Acta Biologica Ukrainica

The influence of the Eisenia fetida holding environment on medicinal leech breeding

2025-03-19T08:10:43+02:00

The study used 120 medicinal leeches, including 80 Hirudo verbana and 40 Hirudo orientalis. Four groups of animals were formed: two control and two experimental. The control groups consisted of medicinal leeches of both species, which were kept using the modern jar method. Experimental scheme. Control group: a peat-soil weakly acidic environment (pH 5.5) was prepared. As fertilization belts formed in leeches, they were transplanted into 3-litre sterile containers filled with the moist peat-soil medium. Afterwards, the containers were covered with a fabric that allowed for full oxygen permeability. The containers with the animals were placed in a dark room with a temperature of +25-26 °C and diffused artificial lighting. After a month, parent leeches and soft cocoons were collected. Juveniles were then selected from the cocoons and placed in sterile 3-litre containers filled with settled tap water. Experimental groups: instead of the peat-soil environment, medical leeches were placed in an environment selected from the Eisenia fetida (pH 5.0). All other manipulations were performed as in the control group. In the control group, animals in the peat-soil environment exhibited good health, with low mortality rates (Hirudo verbana 2.2±0.2% and Hirudo orientalis 1.9±0.2%) and high fecundity (Hirudo verbana 9.2±0.3% and Hirudo orientalis 6.1±0.2%), indicating the suitability of the maintenance environment p < 0.05. The experimental group yielded negative results, reflected in significantly higher mortality rates for both species: Hirudo verbana 75.2±4.2% and Hirudo orientalis 80±3.1%, p < 0.05). Furthermore, in the experimental groups, most animals produced few or no cocoons and offspring (Hirudo verbana 0.9±0.05%). A significant proportion of the cocoons were defective: Hirudo verbana 55.3±3.4% (p < 0.05). Fertile cocoons contained a limited number of offspring.

Prospects of using sweet clover Melilotus albus and sweet yellow clover Melilotus officinalis plants for recultivation of soils of Ukraine: review

2025-10-27T16:37:24+02:00

Recultivation of disturbed and polluted soils is one of the important tasks demanding solution in post-war future. The effectiveness of technologies of phytoremediation of soils under complex pollution of them will be limited by oil pollution, which is very toxic for plants. Selection of promising phytoremediation agents for recultivation of disturbed soils, polluted by heavy metals, oil and its derivatives is an important task nowadays. Herbaceous leguminous plants with highly developed root system can be promising phytoremediation agents for disturbed soils, polluted by heavy metals, oil and its derivatives. The paper presents analysis of contemporary literature sources concerning phytoremediation capabilities of sweet clover Melilotus albus and sweet yellow clover Melilotus officinalis plant species and the evaluation of their potential use in post-war reclamation of soils of Ukraine. It was shown that Melilotus species are the essential herbaceous leguminous plants for reclamation of salt-affected lands, soil fastening of inclines of ravines of various steepness. Melilotus plants fasten soil by their deep penetrating roots, which facilitate penetration of water, whereas their above-ground parts prevent soil erosion on the slope by rain water. It is worth noting that Melilotus species are resistant to soil pollution by heavy metals: Cr, Cu, Ni, Zn, Mo, Cd, Hg, Pb. M. officinalis acts as phytostabilizer. It accumulates heavy metals mostly in its roots, whereas further usage of its above-ground biomass is safe. It was shown that M. officinalis species is resistant against oil concentration 0,1‑5 % in soil and can collect specific soil microbial consortia in its rhizosphere which take part in oil decomposition. This explains its high recultivation potential – 8,8‑51,1% decrease of hydrocarbon content in soil. Phytoremediation potential of M. officinalis species is several times higher than M. albus species. M. albus and M. officinalis are cultivated in Ukraine. There are selection centers and production companies working with it. Therefore relatively inexpensive seed is available. As a summary of all the aforementioned information we consider Melilotus as promising species for the implementation of phytorecultivation technologies for the post-war reclamation of the affected soils.

Spatial characteristics of amphibian populations in the Lower Dnieper in the context of clarifying the south-eastern boundary of European ranges

2025-10-27T16:48:28+02:00

This work is review-based and contains a comprehensive summary of the spatial characteristics and status of local, peripheral populations of rare amphibian species in southern Ukraine in the Lower Dnieper basin (Kherson region). For the first time, a number of discrepancies between the actual and geographical distribution of individual species on the southeastern border of their European ranges are shown, which emphasizes the need for clarification and correction. The eight species studied occur in isolation, at a considerable distance from their main ranges, with the exception of Triturus dobrogicus, whose range is disjunctive and covers the basins of the Danube, Tisza, and Lower Dnieper. The latter population has been reliably confirmed but has not yet been included in the official range according to IUCN assessments. After the Kakhovka disaster, it suffered significant losses and was partially reintroduced, but due to military actions, its current status is unknown. This highlights the need for future official inclusion in the range and further research. Rare localities of Lissotriton vulgaris at the southern edge of the range demonstrate the peripheral and isolated distribution of the species, which provides important information for assessing its status and conservation in the region. The Bombina bombina population is characterized by fragmented distribution, which emphasizes the importance of critically reviewing the map of the European range and taking into account isolated pockets when assessing the distribution of the species. The spatial structure of the peripheral part of the Hyla orientalis range in Ukraine generally coincides with the outlined European range. It is assumed that Bufo bufo is threatened with extinction in the lower Dnieper region, as there is no current evidence of its presence. At the same time, this region is included in the map of the European range of the species, probably based on historical evidence. In the Lower Dnieper floodplain, Rana arvalis forms a stable, reliably confirmed small local population, which is included within the southeastern part of the European range of the species. As part of the rare REL system, Pelophylax lessonae forms an isolated population that is not reflected on the map of the European range, where the southern boundary of the species is marked much further north. The P. esculentus hybrid has more confirmed findings, but due to its uncertain species status, it is not included in international conservation lists, which makes it particularly vulnerable. Local amphibian populations are confined to rare forest-type floodplain habitats in the steppe zone of Ukraine and are in critical condition due to a combination of global threats and military action. A comprehensive analysis has shown that the isolated amphibian populations of the Lower Dnieper have unique conservation value, and their preservation requires the integration of military risks into conservation strategies, which creates the basis for the future ecological restoration of the region.