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.

Content of sialic acids, ATP and superoxide anion-radical in loach embryos under the influence of flurenizyd

It is known that flurenizide is a newly synthesized drug with pronounced antimicrobial, immunomodulatory functions. However, its effect on the functional properties of cells, in particular germ cells, is unknown. The aim of this study was to determine the presence of sialic acids as the final components of glycoconjugates, the main macroergic compound - ATP, to evaluate the generation of O2¯ in embryos of lobster (Misgurnus fossilis L.) under the influence of the antibiotic flurenizide. Studies have been performed on embryos of Misgurnus fossilis L. After fertilization, the zygotes were placed in Petri dishes with solutions of flurenizide in concentrations of 0.01; 0.05; 0.15; 1.0; 5.0; 15.0 mM, where allowed to develop. At the development stages, 2 blastomeres, 16 blastomeres, 64 blastomeres, VIII (256 blastomeres) and X divisions (1024 blastomeres) were sampled. In parallel, control studies were performed, where flureniside was not added to the samples. The content of sialic acids, ATP, superoxide anion radical was determined in the selected samples. We found that flureniside at the lowest concentration of 0.01 mM does not cause changes in the content of superoxide anion radical during early embryogenesis. The antibiotic in the maximum concentration causes changes in the content of free radical from the stage of development of 16 blastomeres to 1024 blastomeres, and from the stage of 64 blastomeres there is an increase in its number. Probably flurenizide at a concentration of 15.0 mM is the most reactive. It is known that flurenizide has antioxidant properties, but in its structure there are groups that have a toxic effect, which is most pronounced when exposed to high concentrations. In general, at the stage of development of 16 blastomeres there is a decrease in the amount of О2¯ under the influence of the studied antibiotic. At this time, the content of this free radical in the control increases, compared with other stages of development. Flureniside leads to an increase in the content of superoxide anion radical at development stage 2, 64 blastomeres and is particularly pronounced at concentrations from 0.05 to 15.0 mM at development stages 256 and 1024 blastomeres. 1024 blastomeres are the 10th stage of separation, where desynchronization occurs and the mitotic index decreases. Probably, the changes that take place at this stage of development are related to this. The antibiotic causes an increase in the content of sialic acids in the first stage of crushing (2 blastomeres). In step 16 of the blastomere, flureniside in low concentrations leads to a decrease in the content of sialic acids. However, already at the stage of separation of 64 and 256 blastomeres, the test substance in all concentrations causes a predominant decrease in the amount of sialic acids. At the last stage of synchronous crushing (1024 blastomeres) flurenizide in the maximum investigated concentration (15.0 mM) causes a significant accumulation of sialic acid content. Flureniside at concentrations of 0.15, 5.0 and 15.0 mМ causes a decrease in ATP content in loach embryos at the stage of development of 256 blastomeres by 28, 67 and 38 %, respectively. An increase in ATP content by 33 % occurs under the influence of flurenizide at a concentration of 1.0 mM. The ATP content also increases at the stage of development of embryos of 1024 blastomeres under the influence of flurenizide of all studied concentrations. Analysis of variance has shown that a significant contribution to the growth of ATP, sialic acid and superoxide anion radical, during the early embryogenesis of lobster embryos, is made by the factor of embryo development, while the factor of flureniside has a smaller contribution. Therefore, studies have shown that flurenizide causes increased generation of superoxide anion radical, decreased sialic acid content, as well as changes in ATP content in embryonic cells during early embryogenesis.

SPECIES COMPOSITION OF MACROPHYTES AND ICHTHYOFAUNA OF LAKE MARTYSHIV (KYIV, OSOKORKY) AS IMPORTANT ELEMENT OF THE INTACT FLOODPLAIN COMPLEXES

