Bioindicative characteristics of epilithic diatoms and ecological status assessment of selected rivers in western and central Serbia

Silikatne alge su opšte prihvaćene kao indikatori procene stanja i promena uslova u vodenim ekosistemima. Osobine koje ih čine odličnim indikatorima su mnogobrojne: globalna rasprostranjenost, naseljavanje različitih mikrostaništa, prisutnost tokom cele godine, kratko vreme generacije individualnih populacija, njihove dobro poznate ekološke valence, standardizovani načini uzorkovanja, pravljenja trajnih preparata i njihovog čuvanja, identifikacija do nivoa vrste i jasno definisan način procene brojnosti. Prvi program monitoringa ekološkog statusa površinskih voda u Republici Srbiji, koji je usklađen sa zahtevima Okvirne direktive o vodama (ODV) započet je 2012. godine. Cilj ove doktorske disertacije je utvrđivanje diverziteta i sezonske dinamike epilitskih zajednica silikatnih algi, formiranje preliminarne liste bioindikatora epilitskih silikatnih algi, predlog potencijalnih korekcija odgovarajućih dijatomnih indeksa za teritoriju Republike Srbije i procena ekološkog statusa odabranih reka zapadne i centralne Srbije. Istraživanjem su obuhvaćene tri reke u zapadnoj Srbiji (Rača, Raška i Studenica) i jedna u centralnoj Srbiji (Rasina). Sakupljanje uzoraka je obavljeno šest puta u toku 2011. i 2012. godine, sa šest lokaliteta u rekama Rači, Rasini i Studenici, odnosno sa pet lokaliteta u reci Raški. Podaci neophodni za izračunavanje indikatorskih vrednosti silikatnih algi su dobijeni iz Agencije za zaštitu životne sredine Republike Srbije. Tokom istraživanog perioda najveći broj taksona u epilitskoj zajednici silikatnih algi je identifikovan u Rasini (251), zatim u Studenici (190), Rači (171), dok je u Raški zabeležen najmanji broj taksona (122). Gomphonema, Navicula i Nitzschia su dominantni rodovi u odnosu na broj taksona u svim istraživanim rekama. Od ukupnog broja identifikovanih taksona 69 je po prvi put zabeleženo za teritoriju Srbije. Među njima, Geissleria gereckei, Navicula splendicula i Navicula moskalii su taksoni koji su retko nalaženi u Evropi...Diatoms are generally accepted as indicators for ecological status assessment and conditions change in aquatic ecosystems. Features that make them excellent indicators are numerous: worldwide distribution, colonization of different microhabitats, presence throughout the year, short generation time, known autecological characteristics, standardized sampling methods, making the permanent slides, their storage, identification to the level of the species and a clearly defined method of estimating the valve number. According to the Water Framework Directive (WFD), the first program for the monitoring of the ecological status of surface waters in the Republic of Serbia, started in 2012. The aim of this doctoral dissertation is determination of diversity and seasonal dynamics of epilithic diatoms, to form a preliminary list of epilithic diatom indicators, proposal of potential corrections of the appropriate diatom indices for the territory of the Republic of Serbia and ecological status assessment of selected rivers in Western and Central Serbia. The investigation includes three rivers in Western Serbia (Rača, Raška and Studenica) and one in Central Serbia (Rasina). Sampling was carried out six times during 2011 and 2012, on six sites in the rivers Rača, Rasina and Studenica and five in the Raška River. The data necessary for calculating diatom indicator values were obtained from the Serbian Environmental Protection Agency. During the investigated period, the highest number of taxa in the epilithic diatom community was recorded in the Rasina River (251), than in the Sudenica River (190), the Rača River (171), while the smallest number of taxa was recorded in the Raška River (122). The most abundant genera were Gomphonema, Navicula and Nitzschia. Of the total number of identified taxa 69 have been noted for the first time in Serbian diatom flora. Among them, Geissleria gereckei, Navicula splendicula and Navicula moskalii are taxa rarely found in Europe, too..

New taxon of the genus Navicula (Bacillariophyceae) for the diatom flora of Serbia

The main objective of this paper is to report benthic, epilithic diatom species from the Raška River. First time Husted described Navicula jakovljevicii in 1945. This taxon has been found outside the Balkan area for the first time, in the Lake Zug, Switzerland. Until now, there is no published data about diatom flora in Raška River. In the present study, we sampled benthic diatoms to evaluate the floristic richness of the river

New or rarely recorded diatoms taxa from Serbia (Dojkinačka stream, SE Serbia)

