The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Erlend Moksness - One of the best experts on this subject based on the ideXlab platform.
-
Effects of water temperature on protein synthesis and protein growth in juvenile Atlantic wolffish (Anarhichas Lupus)
Canadian Journal of Fisheries and Aquatic Sciences, 1999Co-Authors: Ian D. Mccarthy, Dimitri A. Pavlov, Erlend Moksness, Dominic F. HoulihanAbstract:The effects of water temperature (5, 8, 11, and 14°C) on the fractional rate (percent per day) of protein consumption (kr) and on white muscle and whole-body fractional rates of protein synthesis (...
-
The effects of temperature on growth rate and growth efficiency of juvenile common wolffish
Aquaculture International, 1998Co-Authors: Ian Mccarthy, Erlend Moksness, Dimitri A. PavlovAbstract:The effects of temperature on the survival, growth rate and growth efficiency of larval and juvenile common wolffish, Anarhichas Lupus L. were studied at 0–31 days and 9–12 months post-hatching, respectively. The influence of temperature regime during egg incubation on subsequent survival and growth was also examined. The fish were reared at constant water temperatures of 5, 8, 11 and 14°C, and all groups were fed dry pellets. At age 1 month, maximum growth rates were observed at 11 and 14°C. Growth rates and survival of early juveniles were dependent upon incubation history, high growth being obtained only if rearing temperature exceeded the temperature of egg incubation. In juveniles at age 9–12 months, the relationships between temperature and growth, and temperature and growth efficiency were parabolic: the optimum water temperatures for growth (Topt.G) and growth efficiency (Topt.GE) were 11°C and 9.7°C respectively. The growth rate and growth efficiency at these water temperatures were 0.9% day–1 and 0.45 g weight gain per g food offered, respectively. © Rapid Science Ltd. 1998
-
Development of the axial skeleton in wolffish, Anarhichas Lupus (Pisces, Anarhichadidae), at different temperatures
Environmental Biology of Fishes, 1997Co-Authors: Dimitri A. Pavlov, Erlend MoksnessAbstract:The ontogeny of the axial skeleton, in particular the caudal skeleton, is described from embryos to adult specimens in common wolffish, Anarhichas Lupus. The eggs were incubated at constant temperatures of 7.0, 11.0 and 13.0 °C. High egg mortality and structural changes in skeletal development (fusion of parts, absence of distal radials and most of dorsal and anal fin rays, abnormal neural arches and dorsal fin rays) were observed at 13 °C. The frequencies of some anomalies were lower at 11 °C than at 13 °C. The main reason of structural changes of the skeleton at high temperature is the breaking of normal correlations between developmental rates of some cartilaginous structures and other tissues and organs of the embryo. These data suggest an epigenetic mechanism of skeletal evolution.
-
Spermatozoon ultrastructure and sperm production in wolffish (Anarhichas Lupus), a species with internal fertilization
Aquatic Living Resources, 1997Co-Authors: Dimitri A. Pavlov, Pål Knudsen, Natal'ya G. Emel'yanova, Erlend MoksnessAbstract:L'ultrastructure du spermatozoide et la production de sperme ont ete observees chez le poisson-loup (Anarhichas Lupus), une espece a fecondation interne, a partir d'un elevage. Le spermatozoide, arrive a maturite, a une tete allongee et un flagelle excentre, et un corps intermedaire comparativement bien developpe. La longueur moyenne de la tete du spermatozoide et du flagelle sont 3,3 et 21,2 μm respectivement. La taille des cellules du sperme est tres variable, due a la presence de spermatides et de spermatozoides degeneres. Chez la plupart des mâles, la production de sperme a ete observee tout au long de l'annee avec un pic d'abondance en decembre et en janvier. La production de sperme diminue a la fin de la saison de reproduction. La difference de volumes de l'ejaculat et du sperme entre mâles gardes sous deux cycles differents d'eclairement (18 h nuit: 6 h jour et inversement) n'etait pas significative. Les caracteristiques du sperme du poisson-loup sont comparees aux donnees bibliographiques d'autres poissons a fecondation interne et externe.
