Muksun Research Articles

Fatty acid composition of two small fish in the Gyda River (Kara Sea Basin, Northwestern Siberia, Russia)

The fatty acid composition of the flesh of rainbow smelt (RS, Osmerus mordax) and ruffe (RF, Gymnocephalus cernuus), two small fish species inhabiting the Gyda River (Siberia, Russia), was assayed using a gas-liquid chromatographic method with an ionization detection system and high efficiency capillary columns. RS was found to be richer in the total fatty acid content than RF (21.5 vs. 7.07 mg g–1). The proportion of saturated fatty acids (SFA) was similar in the fish studied (29.2 % in RS and 29.6 % in RF) whereas the flesh of RS contained a higher proportion of monounsaturated fatty acids, MUFA (42.2 vs. 13.9 %), and a lower proportion of polyunsaturated fatty acids, PUFA (28.6 vs. 56.5 %) than RF. RS is rich in essential n-3 PUFAs (2610 and 2390 μg g–1 for docosahexaenoic and eicosapentaenoic acids, respectively). In RF, the atherogenic index (0.39) and thrombogenic (0.20) index were lower than in RS (0.59 and 0.27, respectively). The fatty acid profile of RS in the study area differed from that reported for the flesh of this species from a Canadian estuary probably due to substantial differences in the diet of RS in these habitats. A comparison among fish species from the Gyda River indicated that in terms of nutrition indices, RS has the highest similarity with the muksun Coregonus muksun while RF is closely related to the northern pike Esox lucius. Based on the results from this study, both RF and RS can be recommended for human consumption. In particular, RS may be used as a replacement for muksun, an overfished species, in the traditional diet of indigenous peoples in northwestern Siberia.

ECOLOGICAL ASPECTS OF EXPERIMENTAL GROWING OF YOUNG MUKSUN IN THE NATURAL ENVIRONMENT

The feeding characteristics of juvenile muksun Coregonus muksun (Pallas, 1814) when reared in cages installed on the Lower Ob channel are considered. It has been established that, along with artificial food, juveniles feed on zoobenthos and zooplankton organisms that enter the cages during drift. Their consumption was noted from the first to the last days of growing. The bulk of the mass of the food bolus was artificial food – 88.3–94.3%; aquatic invertebrates accounted for 1.3–5.7% of the mass of the food bolus. Chironomid larvae dominated. There were no statistically significant differences in the consumption of invertebrate animals by muksun juveniles before and after feeding (p = 0.442) with average values of 0.005 and 0.006 g, respectively. The ability of juveniles to transition from artificial to natural food supply at all stages of development was noted, which is an indicator of successful adaptation to environmental conditions during cage rearing in the channels of the river Obi.

Study of the Features of Natural Mortality Iin Muksun and Peladi of the Ob River by Constructing Dependences of the Number of Their Generations

It is shown that it is possible to determine the natural mortality of fish, using the example of muksun (Coregonus muksun) and peled (Coregonus peled) of the Ob River, by constructing dependences of the decrease in the number of generations. It is established that the dynamics of mortality has a U-shaped form. The minimum mortality rates are at the age when sexual maturity reaches more than 70% of individuals. The influence of various natural and anthropogenic factors on natural mortality is shown. It is noted that periodically occurring deficiency of dissolved oxygen has a significant impact on the wintering fish in the southern part of the Gulf of Ob. There was an increase in mortality during fish migrations and this fact can serve as one of the criteria for the periodicity of whitefish spawning. It is established that numerous generations of favorable years of feeding and reproduction are characterized by a higher survival rate of individuals. The presence of genera-tions with different degrees of survival is an important adaptive property of populations.