Diatoms (Bacillariophyta) inhabiting different types of substrate including stone surfaces, sand, mud, filamentous algae and submerged mosses in the Dojkinačka stream (SE Serbia) were studied by light microscopy. Among numerous common diatoms taxa we observed 17 rarely recorded taxa from Serbia and 5 new to the Serbian diatom flora (Brachysira intermedia (Øst.) Lange-Bert., Chamaepinnularia mediocris (Krass.) Lange-Bert., Navicula tridentula Krass., Eunotia paludosa Grun., Eunotia boreoalpina Lange-Bert. & Nörpel-Schem.). Among rare taxa, the most interesting was Diatomella balfouriana Grevill. In Serbia, it was known only from the River Tisa near Titel (Szabados 1966). In the material studied, it was identified only in samples collected from the surface of rocks at the third locality in unpolluted section of the Dojkinačka stream. We observed it in mass, together with Tetracyclus rupestris (Braun) Grun.11th Symposium of the Flora of Southeastern Serbia and Neighboring Regions, Vlasina, Serbia, 13.06.201

Morphological variation within the Placoneis elginensis (W.Gregory) E.J.Cox species complex

Freshwater diatom species Placoneis elginensis (W.Gregory) E.J.Cox was originally described in 1856 as Pinnularia elginensis W.Gregory. Because it is often confused with other species, its distribution requires closer investigation. The Placoneis elginensis species complex includes taxa with elliptic-lanceolate to linear-lanceolate valve shapes and capitate to rostrate apices. At present, six taxa are known from this complex: P. elginensis, P. paraelginensis Lange-Bertalot, P. abiskoensis (Hustedt) Lange-Bertalot & Metzeltin, P. ignorata (Schimanski) Lange-Bertalot, P. rostrata (A.Mayer) E.J.Cox and P. undulata (Østrup) Lange-Bertalot. Most of these taxa are widely distributed and rarely found in high numbers. They can occur in habitats with different environmental conditions, but mostly, they prefer mesotrophic to eutrophic waters with medium electrolyte content. During observations of different habitats (lakes, ponds, streams, wetlands, peat bogs) throughout North Macedonia seven species were recorded. In Taor cannel (near the city of Skopje), on mud, one new species from this complex was observed. It is characterized by elliptic-lanceolate valves with distinctly capitate apices, broad central area and distantly spaced striae (10–12 in 10 µm). All seven species are illustrated with LM and SEM and their morphological features are compared. Additionally, shape analyses of all species have been performed using software DiaOutline. For visualization and statistical evaluations, Principal Component Analyses (PCA), and Linear Discriminant Analyses (LDA) were used. Results showed that all analyzed species are significantly different with respect to the valve shape. Important separating features for the identification of species from this complex include valve shape, valve margin, shape of the valve apices and stria density.12th Central European Diatom meeting, Belvaux, Luxembourg, 26-27 March 201

Hidden dwellers on green frog’s skin (Pelophylax esculenta complex)

Recent research of frog skin microbiota were mainly focused on presence of pathogens, especially Batrachochytrium dendrobatidis, as well as on describing the bacterial communities on their skin. e specialized amphibian lifestyle where frogs’ skin is in intimate contact with the environment is of primary importance in determining frogs’ resilience to external factors. Cutaneous microbiota is thus an indicator of both frog health as well as of environmental factors acting upon frogs. Many of these factors can be detrimental to frog fitness and it is expected that the first changes in frog fitness could be assessed by identifying the changes in diversity patterns of frog’s skin epibiotic communities and/or isolating specific pathogens. Knowledge of these communities and patterns could contribute to more efficient conservation. Epibiotic communities of the green frog complex (Pelophylax esculenta complex), sampled on three localities in South Banat, Serbia (Stevanove Ravnice, Jaruga canal, DanubeTisaDanube Canal) were investigated using culture depended methods and microscopy techniques. Samples were collected using three sampling methods: 1) scraping by toothbrush for algal sample 2) swabbing with sterile cotton swabs for fungal sample and 3) nonaggressive adhesive tape method for both algal and fungal sample. e aim of this research was describing fungal and algal communities present on frogs’ skin. Culture based methods showed high diversity of airand soilborne fungi (members of genera Acremonium, Alternaria, Aspergillus, Bionectria, Bipolaris, Botrytis, Cladosporim, Epicoccum, Fusarium, Penicillium, Trichoderma, Ulocladium, to name a few), which could be considered transients. However, microscopy techniques revealed spore germination, mycelia formation and sporulation directly on frog skin, of some typical soilborne fungi eg. Fonseceae sp., causative agent of amphibian chromomycoses as well as human phaeohyphomycosis. Microscopy analyses of samples taken or scraped from amphibians’ skin showed the presence of morphological structures belonging to aeroaquatic hyphomycetes (eg. Canalisporium sp.) and stramenopiles, as well as high abundance of diatoms. Presence of c. 40 diatom genera was observed with dominance of mostly ubiquitous eurivalent species found in highly eutrophic waters (members of genera Amphora, Craticula, Cymbella, Cymbopleura, Cymatopleura, Diploneis, Encyonema, Epithemia, Fallacia, Gomphonema, Luticola, Navicula, Neidium, Nitzschia, Pinnularia, Planothidium, Rhopalodia, Staurosira and Surirella). Investigation of microbial communities on frog skin is of great importance due to potential detection of novel amphibian pathogens, and also can lead to better understanding of amphibianmicrobial interactions, which in further researches can be used as effective tool in amphibian protection.Explore and protect the natural beauty of Balkans. International Rufford Small Grants Conference. 27th – 28th September, 2018, Silver Lake, Serbia