-
Management by life cycle of wolffish, Anarhichas Lupus L., a new species for cold‐water aquaculture: a technical paper
Aquaculture Research, 1996Co-Authors: Erlend Moksness, Dimitri A. PavlovAbstract:Interest in the cultivation of wolffish arose in recent years due to their high-quality meat and fast growth in captivity. In wolffish, an almost juvenile organism, more than 20 mm long, hatches from the egg and can be fed dry pellets just after that. This makes the technology for wolffish breeding much simpler than for other marine fishes, even salmonids. This paper is devoted to common wolffish. Anarhichas Lupus L., as the captive breeding of this species has been studied most completely. Experience with broodstock management, insemination, incubation of eggs, start feeding, and growth of rearing juveniles until maturation is described, based mainly on investigations made in Norway and in the Russian Federation. The conditions for obtaining maximum production in the shortest time are assessed. Prospects for using wolffish in aquaculture are briefly discussed.
Pierre U. Blier - One of the best experts on this subject based on the ideXlab platform.
-
Thermal sensitivity of cardiac mitochondrial metabolism in an ectothermic species from a cold environment, Atlantic wolffish (Anarhichas Lupus)
Journal of Experimental Marine Biology and Ecology, 2010Co-Authors: Hélène Lemieux, Jean-claude Tardif, Jean-denis Dutil, Pierre U. BlierAbstract:To produce energy, mitochondria use oxidative phosphorylation, a multistep process involving several integrated reactions influenced by temperature. In order to identify which step in the process was most sensitive to temperature in a cold-temperate ectothermic species, we measured the thermal sensitivity of mitochondrial oxidative phosphorylation, as well as the thermal sensitivity of each individual step in this process, in mitochondria isolated from the heart of Atlantic wolffish (Anarhichas Lupus). The thermal sensitivity of oxidative phosphorylation (coupled, ADP-stimulated), measured in the presence of pyruvate and malate as substrates, and those of Complexes II and IV activities were the same over the whole range of assay temperatures (5 to 35 °C). In contrast, the thermal sensitivity of Complexes I and III, ATPase, pyruvate dehydrogenase and citrate synthase could not be correlated with the thermal sensitivity of oxidative phosphorylation. The first step in the process of oxidative phosphorylation to be negatively affected by increased temperature was shown to be Complex III, followed by the Complex I. This occurred at temperatures above the tolerance limit and well above the range of temperatures occupied by the species. Our results identify specific steps within the electron transport system as potential control point limiting the capacity of Atlantic wolffish cardiac mitochondrial metabolism in response to changes in temperature.
-
Characterization of the early-stages of the wolffish hybrid Anarhichas minor × Anarhichas Lupus : conservation and aquaculture applications
Aquatic Living Resources, 2009Co-Authors: Catherine M. Gaudreau, Nathalie R. Le François, Helge Tveiten, Delphine Ditlecadet, Pierre U. BlierAbstract:This is the first report of early-life developmental characteristics (coloration pattern, growth and survival) and genetic identification of the wolffish interspecific hybrid between Anarhichas minor and A. Lupus, both endangered species in Canadian coastal water and of interest for cold-water aquaculture diversification. A first growth trial at 8 ◦ C featuring pure strains A. minor and the hybrid A. minor × A. Lupus in triplicates was conducted in 2006 during the period from 0 to 140 days post-hatch. A second growth trial was runned in 2007 featuring A. minor, A. Lupus and the reciprocal hybrids A. minor × A. Lupus and A. Lupus × A. minor. Egg development indicators and early-hatching characteristics are reported.
-
characterization of the early stages of the wolffish hybrid Anarhichas minor Anarhichas Lupus conservation and aquaculture applications
Aquatic Living Resources, 2009Co-Authors: Catherine M. Gaudreau, Helge Tveiten, Delphine Ditlecadet, Nathalie Le R Francois, Pierre U. BlierAbstract:This is the first report of early-life developmental characteristics (coloration pattern, growth and survival) and genetic identification of the wolffish interspecific hybrid between Anarhichas minor and A. Lupus, both endangered species in Canadian coastal water and of interest for cold-water aquaculture diversification. A first growth trial at 8 ◦ C featuring pure strains A. minor and the hybrid A. minor × A. Lupus in triplicates was conducted in 2006 during the period from 0 to 140 days post-hatch. A second growth trial was runned in 2007 featuring A. minor, A. Lupus and the reciprocal hybrids A. minor × A. Lupus and A. Lupus × A. minor. Egg development indicators and early-hatching characteristics are reported.