The content of zinc and selenium in local food products of Yakutia

Deficiency of the necessary complex of micronutrients under abnormal nutrition structure creates a problem for the preservation of health and performance of the population. In this regard, it is very relevant to develop a science-based strategy for the consumption of traditional Yakut national food that have a high nutritional value and are able to satisfy the requirements of the human body in micronutrients. The purpose of the research was to investigate the content of selenium and zinc in the local foods which are most commonly consumed by the population of Yakutia. Material and methods. The objects of study were meat (7-9 cuts each) and offal (9-11 species each) of the Yakut cattle breed (2 bulls at the age of 2.5 years), of the Yakut horse foals (3 heads at the age of 6 months), northern domestic deer (3 heads), and whitefish (Coregonus muksun), Yakut crucian carp (Carassius carassius jacuticus), lake minnow [Phoxinus percnurus (Pallas)] (3 kg each). The trace elements, zinc and selenium, were determined by infrared spectroscopy. Results. The greatest amount of zinc in the meat of farm animals was noted in the meat of Yakut cattle (6.8±0.3 mg/100 g) and Yakut horse foals (6.7±0.2 mg/100 g), and the lowest - in the meat of domestic reindeer (1.5±0.1 mg/100 g). In terms of selenium content, the meat of domestic reindeer had the highest indicators (37.0±1.0 μg/100 g), and the meat of Yakut cattle had the lowest (19.0±0.8 μg/100g). The highest concentration of zinc and selenium was found in by-products of reindeer: zinc level in the heart and liver was 12.8 mg/100 g, in the small intestine and rennet - 19.0-20.4 mg/100 g, selenium level in the colon and rennet was 41.0-46.7 μg/100 g. The content of zinc and selenium in the fresh-water muksun belly (2.14±0.08 mg and 45.0±1.8 μg in 100 g) was 32.3-37.2% higher than in the fillet of muksun, and selenium level was 3 fold higher than in the Yakut carp and in the lake minnow. The consumption of 100-200 g of meat or by-products of Yakut cattle, Yakut horse foals, by-products of reindeer or Yakut crucian carp can fully cover the daily requirement of an adult in zinc. The consumption of 200 g of venison or muksun completely covers the daily need for selenium, while the portion of the other studied products contains about half or more of recommended daily intake of this trace element. Conclusion. The data presented in the article show that the population of Yakutia, with a rational diet with local products, can meet the requirements in selenium and zinc in accordance with physiological needs.

РЕТРОСПЕКТИВНЫЙ АНАЛИЗ ИХТИОФАУНЫ РЕКИ ТОМЬ В ПРЕДДВЕРИИ СТРОИТЕЛЬСТВА КРАПИВИНСКОГО ВОДОХРАНИЛИЩА

The resumption of design and survey work for the construction of the Krapivinsky Hydroelectric Power Plant on the Tom River has necessitated the assessment of the current state of its fish resources and called for making the prediction of their transformation in the event of the hydroelectric complex being put into operation. In the early 20th century, the Tom River was classified as a salmonid habitat. At that time, such valuable commercial species as the Siberian taimen Hucho taimen, blunt-snouted lenok Brachymystax tumensis , tugun Coregonus tugun, humpback whitefish Coregonus pidschian, Nickolsky’s grayling Thymallus nikolskyi , nelma Stenodus leucichthys nelma, muksun Coregonus muksun, and peled Coregonus peled were permanent residents. Sturgeons, such as the Siberian sturgeon Acipenser baerii and sterlet Acipenser ruthenus, were also abundant. Currently, out of these species, grayling, occasionally taimen and lenok are caught in the Tom River; the common roach Rutilus rutilus , European perch Perca fluviatilis, Siberian dace Leuciscus baicalensis and Eurasian ruffe Gymnocephalus cernuus comprise 95 % of all fish caught. If construction of the Krapivinsky Reservoir on the Tom River is completed and it is put into operation, a deep-water, slow-flowing “lake-type” water body will be created. The river bed will be blocked, so semi-anadromous fish species, many of which are listed in the Red Data Book-such as Siberian sturgeon, sterlet and nelma,-will disappear. A decrease in the abundance of grayling, taimen and lenok, already low in number, should also be expected. These fish species winter in the pits, some of them migrate to the Ob River, so, after passing the spillway, they will not be able to return upstream to the spawning grounds. The abundance of lake and lake-river species is expected to increase, among them the common roach, dace Leuciscus leuciscus , European perch, Prussian carp Carassius gibelio (introduced locally, subsequently self-dispersed), as well as common bleak Alburnus alburnus and sunbleak Leucaspius delineates (accidental invaders). In the future, it is possible to make an attempt to introduce peled to the upper basin of the Krapivinsky Reservoir. There is a prospective threat of the Chinese sleeper Perccottus glenii spreading in the upcoming reservoir, which can severely undermine its fish stocks.

