. A bootstrapping technique was used to calculate confidence intervals for an index of relative importance of prey categories (% IRI_DC). Diet varied significantly between years and age classes but there was little regional difference in diet. In general, diet was dominated by krill, Euphausia superba and by the amphipod Themisto gaudichaudii. Smaller (younger) fish tended to prey on a higher proportion of T. gaudichaudii and small euphausiids such as Thysanoessa sp. and took smaller quantities of E. superba. In a season of poor krill availability (summer of 2003–2004) the proportion of krill in the diet, stomach fullness and fish condition (indicated by length–weight relationships) were significantly lower than in the other summer seasons. A large reduction (>80%) in the estimated annual (2005) biomass of the C. gunnari stock directly followed the season of poor krill availability. This decline was largely because of mortality of 2+ and 3+ fish, which were more krill dependent than 1+ fish. Younger fish appear to have survived, leading to an increase in the estimated population biomass in 2006.     

Some issues related to catches of northern Atka mackerel <Emphasis Type="Italic">Pleurogrammus monopterygius</Emphasis> (Scorpaeniformes: Hexagrammidae) in the near-surface water layer of the northern Kuril Islands

Studies performed in Pacific waters of the northern Kuril Islands from May to August 2003–2007 demonstrated that not only juveniles of Pleurogrammus monopterygius but also its adult specimens are found in the near-surface layer. Some adult fish migrate to the near-surface layer for feeding, while occurrence in this layer for other specimens is related to the change of spawning grounds. Among specimens with a length of 36–48 cm, females comprise 86.2%; among specimens with a length of 22–28 cm, females comprise 56%. Migrations in the near-surface layer have no mass pattern.