The Journal of V.N.Karazin Kharkiv National University. Series «Biology»

Breeding bird communities of the pine forests in the forest-steppe zone

2024-08-29T14:19:24+00:00

The avifauna of pine forests in the North-East of Ukraine has been poorly studied. Analysis of bird communities showed that the avifaunal complexes of pine forests are poorer and have minimal similarity to those in deciduous forests. This study aimed to assess the species composition and densities of birds in the pine forest of various ages. Research was conducted on the National Park «Slobozhanskiy», located within the Krasnokutsk United Territorial Community of the Bogodukhiv District in the northwestern part of Kharkiv Region (Ukraine). Most of the park's forests are of artificial origin. Birds communities were studied in May 2023 in six forest types: pine forest less than 25 years old, pine forest 71-90 years old, pine forest 91-110 years old, pine forest over 110 years old, patches of oak stands and patches of birch stands. The point-count technique was used for bird sampling. Overall 60 point-count stations (10 in each forest type) were located using a forest map. The breeding avifauna was classified concerning nest location, according to the sites for searching food, and based upon migration patterns. We registered 39 breeding bird species during point counts; of them 3 were cavity excavators, 13 were secondary cavity users, 13 were tree and 3 were shrub foliage nesters and 6 were ground nesters. There were 7 trunk-foraging species, 15 canopy-foraging species, 3 shrub-foraging species, and 12 ground-foraging species. Eighteen species were long-distance migrants, 6 species were short-distance migrants, and 15 species were residents. The least number of species (16) was recorded in pine forests less than 25 years old. The number of species in other forest types varies slightly (23-25). The lowest total abundance was noted in pine forests less than 25 years old, and the highest in patches of oak stands. Total density differs between all types of forest, except for a couple of pine forests 91-110 years old – patches of birch stands. In pine forest less than 25 years old dominate European Robin (45.1%) and Common Chiffchaff (25.3%); in pine forest 71-90 years old – Wood Warbler (28.3%) and Common Chaffinch (20.4%); in pine forest 91-110 years old – Common Chaffinch (16.4%), Wood Warbler (12.9%), Collared Flycatcher (12.0%), and European Robin (10.9%); in pine forest over 110 years old – Common Chaffinch (18.7%), European Robin (15.0%), Great Tit (12.8%) and Collared Flycatcher (11.9%); in patches of oak stands – Collared Flycatcher (20.1%), Great Tit (19.3%) and Common Chaffinch (14.3%); and in patches of birch stands – Wood Warbler (20.6%), Collared Flycatcher (16.7%), European Robin (14.9%) and Common Chaffinch (13.3%). The most abundant birds in pine forests less than 25 years old were ground nesters (70.5%). In other age groups of the pine forest and the patches of birch stands, secondary cavity users and ground nesters co-dominated. In patches of oak stands secondary cavity users dominated (50.8%). In all types of forests, except for the pine forest less than 25 years old canopy gleaners dominated. Large-distance migrants were the most abundant birds in pine forests. except the pine forest less than 25 years old. and patches of birch stands. In the pine forests less than 25 years old short-distance migrants dominated (56.5%). Residents dominated in patches of oak stands (39.7%). We compared our results with those of other studies conducted in the region's pine forests since the mid-19th century.

Molecular mechanisms and therapeutic strategies of Naegleria fowleri Carter (1970): a review of the fatal brain-eating amoeba

2024-08-29T14:20:00+00:00

Naegleria fowleri is a thermophilic free-living amoeba that can cause a rare and fatal infection of the brain called primary amoebic meningoencephalitis (PAM). PAM is a serious public health concern, as it affects mostly young and healthy individuals who are exposed to warm freshwater environments, and has a mortality rate of approximately 98%. The infection occurs when the amoeba enters the nasal cavity during swimming or other recreational activities, and migrates to the brain through the olfactory nerve. In the brain, the amoeba causes extensive tissue necrosis, haemorrhage, and inflammation, leading to severe neurological symptoms and death within days. The pathogenesis of N. fowleri infection is not fully elucidated, but recent studies have shed some light on the molecular mechanisms that enable the amoeba to invade, proliferate, and evade the host immune system. These mechanisms include the expression of various surface molecules that mediate adhesion, motility, and phagocytosis of host cells, as well as the secretion of proteases and other factors that degrade host extracellular matrix and modulate host immune response. However, there are still many unanswered questions regarding the complex interactions between the amoeba and its host, which limit the development of effective diagnostic and therapeutic strategies. PAM is often misdiagnosed as bacterial meningitis, due to its nonspecific clinical presentation and lack of reliable diagnostic tests. This results in delayed or inappropriate treatment and poor prognosis. Currently, there is no specific or approved treatment for PAM, and the available options are based on empirical evidence or case reports. The survival rate of PAM remains very low, despite the use of multiple drugs and supportive care. Therefore, there is an urgent need for more research on the pathogenesis of N. fowleri and the identification of novel targets for intervention. With the advances in genomic and proteomic technologies, new opportunities have emerged to explore the molecular biology of N. fowleri and its host response. By identifying the genes and proteins involved in key processes such as adhesion, motility, and immune evasion, researchers can design targeted therapies to disrupt these essential functions and prevent or treat infection. This review provides a comprehensive overview of the current state of knowledge on N. fowleri, its pathogenic molecular mechanisms, and the biological processes involved in its infection, as well as the challenges and perspectives for future research.