Catches, size and age composition of the spawning stock muksun Coregonus muksun in the Middle Ob (Tomsk region)

Muksun Coregonus muksun is one of the most valuable whitefish species. It lives in large rivers of Siberia. This is a typical semi-anadromous species. There are presents data on the catches of muksun in the Middle Ob (on spawning grounds and migration routes to them), which generally reflects the number of spawning stock of this species rising to spawn. It is shown that in the middle of the 20th century the catches of muksun averaged 47 tons per year. In the early 1970s, there was a sharp short-term increase in its catches to an average of 215 tons per year, which may be caused by the start of intensive work on collecting whitefish caviar in the area of their spawning run for obtain fish stock for pasture aquaculture in the lakes of Western Siberia. Since the early 1980s, muksun catches have fallen catastrophically, and its fishing is currently prohibited. On the spawning grounds of the Middle Ob, specimens under the age of 16+ were noted. Until the end of the 1990s, the age and size composition of the Muksun spawning stock remained relatively stable. In recent years, there has been an increase of younger fish and, accordingly, a decrease in the average size of fish in the catches. At present (2017–2019), specimens with a fishing length from 392 to 523 mm (on average 457 mm) and a weight of 747 to 1915 g (on average 1233 g) have been noted in the catches of muksun.

Fatty Acid Content of Four Salmonid Fish Consumed by Indigenous Peoples from the Yamal-Nenets Autonomous Okrug (Northwestern Siberia, Russia).

Simple SummaryFish is an important source of nutritious fatty acids, which are necessary for the prevention of cardiovascular and neurological diseases. Many fish species are a major component of the human diet, especially for indigenous peoples from Siberia, Russia, but information about their fatty acid profiles is scarce. We studied the fatty acid content of four salmonid fish (Arctic cisco, least cisco, muksun, and Arctic charr) inhabiting water bodies of the Gydan Peninsula, Kara Sea basin. We found a high content of essential polyunsaturated fatty acids in local salmonid fishes. Arctic charr was the fish species with the highest concentration of fatty acids in the flesh. The results of our multivariate analysis may be useful for anglers, stakeholders, and local consumers.We assayed fatty acids in the flesh of Arctic cisco Coregonus autumnalis (adult and juvenile), least cisco Coregonus sardinella, muksun Coregonus muksun, and Arctic charr Salvelinus alpinus inhabiting water bodies of the Gydan Peninsula, Siberia, Russia. The highest concentrations of total and polyunsaturated fatty acids (PUFAs) were found in Arctic charr (27.8 and 9.5 mg g−1) and adult Arctic cisco (20.2 and 7.6 mg g−1), while the lowest concentrations occurred in juvenile Arctic cisco (7.5 and 3.6 mg g−1). Multivariate analyses divided all studied fish into five distinct groups with the highest similarity between least cisco and muksun and the highest dissimilarity between juvenile Arctic cisco and Arctic charr. Coregonid fish from the study area had a higher content of docosahexaenoic and eicosapentaenoic acids than their conspecifics from subarctic and temperate habitats. The flesh of the studied fish is a source of a healthy diet for humans. Taking into account that all the studied fish are components of the traditional diet of indigenous peoples in northwestern Siberia, our data may be useful not only for local consumers and anglers but also for stakeholders focused on food policy and food security in the area.

