Weatherfish Misgurnus Fossilis Research Articles

Ichthyofauna of the Bilotserkivskyi lower reservoir on the Ros river

The composition of ichthyofauna of Ukraine is changing due to natural processes and the influence of anthropogenic factors in the internal water bodies. Systematic analysis of changes allows controlling these processes and maintaining the diversity of species at a constant level. The purpose of the study was to investigate changes in the composition of the ichthyofauna of the Bilotserkivskyi lower reservoir (Ros River) after the discharge of industrial waste of the Bilotserkivvoda enterprise in 2017 and 2020, which led to the mass death of fish and crayfish. The studies were conducted by catching fish with species identification and a survey of fishermen from November 2016 to October 2020. Additionally, the species composition of fish in this section of the Ros River was considered before the reservoir was created. According to the results of the conducted studies, 24 fish species were identified in 2016, 21 in 2017, and 19 in 2020. Analysing the number of ichthyofauna since the 1960s, it can be concluded that every 10 years the species composition of the ichthyofauna of the Bilotserkivskyi lower reservoir lost about 2-3 species of fish, which is conditioned by the influence of riverbed overlap, industrial activities, uncontrolled and unidentified discharges into the reservoir, etc. After a detailed analysis of the number of ichthyofauna, it was established that by 2016, the following species had disappeared: common dace Leuciscus leuciscus, Dnieper chub P. borysthenicus, ide I. idus, sunbleak Leucaspius delineatus, vimba bream Vimba vimba, crucian carp Carassius carassius, weatherfish Misgurnus fossilis, spined loach Cobitis taenia; in 2017 – species such as gudgeon Gobio gobio, round goby Neogobius melanostomus, tubenose goby Proterorhinus marmoratus; in 2020 – char, ruffe. Quantitative and qualitative restoration of ichthyofauna is possible at the expense of fish from the Protoka River (Rotok). To continue fishing use, it is necessary to settle fish in the reservoir. The practical significance of this study is to determine the species composition of the ichthyofauna for further use of the reservoir for environmental and fishery purposes

Beaver-created microhabitats in a small water body and their impact on flora and fauna (the Khoper River floodplain, Russia)

This study shows how beaver digging activity can affect water body morphology and local biota under modern environmental conditions in a small floodplain lake. The total area of microhabitats created by beavers was found to reach 7% of water body area and 30% of littoral-zone area. It was noted that the zoogenic microhabitats are different when depth is greater and plant cover is smaller, especially of emergent vegetation. Helophytes Sparganium erectum and Alopecurus aequalis were found to prefer the beaver-unaffected part of the littoral. Invertebrates Naucoris sp. and Hydrophilus sp. prefer beaver microhabitats, whereas Planorbis planorbis, Lymnaea palustris, and Hydrous sp. prefer thickets of emergent plants in beaver-unaffected littoral areas. Adult crucian carps Carassius carassius proved to be abundant in the beaver-unaffected part of the water body, while the adult weatherfish Misgurnus fossilis prefers beaver burrows, and its fry inhabit beaver-unaffected sites. A similar situation was observed for marsh frogs Pelophylax ridibundus: adults prefer beaver microhabitats in June, but frog tadpoles mainly inhabit a beaver-unaffected littoral. Tadpoles of Pelobates vespertinus proved to be slightly aggregated near beaver burrows in July. The beaver activity was found to slightly increase β-diversity within the water body according to Jaccard indices. The results confirm that the beaver-created heterogeneity is important for aquatic biota under conditions of shallowing of floodplain water bodies.

A new fish-based index of biotic integrity for lowland rivers in Flanders (Belgium)—Corrigendum

This Corrigendum corrects an error in Table 2 that was published in Breine et al. (2021) on the pages 114–115: the line concerning the weatherfish Misgurnus fossilis (Linnaeus, 1758) on the page break was erroneously removed during publication and is added here.

First successful hybridization experiment between native European weatherfish (Misgurnus fossilis) and non-native Oriental weatherfish (M. anguillicaudatus) reveals no evidence for postzygotic barriers

The European weatherfish Misgurnus fossilis (Linnaeus, 1758) is a threatened freshwater species in large parts of Europe and might come under pressure from currently establishing exotic weatherfish species. Additional threats might arise if those species hybridize which has been questioned in previous research. Regarding the hybridization of M. fossilis × M. anguillicaudatus (Cantor, 1842), we demonstrate that despite the considerable genetic distance between parental species, the estimated long divergence time and different ploidy levels do not represent a postzygotic barrier for hybridization of the European and Oriental weatherfish. The paternal species can be easily differentiated based on external pigment patterns with hybrids showing intermediate patterns. No difference in standard metabolic rate, indicating a lack of hybrid vigour, renders predictions of potential threats to the European weatherfish from hybridization with the Oriental weatherfish difficult. Therefore, the genetic and physiological basis of invasiveness via hybridization remains elusive in Misgurnus species and requires further research. The existence of prezygotic reproductive isolation mechanisms and the fertility of F1 hybrids remains to be tested to predict the potential threats of globally invasive Oriental weatherfish species.