An updated checklist of spiders (Arachnida, Araneae) of the protected areas of the Kherson region (Ukraine)

2024-09-18T11:47:03+00:00

The protected areas of Kherson region include 84 sites of different categories, of which only one-tenth been studied in terms of spider diversity. It is advisable to use the results of long-term monitoring of flora and fauna to assess the level of conservation of protected areas, including species composition, abundance, and character of spider communities, Accordinly, a list of spider species of nine objects of the Nature Reserve Fund of Ukraine has beed compiled It includes two bdiosphere reserves, five national nature parks, and two preserves. The literature data were supplemented with the results of my research in 2021 on the territories of the Dzharylhatskyi and Oleshkivski Pisky Nature Parks. The spider fauna of the protected areas of the Kherson region includes 363 species of 30 families. Ten species Cyclosa sierrae Simon, 1870, Eresus moravicus Řezáč, 2008, Nomisia exornata (C.L. Koch, 1839), Oxyopes globifer Simon, 1876, Pirata piscatorius (Clerck, 1757), Singa semiatra L. Koch, 1867, Trochosa hispanica Simon, 1870, Zelotes tenuis (L. Koch, 1866), Erigonoplus jarmilae (Miller, 1943), Titanoeca spominima (Taczanowski, 1866) were recorded for the first time from the Kherson region. The latter two were added to the list after reviewing the collection of spiders from the Chornomorskiy Biosphere Reserve. For the first time in Ukraine, Neaetha absheronica Logunov & Guseinov, 2002 (1 male; June ‒ July 2021; 46.025905N, 32.934212E) was found in a psammophytic steppe of a wide part of the Dzharylgach Spit ('Dzharylhatskyi' NNP), which extends the northern border of the species' range. The genus Neaetha (Salticidae) is also new to Ukraine. The records of Eresus kollari Rossi, 1846, Civizelotes pygmaeus (Miller, 1943) and Minicia marginella (Wider, 1834) need to be confirmed. According to the author's estimates, the spider fauna of the Kherson region includes approximately 400 species. Among the upcoming research, it is planned to make an inventory of the spider fauna and analyze their communities to assess the impact of hostilities, as well as to update the information on the spider species diversity of the Chornomorskiy and Askania Nova Biosphere Reserves. A comprehensive sozological assessment of the areas proposed for protection, which already have detailed botanical descriptions, is expected. There is a high probability of extinction of a number of species from the above mentioned protected areas, since all the studied sites were affected by the hostilities.

On the seasonal dynamics of groups of short-winged beetles (Staphylinidae, Coleoptera, Insecta) in the forest ecosystems of the Gorgan mountain massif

2024-10-04T14:25:27+00:00

У роботі висвітлюються особливості сезонної активності імаго стафілінід, що трапляються у різних типах лісових екосистем гірського масиву Ґорґан. Територія досліджень охопила три ландшафтно-висотні пояси у межах яких виокремлюються п’ять типів лісових екосистем: криволісся сосни гірської та ліси сосни кедрової європейської (субальпійський пояс), смереково-ялицеві ліси (верхній лісовий пояс), а також мішані (смереково-ялицево-букові) і букові ліси (нижній лісовий пояс). Збір колекційного матеріалу проводився у 2017–2021 роках впродовж всього вегетаційного періоду з використанням пасток Барбера. За час проведення досліджень виявлено представників 76 видів стафілінід, що належать до 13 підродин. Найвищим рівнем видового багатства характеризуються підродини Staphylininae, Tachyporinae, Steninae. Найбільше число видів було зареєстровано у букових лісах (55 видів), а найменше ‒ у лісах сосни гірської (23 види) та сосни кедрової європейської (25 видів). У кожній екосистемі траплялися специфічні види, лише п’ять видів були спільними для всіх аналізованих біоценозів: Atrecus longiceps, Philonthus decorus, Tasqius morsitans compressus, Stenus comma comma, Tachynus rufipes.