-
Trypsin-Like Enzyme from Atlantic Wolffish (Anarhichas Lupus) Viscera: Purification and Characterization
Journal of Aquatic Food Product Technology, 2008Co-Authors: Véronique Desrosiers, Nathalie R. Le François, Pierre U. BlierAbstract:ABSTRACT A trypsin-like enzyme was recovered from Atlantic wolffish (Anarhichas Lupus) viscera and its properties were compared with those of commercially available bovine trypsin. Trypsin-like purification was carried out by a combination of sulphate ammonium fractionation, acetone precipitation, and ultra-filtration on 100 kDa and 50 kDa NMW membranes. Assays reveal that both sources of enzymes displayed similar pH range optima (pH 7–10) and similar activity profiles with increasing temperature. The wolffish trypsin-like enzyme mainly differed from bovine trypsin by its thermal and alkaline stability. Atlantic wolffish appear to be an interesting source of digestive proteases with unique properties that could be used in food biotechnology.
-
High antifreeze protein levels in wolffish (Anarhichas Lupus) make them an ideal candidate for culture in cold, potentially ice laden waters
Aquaculture, 2007Co-Authors: Mariève Desjardins, Nathalie R. Le François, Garth L. Fletcher, Pierre U. BlierAbstract:Abstract This study was designed to determine whether juvenile Atlantic wolffish (Anarhichas Lupus) cultured at optimal temperatures for growth (9–12 °C) were fully capable of producing high concentrations of plasma AFP when exposed to the low water temperatures. A twelve month cycle of plasma AFP activity was examined in juvenile wolffish (1+and 2+) initially raised in heated water and then exposed to either a constant regimen of warm water or a seasonal cycle of water temperatures. The results indicate that juvenile wolffish exposed to a seasonal cycle of water temperatures produced high levels (approximately 12 mg/ml) of AFP when the temperatures declined to low levels. Moreover, the levels of antifreeze found in juveniles were similar to those observed in adult wolffish. Wolffish kept in warm-water conditions produced little or no AFP. It appears that the thermal regimen can be manipulated to enhance growth rates without compromising the ability to produce AFP and thus tolerance to sub-zero temperatures. On-growing of the juveniles under warm water temperatures conditions will not reduce the yield of AFP that can be obtained at harvest.
Dimitri A. Pavlov - One of the best experts on this subject based on the ideXlab platform.
-
Features of Transition from Larva to Juvenile in Fishes with Different Types of Early Ontogeny
Environmental Biology of Fishes, 1999Co-Authors: Dimitri A. PavlovAbstract:The transition from the larva state to the juvenile state (i.e. morphological condition characterised by mainly adult characters) was examined in three marine fish species: herring Clupea pallasi marisalbi, wolffish Anarhichas Lupus, and eelpout Zoarces viviparus, based on external morphology and skeletal development. In spite of the different reproductive styles (oviparity, facultative viviparity, and obligate viviparity, respectively) and different types of early ontogeny (indirect, transitory, and direct, respectively), the beginning of the juvenile state occurred at similar total lengths (TL), which were approximated as 35 mm TL in herring and eelpout, and 32 mm TL in wolffish. Features of ontogeny were compared, assuming that the beginning of the juvenile state represented an uniform characteristic of morphological development for these species. It was proposed that the beginning of the larva or juvenile periods (sensu Balon) could not coincide with the beginning of the larva and juvenile states in the ontogeny of some species.
-
Effects of water temperature on protein synthesis and protein growth in juvenile Atlantic wolffish (Anarhichas Lupus)
Canadian Journal of Fisheries and Aquatic Sciences, 1999Co-Authors: Ian D. Mccarthy, Dimitri A. Pavlov, Erlend Moksness, Dominic F. HoulihanAbstract:The effects of water temperature (5, 8, 11, and 14°C) on the fractional rate (percent per day) of protein consumption (kr) and on white muscle and whole-body fractional rates of protein synthesis (...