The article examines the species composition of macrophytes (higher aquatic plants) and ichthyofauna of Lake Martyshiv (waterbody of the Osokorky floodplain, eco-corridor of Kyiv). The features of the ecological distribution of higher aquatic plants within the lake Martyshiv are analyzed. The macrophytes are represented by typical limnophilous(lacustrine) complexes. The presence of various groups of macrophytes in the lake indicates a low level of anthropogenic load and is not so differentfrom the values characteristic of a surface water filesunder standard conditions. 22 species of higher aquatic plants have been registered. Phragmites australis (Cav.) Trin. ex Steud., Typha angustifolia L. and Typha latifolia Lare the most common swamping indicator species. Among the studied plants, it should be noted Nuphar lutea (L.) Smith which is protected on the territory of Kyiv in accordance with the decision of the Kyiv Council of December 23, 2004 No. 880/2290. In the ichthyofauna of Lake Martyshiv, 30 species of fish that belong to 9 familieswere identified. In the structure of ichthyocenosis, phytophils (50%) and zoobenthophages (50%) were the dominant ecological groups in terms ofthe method of oviposition and the type of nutrition, respectively. According to the habitat in the reservoir, bottomfishand thicket-livingcategories prevailed (43.3 and 33.3%, respectively). Four species were found in the ichthyofauna of the lake (Rhodeus amarus (Bloch, 1782), Cobitis taenia (sl) Linnaeus, 1758, Misgurnus fossilis (Linnaeus, 1758), Aspius aspius Linnaeus, 1758), which are included to the listof Resolution of the 6thBerne Conventionthat wasadopted to create the Emerald Network. In addition, Carassius carassius Linnaeus, 1758, listed in the Red Book of Ukraine, as well as the elmLeuciscus idus Linnaeus, 1758, which was included in the new edition of the Red Book of Ukraine, were discovered.The research results illustrate preliminary data on the current distribution of species and biological diversity of aquatic ecosystems of the Osokorkyfloodplain. The presence of a number of ecological groups of macrophytes creates a number of biotopes that are important for the existence and reproduction of fish. Thepreservation of LakeMartyshiv in a lesstransformed state providesgroundsforthe creation of a landscape reserve of local importance.Key words:Lake Martyshiv, macrophytes, ichthyofauna, biodiversity, environmental transformation, habitat. У статті розглянуто видовий склад макрофітів (вищі водяні рослини) та іхтіофауни оз. Мартишів (водойма Осокорківської заплави, екокоридору м. Києва). Проаналізовано особливості екологічного розподілу вищих водяних рослин у межах оз. Мартишів. Макрофіти представлені типовими лімнофільними (озерними) комплексами. Наявність різних груп макрофітів у межах озера вказує на низький рівень антропогенного навантаження та мало відрізняється від значень, характерних для масиву поверхневих вод у референційних умовах.Відзначено 22 види вищих водяних рослин. Найпоширеніші види-індикатори процесів заболочення: Phragmitesaustralis(Cav.)Trin. exSteud., Typha angustifolia L. та Typha latifolia L. Серед досліджуваних рослин варто виокремити глечики жовті Nuphar lutea(L.) Smith,які натериторії Києва охороняються на підставі рішенняКиївської міської ради від 23.12.2004 року No880/2290.У складі іхтіофауни оз. Мартишів виявлено 30 видів риб, які належали до 9 родин. У структурі іхтіоценозу за домінуючими екологічними групами за способомвідкладання ікри та типом живлення були фітофіли (50%) та зообентофаги (50%) відповідно. За середовищем існування у водоймі домінували риби придонних та заростевих груп (43,3 та 33,3% відповідно). В іхтіофауні озера було виявлено 4 види (Rhodeus amarus (Bloch, 1782), Cobitis taenia (s.l.) Linnaeus, 1758, Misgurnus fossilis (Linnaeus, 1758), AspiusaspiusLinnaeus, 1758.), які включені до списку Резолюції 6 Бернської конвенції, прийнятої для створення Смарагдової мережі. Крім того, був виявлений CarassiuscarassiusLinnaeus, 1758., що включений до Червоної книги України, а також в’язь Leuciscus idus Linnaeus, 1758, якого буде внесено до нового видання Червоної книги України.Результати досліджень ілюструють попередні дані щодо сучасного розподілу видів та біологічного різноманіття водних екосистем Осокорківської заплави. Наявність низки екологічних груп макрофітів створює низку оселищ, важливих для існування та розмноження риб. Збереження оз. Мартишів у мало трансформованому стані дає підстави для створення ландшафтного заказника.Ключові слова:озеро Мартишів, макрофіти, іхтіофауна, біорізноманіття, трансформація середовища, середовище існування.