Sonography of the Heart of Weatherfish Misgurnus fossilis at the Prelarval Stage of Development

Sonography of the Heart of Weatherfish Misgurnus fossilis at the Prelarval Stage of Development

Food resource partitioning between juvenile and mature weatherfish Misgurnus fossilis.

This study represents a description of the diet composition of one of the largest European cobitids, the weatherfish Misgurnus fossilis. Specimens were collected in a drainage canal, representing a typical habitat for weatherfish, and with gut content analysis conducted with regard to individual total length and maturity stage. Overall, the weatherfish diet mainly consisted of Copepoda, Cladocera, Ostracoda, Oligochaeta, Asellus aquaticus, Chironomidae and Coleoptera larvae, Gastropoda, and detritus. To evaluate size‐related patterns of resource use, fish were assigned to two size classes, defined according to size at first maturation. ANOSIM analyses revealed major ontogenetic shifts in feeding strategy, which were related to size and maturity, with a significant ontogenetic shift in feeding pattern, marked by differences in the proportions of the main taxonomic groups of prey consumed. Copepoda and Cladocera dominated in the diet of small and immature individuals, while large weatherfish primarily fed on detritus. Similarly, cluster analysis of diet classified into these food types showed distinct two groups comprising juvenile and mature fish. The weatherfish is a food opportunist using all available resources, but spatially showed a change in feeding sites. Smaller and sexually immature individuals more often use prey caught in the water column and among macrophytes, while larger (sexually mature) individuals occupying the bottom, much more often use detritus as a food base.

The Influence of Fixatives on the Validity of Histological Preparations of Olfactory Organ in Teleostei

Abstract The olfactory system of fishes plays an important role in reproduction, migration, and feeding. When studying the morphogenesis of olfactory analyzer in fishes, it is crucial to determine the exact time at which the placode, olfactory pit, and olfactory lamellae are formed. Among a large number of fixatives, 10 % formalin and Bouin’s solution are most commonly used to study the olfactory organ of Teleostei. Use of inappropriate fixative or incorrect fixation process can damage the structures under investigation and, as a result, will lead to the misinterpretation of results. The influence of the fixatives on the preservation of olfactory structures of European weather fish Misgurnus fossilis (Linnaeus, 1758) as close as possible to their living state is studied. Similar stages were fixated in Bouin’s solution as well as in 10 % formalin. Histological preparations for the light microscopy were made using the standard histological methodologies. At all analyzed stages of European weather fish development, histological preparations are more accurate, reliable, and informative aft er the fixation in Bouin’s solution. Aft er the fixation in 10 % formalin, it is impossible to determine the moment at which the olfactory pit begins to form. Because of the artifacts of olfactory epithelium appearing aft er fixation in 10 % formalin, the timing of olfactory lamellae formation could be easily misinterpreted and a comparative analysis on the morphogenesis of the olfactory analyzer becomes more complicated. Given our observations, a thorough revision of previous literature has to be performed to derive accurate evolutionary and morphological interpretations.

FIRST RECORD OF THE WEATHERFISH MISGURNUS FOSSILIS (LINNAEUS, 1758) FROM THE ADRIATIC SEA CATCHMENT AREA IN BOSNIA AND HERZEGOVINA

This paper gives the first record of the weatherfish Misgurnus fossilis (Linnaeus, 1758) from the Adriatic Sea catchment area in Bosnia and Herzegovina.

Light Microscopy of Development of the Olfactory Organ of European Weatherfish Misgurnus fossilis (Тeleostei: Cobitidae).

We studied the formation of the olfactory organ of European weatherfish Misgurnus fossilis (Linnaeus, 1758) from the formation of its placodes to the formation of lamellae using light microscopy. The aim of the present investigation was to determine which morphogenetic features of the olfactory organ ate associated with the demersal lifestyle. The olfactory organ of European weatherfish goes through such developmental stages as olfactory placode, olfactory pit, and olfactory chamber with lamellae. Formation of the olfactory pit occurs in prolarvae, but a considerable increase in size takes place during the switch to exogenous feeding. In late larva, lamellae are formed in the aboral part olfactory chamber as an outward fold at its bottom. At the same time, incurrent and excurrent nostrils start being formed as the result of approximation of lateral and medial margins in the rostal part above the olfactory cavity. In contrast to other fishes, the peculiarity of morphogenesis of olfactory organ of M. fossilis is its late formation followed by intensive postembryonic development.