-
The effects of temperature on growth rate and growth efficiency of juvenile common wolffish
Aquaculture International, 1998Co-Authors: Ian Mccarthy, Erlend Moksness, Dimitri A. PavlovAbstract:The effects of temperature on the survival, growth rate and growth efficiency of larval and juvenile common wolffish, Anarhichas Lupus L. were studied at 0–31 days and 9–12 months post-hatching, respectively. The influence of temperature regime during egg incubation on subsequent survival and growth was also examined. The fish were reared at constant water temperatures of 5, 8, 11 and 14°C, and all groups were fed dry pellets. At age 1 month, maximum growth rates were observed at 11 and 14°C. Growth rates and survival of early juveniles were dependent upon incubation history, high growth being obtained only if rearing temperature exceeded the temperature of egg incubation. In juveniles at age 9–12 months, the relationships between temperature and growth, and temperature and growth efficiency were parabolic: the optimum water temperatures for growth (Topt.G) and growth efficiency (Topt.GE) were 11°C and 9.7°C respectively. The growth rate and growth efficiency at these water temperatures were 0.9% day–1 and 0.45 g weight gain per g food offered, respectively. © Rapid Science Ltd. 1998
-
Development of the axial skeleton in wolffish, Anarhichas Lupus (Pisces, Anarhichadidae), at different temperatures
Environmental Biology of Fishes, 1997Co-Authors: Dimitri A. Pavlov, Erlend MoksnessAbstract:The ontogeny of the axial skeleton, in particular the caudal skeleton, is described from embryos to adult specimens in common wolffish, Anarhichas Lupus. The eggs were incubated at constant temperatures of 7.0, 11.0 and 13.0 °C. High egg mortality and structural changes in skeletal development (fusion of parts, absence of distal radials and most of dorsal and anal fin rays, abnormal neural arches and dorsal fin rays) were observed at 13 °C. The frequencies of some anomalies were lower at 11 °C than at 13 °C. The main reason of structural changes of the skeleton at high temperature is the breaking of normal correlations between developmental rates of some cartilaginous structures and other tissues and organs of the embryo. These data suggest an epigenetic mechanism of skeletal evolution.
-
Spermatozoon ultrastructure and sperm production in wolffish (Anarhichas Lupus), a species with internal fertilization
Aquatic Living Resources, 1997Co-Authors: Dimitri A. Pavlov, Pål Knudsen, Natal'ya G. Emel'yanova, Erlend MoksnessAbstract:L'ultrastructure du spermatozoide et la production de sperme ont ete observees chez le poisson-loup (Anarhichas Lupus), une espece a fecondation interne, a partir d'un elevage. Le spermatozoide, arrive a maturite, a une tete allongee et un flagelle excentre, et un corps intermedaire comparativement bien developpe. La longueur moyenne de la tete du spermatozoide et du flagelle sont 3,3 et 21,2 μm respectivement. La taille des cellules du sperme est tres variable, due a la presence de spermatides et de spermatozoides degeneres. Chez la plupart des mâles, la production de sperme a ete observee tout au long de l'annee avec un pic d'abondance en decembre et en janvier. La production de sperme diminue a la fin de la saison de reproduction. La difference de volumes de l'ejaculat et du sperme entre mâles gardes sous deux cycles differents d'eclairement (18 h nuit: 6 h jour et inversement) n'etait pas significative. Les caracteristiques du sperme du poisson-loup sont comparees aux donnees bibliographiques d'autres poissons a fecondation interne et externe.
Nathalie R. Le François - One of the best experts on this subject based on the ideXlab platform.
-
Photoperiod manipulation for the reproductive management of captive wolffish populations: Anarhichas minor and A. Lupus
Aquaculture International, 2018Co-Authors: Bernard-antonin Dupont Cyr, Helge Tveiten, Domynick Maltais, Grant W. Vandenberg, Nathalie R. Le FrançoisAbstract:This study provides new and practical information to implement the use of photoperiodic manipulation for the control of the sexual maturation of Canadian 6^+ Atlantic wolffish ( Anarhichas Lupus ) and 3^+ first-time spawners spotted wolffish ( Anarhichas minor ) from Canadian and Norwegian populations. Wolffish reproductive cycle (gametogenesis and oocyte maturation and spermiation) was monitored for 23 consecutive months. Control groups were held under a 12-month simulated natural photoperiod and treatment groups under an 8-month compressed photoperiod. Plasma sex steroid concentrations (estradiol-17β and 11-ketotestosterone), oocyte diameter growth, and milt production were assessed monthly. For all groups under study, fish subjected to the compressed photoperiod spawned 2–6 months earlier than the controls. Complete out-of-shift cycle was not achieved based on the completion of two reproduction cycles, and this is briefly discussed. Photoperiod treatment induced temporal shifts in sex steroid profiles, which are the likely mediators of altered timing of ovulation/final maturation. Photoperiod has a strong influence on the timing of wolffish maturation and could be used as an efficient and inexpensive tool to secure wolffish reproduction operations (year-round supply of egg and milt and/or timing with optimal temperature regimes).