Growth of Muksun Coregonus muksun in Different Water Conditions in the Ob River (Russia)

Growth of Muksun Coregonus muksun in Different Water Conditions in the Ob River (Russia)

Overview of the fish fauna of the Chaunskaya basin – the area of the natural reserve "Chaunskaya Guba" and the port of Pevek (East Siberian Arctic)

The fishes of the Chaunskaya Bay and its Basin have been little studied. Part of the coast of this vast Arctic estuary (about 9 thousand km2) is included in the state nature reserve “Chaunskaya Guba”; at the entrance to the bay there is the seaport of Pevek, a transit hub of the Northern Sea Route. The area has been identified as one of the priorities for the protection of biodiversity in the seas of the Russian Arctic. Solving the problem of biota conservation begins with an inventory of the fauna. The paper presents the results of summarizing data on the species composition of marine, anadromous and freshwater fishes in the Chaunskaya Bay and its basin. The updated list includes 36 species of 28 genera, 16 families and 10 orders. In marine waters there are 31 species (18 marine, 13 anadromous and semi-anadromous fish), in rivers and lakes there are 5 freshwater (and 13 anadromous and semi-anadromous) species. The Muksun Coregonus muksun (Pallas, 1814) and the pike Esox lucius Linnaeus, 1758, which were absent in the fauna lists, are added. The lamprey Lethenteron kessleri (Anikin, 1905), the Pacific herring Clupea pallasii Valenciennes, 1847, and the Arctic charr Salvelinus alpinus (Linnaeus, 1758), which were previously recorded, are not confirmed by reliable findings. The marine fish community of the Chaunskaya Bay is an impoverished shelf fauna of the East Siberian Sea and includes species adapted to desalination. The freshwater ichthyofauna of the basin differs from the fauna of the neighboring Kolyma River region in the loss of a number of freshwater species, which are believed to have been extinct because of the Holocene cooling. A significant part of the fish complex consists of elements of the North Pacific fauna that spread to the East Siberian Sea in the postglacial period.

Comparative Characteristics of the Size–Weight Parameters and Lipid Composition of Wild and Cultured Eggs of the Muksun Coregonus muksun (Pallas, 1814)

Comparative Characteristics of the Size–Weight Parameters and Lipid Composition of Wild and Cultured Eggs of the Muksun Coregonus muksun (Pallas, 1814)

Genetic differentiation of Coregonus muksun in natural populations and broodstocks of fish rearing farms “Forvat” and “Sobsky” in relation to the problem of restoring the species population in Western Siberia

With regard to the problem of restoring the muksun (Coregonus muksun) population in Western Siberia by means of artificial regeneration, the genetic differentiation of natural populations and broodstocks of fish rearing farms “Forvat” and “Sobsky” was studied. Eighty-four sequences of mtDNA (3,006 bp) containing the highly polymorphic genes ND1 and ND2 were analysed. The differences between the populations of Western and Eastern Siberia were revealed. These findings must be taken into account when attempting to restore the species population in each particular region. The genetic closeness of the muksun from fish rearing farms “Forvat” and “Sobsky” with muksun from the Ob-Taz basin gives grounds for using these broodstocks for seeding the Ob and Taz rivers.