Thermal requirements for growth, survival and aerobic performance of weatherfish larvae Misgurnus fossilis.

Thermal requirements of larval weatherfish Misgurnus fossilis were investigated in terms of growth, survival and aerobic performance. Growth and survival of M. fossilis larvae acclimated to five temperatures (11, 15, 19, 23 and 27° C) were measured over 25 days. In the upper temperature treatments (19, 23 and 27° C), survival of larvae was stable throughout the entire rearing period (>75%), whereas 11 and 15° C resulted in severe declines in survival (to <10%). Growth of larvae (expressed as dry mass and total length) was highest at 19 and 23° C, but significantly decreased at 27° C. Routine metabolic rate of 3 days post-hatch larvae was estimated as oxygen consumption rate (ṀO2 ) during acute exposure (30 min to 1 h) to seven temperatures (11, 15, 19, 23, 27, 31 and 35° C). Larval oxygen uptake increased with each consecutive temperature step from 11 to 27° C, until a plateau was reached at temperatures >27° C. All larvae of the 35° C regime, however, died within the ṀO2 measurement period. M. fossilis larvae show greater than expected tolerance of high temperatures. On the other hand, low temperatures that are within the range of likely habitat conditions are critical because they might lead to high mortality rates when larvae are exposed over periods >10 days. These findings help to improve rearing conditions and to identify suitable waters for stocking and thus support the management of re-introduction activities for endangered M. fossilis.

Genetic species identification in weatherfish and first molecular confirmation of Oriental Weatherfish Misgurnus anguillicaudatus (Cantor, 1842) in Central Europe

The Oriental Weatherfish is considered a globally invasive fish species. In Europe, several reported feral populations of Oriental Weatherfish display an overlapping distribution range with native weatherfish Misgurnus fossilis , a declining species of international conservation and aquatic management concern. Morphologically distinguishing the different weatherfish species can be difficult, as their coloration is highly variable, many species reveal high phenotypic plasticity, and morphological traits like coloration might be not obvious or might be degraded during field sampling and after preservation. Herein, we analysed suspicious weatherfish specimens from southern Germany, demonstrating the usefulness of molecular genetic species identifications in this genus. We present the first molecular genetic species record of Misgurnus anguillicaudatus in Central Europe, and confirm the range expansion of Oriental Weatherfish into the river Inn catchment in southern Germany. As accurate species identification is crucial both in the context of monitoring and conserving native endangered species, and in early detection and prevention of biological invasion, we suggest the standard use of genetic species identification if morphological traits are not obvious.

Lactate dehydrogenase from the tetraploid weatherfish Misgurnus fossilis during temperature adaptation: Determination of structural differences in two forms of the enzyme by molecular modeling methods

A structural analysis of two lactate dehydrogenase M4 protein forms has been performed. These structures are the protein products of two lactate dehydrogenase gene (LDH-A) copies in the weatherfish Misgurnus fossilis genome after thermal adaptation (acclimation) to 5 degrees C and 18 degrees C. The localization of three earlier identified amino acid substitutions (Gly214Val, Leu304Ile, Asp312Glu) has been determined, and the molecular dynamics simulation and computer modeling of two forms of the enzyme from skeletal muscles LDH-M4 have been carried out. After molecular dynamics trajectory calculations carried out at 5, 18, and 25 degrees C, the intersubunit distances for all structures used in calculations have been determined. It has been found that the Gly214Val substitution localized in the intersubunit region leads to a new intersubunit interaction, which plays a role in the stabilization of tetrameric enzyme structure after the adaptation to 18 degrees C.

Out-of-season Spawning of Threatened Weatherfish Misgurnus Fossilis (L. 1758) Using Commercial Preparations Containing GnRH Analogues

Out-of-season Spawning of Threatened Weatherfish Misgurnus Fossilis (L. 1758) Using Commercial Preparations Containing GnRH Analogues

Sympatric occurrence of triploid, aneuploid and tetraploid weatherfish Misgurnus fossilis (Cypriniformes, Cobitidae)

Ploidy analyses of 116 weatherfish Misgurnus fossilis individuals revealed the sympatric occurrence of triploid, intermediate aneuploid and tetraploid specimens in a 1:1:4 ratio. No diploids were detected and the sex ratio of triploids and tetraploids was 1:1, while that of aneuploids was skewed at 3:1 for males. An origin of intermediate aneuploids from mating triploids with tetraploids is hypothesized.