-
Purification and partial characterization of vitellogenin from spotted wolffish (Anarhichas minor) and development of an enzyme-linked immunosorbent assay for the determination of gender and sexual maturity.
Fish physiology and biochemistry, 2013Co-Authors: Domynick Maltais, Bernard-antonin Dupont Cyr, Robert L. Roy, Nathalie R. Le FrançoisAbstract:Vitellogenin (VTG) from spotted wolffish, Anarhichas minor, a candidate species for cold-water marine aquaculture, was purified by MgCl2/EDTA precipitation followed by a two-step chromatographic procedure. VTG had an apparent molecular mass of 470 kDa, as determined by gel filtration, and an amino acid composition similar to those of other teleosts. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of the purified VTG revealed a major band with a relative molecular weight of 166 kDa and some minor bands. Spotted wolffish VTG (sw-VTG) is relatively robust to in vitro degradation, as shown when samples of purified VTG and plasma from mature females subjected to various storage conditions or multiple freeze/thaw cycles were analyzed by Western blot. We developed an indirect competitive enzyme-linked immunosorbent assay (ELISA) using an antibody against Atlantic wolffish (Anarhichas Lupus) VTG and purified sw-VTG. The ELISA had a detection limit of 6.7 ng/ml and a working range of 16.2–787.5 ng/ml, with intra- and inter-assay coefficients of variation ranging from 1.5 to 7.3 % and 7.1 to 14.3 %, respectively. The assay could distinguish males from immature females and discriminate maturing females at different stage of oocyte development. These results suggest that the sw-VTG ELISA would be useful in spotted wolffish aquaculture to determine sex and monitor female maturation.
-
Characterization of the early-stages of the wolffish hybrid Anarhichas minor × Anarhichas Lupus : conservation and aquaculture applications
Aquatic Living Resources, 2009Co-Authors: Catherine M. Gaudreau, Nathalie R. Le François, Helge Tveiten, Delphine Ditlecadet, Pierre U. BlierAbstract:This is the first report of early-life developmental characteristics (coloration pattern, growth and survival) and genetic identification of the wolffish interspecific hybrid between Anarhichas minor and A. Lupus, both endangered species in Canadian coastal water and of interest for cold-water aquaculture diversification. A first growth trial at 8 ◦ C featuring pure strains A. minor and the hybrid A. minor × A. Lupus in triplicates was conducted in 2006 during the period from 0 to 140 days post-hatch. A second growth trial was runned in 2007 featuring A. minor, A. Lupus and the reciprocal hybrids A. minor × A. Lupus and A. Lupus × A. minor. Egg development indicators and early-hatching characteristics are reported.
-
Trypsin-Like Enzyme from Atlantic Wolffish (Anarhichas Lupus) Viscera: Purification and Characterization
Journal of Aquatic Food Product Technology, 2008Co-Authors: Véronique Desrosiers, Nathalie R. Le François, Pierre U. BlierAbstract:ABSTRACT A trypsin-like enzyme was recovered from Atlantic wolffish (Anarhichas Lupus) viscera and its properties were compared with those of commercially available bovine trypsin. Trypsin-like purification was carried out by a combination of sulphate ammonium fractionation, acetone precipitation, and ultra-filtration on 100 kDa and 50 kDa NMW membranes. Assays reveal that both sources of enzymes displayed similar pH range optima (pH 7–10) and similar activity profiles with increasing temperature. The wolffish trypsin-like enzyme mainly differed from bovine trypsin by its thermal and alkaline stability. Atlantic wolffish appear to be an interesting source of digestive proteases with unique properties that could be used in food biotechnology.