INVASION OF FISH BY LARVAE OF THE FAMILY DIPHYLLOBOTHRIIDAE IN THE KHANTY-MANSI AUTONOMOUS OKRUG – YUGRA

Two epidemiologically significant species of the tapeworm (D. latum и D. dendriticum) circulate in of the Ob-Irtysh basin within the Khanty-Mansi Autonomous Okrug. They have an unequal effect on the human body. The purpose of the science work is to determine the invasion of fish by larvae of tapeworms D.latum and D.dendriticum (Perch Perca fluviatilis, Ruff Gymnocephalus cernuus, Pike Esox lucius, Syrok Coregonus peled, Muksun Coregonus muksun, Nelma Stenodus leucichthys nelma) from waterbodies of the Ob River and its tributaries from 2013 to 2019 year. The study aim is to identify the main factors of transmission of the invasion (diphyllobothriasis) to population. The fish for parasitological research and species identification was caught in the Ob River and its tributary, the Vakh River, as well as Torm-Emtor Lake. The studies were carried out in the parasitological laboratory of the Center for Hygiene and Epidemiology in the Khanty-Mansi Autonomous Okrug – Yugra, Nizhnevartovsk, the Nizhnevartovsk District, in Megione and Raduzhny by the method of incomplete helminthological study of fish. The study results found in general a very high level of plerocercoid invasion of fish from the Ob and Vakh Rivers. It was noted that the pike had a significantly high percentage of infection with D. latum, 71.64%. The highest intensity of invasion and localization of larvae (the family Diphyllobothriidae) was on the abdominal wall of the fish, and then on walls and in the thickness of walls of esophagus and stomach, in eggs, and very few in muscle tissues.

Results of a secular study of some features of the biology of the muksun population Coregonus muksun of the Ob-Irtysh basin

Muksun spawned in the Ob River and its tributaries and overwintered in the river and in the Ob Bay, making various migrations. Under the influence of anthropogenic factors, there was a decrease in the number, to the threat of almost complete disappearance of the population. A retrospective systemic analysis of the peculiarities of the existence of the muksun population should become the basis for a strategy for its restoration and rational use.

Biochemical Composition and Nutritional Value of Muksun in the Lower Lena River

Studies were carried out to determine the biochemical composition and nutritional value of muksun (Coregonus muksun (Pallas)) in the lower reaches of the Lena River. This is a valuable commercial fish; 90% of its total catch in Yakutia is covered by the Lena River, while its abundance is low in other rivers and continues to decrease due to overfishing. The average annual catch of muksun is 450 t and its total allowable catches are 510–590 t in Yakutia. It is noted that the fillet and belly of muksun are considered protein products in terms of protein content (15–20%). Thus, the protein content was 16.05 ± 0.003% in its fillet and 18.72 ± 0.009% in its belly. With respect to the fat content in the belly (22.67 ± 0.009%), muksun is a particularly fatty fish variety (over 15%). With respect to the nutritional value, muksun is considered a high-calorie food product (over 200–300 kkal/100 g). The proteins of the muksun fillet and belly have a high biological value, since the amount of amino acid score is higher than the ideal protein standard (over 100%). This research gives grounds to classify muksun meat as a high-quality and well-balanced food product.

Morphological and Genetic Diversity of Two Forms of Muksun Coregonus muksun (Salmonidae) of the Khatanga River Basin as a Key for Understanding the Phylogenetic Relationships between Muksun and Whitefish C. lavaretus

Morphological analysis of muksun Coregonus muksun of the Khatanga River basin revealed that along with its typical high-density-rakered form, individuals of the low-density-rakered form also live in this region. Analysis of the genetic polymorphism of three marker regions of mitochondrial (ND1 and COI fragments) and nuclear (ITS1) DNA indicates the polyphyletic origin of these forms. The revealed low level of genetic differentiation of muksun and whitefish C. lavaretus, along with the available data on the absence of clear diagnostic species characteristics, suggest that they belong to the same biological species C. lavaretus.

Structure of the yolk syncytial layer in the larvae of whitefishes: A histological study

The yolk syncytial layer (YSL) is a symplastic provisory system that forms at the early stages of embryogenesis of teleosts. The YSL serves morphogenetic, trophic, and immune functions. Despite its important role in development, data on the structure of YSL is scarce. In the present study, comparative histological research on the features of YSL structure in the development of larvae of four economically important species of Coregonidae (Salmoniformes)—Coregonus peled, Coregonus muksun, Coregonus nasus, and Stenodus leucichthys nelma—is presented. The YSL of the larvae of Coregonidae has a complex, differentiated structure. Functional regionalization of YSL cytoplasm, possibly determined by the specific features of nutrient assimilation, is typical for all aforementioned species. Cytoplasm that encircles a large oil globule appears striated. A division into an inner area, filled with yolk inclusions, and an outer, smoother homogeneous area, can be noted in the cytoplasm surrounding the yolk mass. The oil globule is retained after complete utilization of the yolk mass. The inequality of thickness of YSL along anteroposterior and dorsoventral axes also indicates the functional regionalization. The dorsomedial area of YSL, located under the intestine, is the least thick. Dorsolateral areas are strongly incrassated and envelop the intestine from two sides. Gigantic nuclei of exceptionally complex form are typical for YSL. Specific features apply to the form of YSL and its nuclei. Based on the obtained results, a fundamental similarity in organization of the YSL of larvae of the studied whitefishes can be concluded; however, its specific variations distinguishable on a histological level can be discussed.