Аналіз сезонної динаміки коротконадкрилих жуків продемонстрував спільні риси для угруповань у різних типах лісових екосистем. Зокрема, найвищі показники активності комах спостерігаються упродовж червня-липня, а найнижчі – у квітні та жовтні. Винятком є екосистеми сосни гірської та сосни кедрової європейської, у яких Staphylinidae трапляються з другої половини травня до кінця серпня, а окремі види ‒ у першій половині вересня. Упродовж теплого періоду року в угрупованнях стафілінід спостерігають від два-три піки активності.

У криволіссі сосни гірської літній пік припадає на другу декаду липня, домінують три види ‒ Eusphalerum primulare, Omalium rugatum i Tasgius morsitans compressus. Осіннє зростання активності характеризується набагато меншим ступенем вираженості та домінуванням Paederus (Poedemorphus) littoralis littoralis та Tachyporus hypnorum.

У біогеценозі сосни кедрової європейської угруповання коротконадкрилих жуків формують два літніх піки: перший впродовж І декади липня та другий у ІІ декаді серпня. Впродовж липневого піку домінують Omalium rugatum, Eusphalerum primulare й Oxyporus rufus rufus, а серпневого – Acidota crenata, Atrecus longiceps і Lordithon trinotatus.

В угрупованні стафілінід смереково-ялицевих лісів перший пік активності формується влітку, а другий – восени, які розмежовуються між собою відносно рівномірним зниженням активності. Домінантними відповідно є Eusphalerum primulare, Ocypus (Matidus) nitens nitens, Staphylinus caesereus caesereus, та Tasgius (Rayachelia) morsitans compressus, Lordithon lunulatus.

Угруповання стафілінід у мішаних лісах формують два піки активності: весняний та літній. Впродовж першого піку найчастіше трапляються Ontholestes tesselatus, Tachyporus chrysomelinus, Anotylus sculptoratus, Philonthus decorus; другого ‒ Tasgius melanarius, Tachyporus chrysomelinus, Philonthus splendens, Philonthus rubripennis. Для угруповань стафілінід у букових лісах також притаманні два яскраво виражені піки активності. Впродовж яких переважають Tasgius bicharicus, Staphylinus caesereus, Staphylnus erythropterus, Tasgius bicharicus, Nudobius lеnthus, Lordithon trinotatus та Abemus chloropterus, Tachyporus chrysomelinus та Lordithon lunupatus.

Ecological analysis of the fish trematode fauna of the Lower Kura

2024-08-29T14:22:07+00:00

In 2007-2022, in three sections of the lower reaches of the Kura River, 933 cyclostomes and fish belonging to 38 species were subjected to complete parasitological dissections, and 40 species of trematodes were discovered. Of these, 25 species complete their development in fish, and 15 species in fish-eating birds. 24 species parasitize in the fish intestines, 5 species in the lenses of fish eyes, and 1-2 species of trematodes are localized in other organs. Most of the discovered species of trematodes are freshwater forms; typically marine are only 4 species, which were found in marine fish that come here from the Caspian Sea. The examined fish belong to five trophic groups: ichthyophages, benthophages, planktophages, phytophages and detritiphages. In the ichthyophages were dominated by trematodes, which complete their development in fish. Apparently, these parasites enter the body of ichthyophages for the most part by eating fish infected by them. In the remaining trophic groups, the fauna of trematodes was significantly dominated by species parasitizing fish at the metacercaria stage. In the lower section of the Lower Kura, 37 species were found, of which 12 complete their development in fish-eating birds. This comparative richness of trematode fauna of lower section is due to the fact that it contains many more species of fish than other sites; the current speed is much lower and this promotes the development of mollusks - the first intermediate hosts of trematodes; there are a large number of fish-eating birds - the definitive hosts of many species of fish trematodes; the current carries here infected intermediate hosts and trematode cercariae from more upper sections; only here marine fish species were examined and marine trematodes were discovered; only here the lamprey was studied and one of its characteristic trematodes was faund. In the fish of the middle section, 26 species of trematodes were noted, of which 13 species complete development in fish-eating birds. Here the fauna of fish trematodes is somewhat poorer than in the lower section, but here there are more species of trematodes whose cercariae actively penetrate fish. This is due to the fact that not far from the point of collecting the material, Lake Sarysu is located, where a large number of fish-eating birds live. In fish living in the upper section, 22 species of trematodes were found, of which 10 species complete their development in fish-eating birds. Among all the noted trematodes, 7 species are pathogens of fish diseases and 1 species is dangerous to human.