-
High antifreeze protein levels in wolffish (Anarhichas Lupus) make them an ideal candidate for culture in cold, potentially ice laden waters
Aquaculture, 2007Co-Authors: Mariève Desjardins, Nathalie R. Le François, Garth L. Fletcher, Pierre U. BlierAbstract:Abstract This study was designed to determine whether juvenile Atlantic wolffish (Anarhichas Lupus) cultured at optimal temperatures for growth (9–12 °C) were fully capable of producing high concentrations of plasma AFP when exposed to the low water temperatures. A twelve month cycle of plasma AFP activity was examined in juvenile wolffish (1+and 2+) initially raised in heated water and then exposed to either a constant regimen of warm water or a seasonal cycle of water temperatures. The results indicate that juvenile wolffish exposed to a seasonal cycle of water temperatures produced high levels (approximately 12 mg/ml) of AFP when the temperatures declined to low levels. Moreover, the levels of antifreeze found in juveniles were similar to those observed in adult wolffish. Wolffish kept in warm-water conditions produced little or no AFP. It appears that the thermal regimen can be manipulated to enhance growth rates without compromising the ability to produce AFP and thus tolerance to sub-zero temperatures. On-growing of the juveniles under warm water temperatures conditions will not reduce the yield of AFP that can be obtained at harvest.
Á. Gunnarsson - One of the best experts on this subject based on the ideXlab platform.
-
Spatio-temporal variability in fecundity and atresia of Atlantic wolffish (Anarhichas Lupus L.) population in Icelandic waters
Fisheries Research, 2017Co-Authors: Á. GunnarssonAbstract:Abstract Biological data were retrieved from 374 female Atlantic wolffish ( Anarhichas Lupus ) collected from 2001–2006 at A. Lupus main spawning grounds in Iceland and at two other locations with different sea temperature regimes to investigate spatial and temporal difference in fecundity and indications of atresia. There was no spatial difference in fecundity but temporal difference was found, and fecundity decreased in time, clearly indicating the presence of atresia. A. Lupus that was 57 cm long was 11% more fecund in the year 2003 than in 2005. Egg numbers decreased about 20% from June to October for 67 cm long A. Lupus . There was a positive relationship between fecundity and condition of the fish.
-
Atlantic wolf-fish Anarhichas Lupus population diversity: growth and maturation.
Journal of fish biology, 2014Co-Authors: Á. GunnarssonAbstract:Biological data from 1125 female Atlantic wolf-fish Anarhichas Lupus were collected during 2002-2006 at their main spawning and fishing grounds in Iceland. The results demonstrated substantial annual variation in growth and maturity of female A. Lupus. The fast growing females mature earlier than the slow growing ones. In addition, females mature at a larger size and greater age in warmer temperatures than colder ones. There was a strong negative relationship between temperature and growth, which may indicate that the sea temperature west of Iceland has risen above the optimum for growth of female A. Lupus and thereby reduced the reproductive potential of the species.
-
Growth, maturity and fecundity of wolffish Anarhichas Lupus L. in Icelandic waters
Journal of Fish Biology, 2006Co-Authors: Á. Gunnarsson, E. Hjörleifsson, K. Thórarinsson, Gudrun MarteinsdottirAbstract:Fecundity, maturity and the relationship between growth and maturity of common wolffish Anarhichas Lupus were studied in Icelandic waters. A total of 788 female common wolffish were sampled in two areas: one in the relatively warm sea west of Iceland and the other in the colder sea east of Iceland. No difference was detected in fecundity of common wolffish between areas. The time from the onset of the cortical alveolus stage until spawning, was on average, 10 years in the east and 8 years in the west area. Common wolffish in the east area reached cortical alveolus stage, on average, at a greater age but similar size compared to common wolffish in the west area. Similarly, common wolffish started spawning, on average, at greater age and larger size in the east than in the west area. Common wolffish grew faster in the west than in the east area. Spawning common wolffish grew faster than common wolffish at the cortical alveolus stage in both areas. The relationship between growth and maturity for common wolffish in Icelandic waters appeared to be related to temperature, characterized by fast growth and early maturation in the west and slower growth and delayed maturation in the east.