Seasonal variability of some biochemical parameters in the whitefish (Coregonus muksun and Coregonus lavaretus)

The base levels and seasonal variability of ethoxyresorufin-O-deethylase (EROD) activity, glutathione-S-transferase (GST) activity, reduced glutathione concentration (GSH) and phospholipids concentration (PhL) of Coregonus lavaretus (Linnaeus, 1758) and Coregonus muksun (Pallas, 1814) were investigated. The relationships between this biochemical markers, hepatosomatic index and seasonal growth were also examined.

Cytogenetic biomarkers for the assessment of the influence of pollution on natural fish populations

Cytogenetic analysis methods were used to study the developing embryos of the following four Coregonidae species: Coregonus peled (Gmelin), Coregonus lavaretus (Gmelin), Coregonus nasus (Pallas) and Coregonus muksun (Pallas). Spawners of these species were selected from rivers and lakes of the Tyumen region (Russia) with different levels of pollution. The variability of the chromosomal aberration rate was analyzed during a monitoring period of more than 20 years. The level of chromosomal mutability in the embryonic cells of these fishes was found to have steadily increased during the observation period (1989–2011). The higher frequency of chromosomal mutations at different stages of embryogenesis in broad whitefish, C. nasus (Pallas), was noted in comparison with other species. The possible use of chromosomal mutation frequency as an indicator (biomarker) to characterize the state of a population is discussed.

Mitochondrial DNA genetic differentiation of the muksun Coregonus muksun (Pallas) and related Siberian species of Coregonus (Coredonidae, Salmoniformes)

Restriction enzyme analysis of the mitochondrial DNA (mtDNA) fragment encoding subunit 1 of the NADH dehydrogenase complex (ND-1) amplified via polymerase chain reaction (PCR) has been used to obtain data on genetic differentiation of muksun Coregonus muksun (Pallas) populations. Population polymorphism with respect to the restriction sites of 18 endonucleases has been described. It has been demonstrated that the muksun is genetically related to the pidschian C. pidschian (Gmelin), its sympatric species in Siberian waters. Analysis of the median network of mtDNA haplotypes has shown that haplotypes of muksun from various Siberian basins form a common group with haplotypes of pidschian of the Arctic Ocean basin, some frequent haplotypes been found in both forms. This raises the question as to the validity of the muksun as a species. Differences within this group of haplotypes are much smaller than those typical of species of the genus Coregonus. The possibility of a hybrid origin of the muksun from a pidschian-like ancestor and species of the cisco-peled (C. sardinella-C. peled) complex is discussed.

Selection and criteria for biological indicator species for Arctic monitoring

The estuarine ecosystems are considered as key objects in the Arctic monitoring. Crustacean Saduria entomon, bivalve Portlandia aestuariorum and Cyrtodaria curriana, whitefish Coregonus muksun, C. autumnalis and C. sardinella sardinella and sculpin Triglopsis polaris (= Myoxocephalus quadricornis) are proposed for monitoring of Arctic estuaries. Review of AMAP list of species was carried out. Some species, as included in the World and National ‘Red Books’ and thus being under legislation (polar bear, atlantic and Laptev sea subspecies of walrus, falcon Falco rusticolus) must be left out of the list of species-monitors. The same is applied as in the case of species which often feed on human waste (glaucous gull, fulmar). Instead of using the rare and valuable carnivorous species, appropriately their prey is used as monitors.