Diatoms of the genus Gomphonema Ehrenberg fromthe peat bog at Pešter plateau

Diatoms are large and diverse group of single-celled algae and are distributed throughout the world in nearly all types of aquatic systems. The main purpose of this study was to collect records on the floristics and characteristics of the assemblages of the peat bog at Pešter plateau inhabiting diatoms. Peat bogs are very important as significant relict habitats and have unique character not only in Serbia but in Europe as well. One of the permanent componenets of the biota of peat bogs are diatoms. The material used in the present study was collected from peat bog at Pešter plateau in June and September 2008, May 2009 and August 2011 from three localities. Various types of diatom communities including epiphytes, benthos and plankton were studied. The results of a floristic analyses were focused on taxa representing the genus Gomphonema Ehrenberg. Taxa belonging to the genus Gomphonema were very frequently recorded diatom in the observed material. Among 250 records 22 belong to this genus. Some of them are widespread in Serbia, but five are new to the Serbian diatom flora. All reported taxa are documented by LM micrographs. Brief notes on their morphological characters and dimensions of frustule, distribution and ecology are provided.18th Symposium for Biology Students in Europe, Alexandroupoli, 23.07.2015

Desmid flora of fishpond Horgoš (Northern Serbia)

Fishpond Horgoš is situated in the north of Serbia, at the altitude of 75 m a.s.l, next to the Hungarian border. It was created due to long-term peat exploitation. There is no data about earlier algological research of fishpond Horgoš. The algological samples from fishpond Horgoš were collected in April, June, August and October 2008. All samples were fixed with formaldehyde to a final concentration of about 4% shortly after sampling. They were observed with a Carl Zeiss Axio Imager, M1 microscope and digital camera AxioCam MRc5 with AxioVision 4.8. software. The physicochemical analyses of water were performed at the Institute of Public Health of Serbia “Dr Milan Jovanović-Batut”, by standard analytical methods. The water temperature varies within the range of 13–22 °C, pH: 7–8; conductivity: 500–720 μS/cm; dissolved oxygen: 4.5–10.6 mg/l; BOD: 4.3–93 mg/l. On the basis the relevant literature (Lenzenweger 1996, 2003, Coesel & Meesters 2007) 28 desmid taxa were identified. Among 5 genera of desmids in all the most diverse was Closterium (18 taxa). During this research we identified 4 taxa from genera Cosmarium and Staurastrum, and 1-1 taxa from genera Staurodesmus and Teilingia. The species Closterium aciculare T. West, Cosmarium phaseolus Brébisson ex Ralfs and Staurastrum polymorphum Brébisson in Ralfs were the most quantitative abundant. The new species for Serbian desmids flora is Closterium nordstedtii Chodat. Fishpond Horgoš is characterized by desmid taxa, which prefer neutral to alkaline habitats. Results of statistical analysis using desmid as indicator showed that fishpond Horgoš is meso-eutrophic habitat.11th International Conference „Advances in research on the flora and vegetation of the Carpato-Pannonian region”, Budapest, 12–14 February 201

Prvi nalaz roda Haslea Simonsen u Srbiji i novi taksoni silikatnih algi za floru države u ekstremnim i jedinstvenim staništima Vojvodine

Salt habitats are extreme and unique environments found from Austria through Hungary to the Vojvodina Province in Serbia. In our study, we investigated eight saline habitats (channeled salt marshes, moist salt meadows and saline ponds), from which we collectedplankton, epipelic and epiphytic diatoms. Seventeen diatom taxa new for the Serbian diatom flora were recorded. In addition, the genus Haslea, with one species (H. spicula), was recorded for the first time in Serbia. The identified taxa were sporadic or rare in the samples.Alkalna slana jezera, bare i močvare su ekstremna i jedinstvena staništa rasprostranjena u Austriji, Mađarskoj i Srbiji (Vojvodina). Istraživanje je obuhvatilo osam slanih staništa različitog tipa: kanalizovane slatine, zabarena slana staništa i slane bare. Uzorci obuhvataju različite zajednice silikatnih algi: plankton, bentos i epifite. Utvrđeno je prisustvo 17 taksona silikatnih algi po prvi put zabeleženih na teritoriji Srbije, a među njima prvi put i rod Haslea Simonsen sa jednom vrstom, H. spicula. Identifikovani taksoni su retki i sporadično nalaženi u uzorcima

BIODIVERSITY OVERVIEW OF SODA PANS IN THE VOJVODINA REGION (SERBIA)

Due to their specific physical and chemical properties of water and soil soda pans of the Vojvodina region represent a unique type of habitats. Salinity is a major structuring factor which strongly affects species richness. Many halotolerant, alkalotolerant and halophilic organisms, together with numerous eurytopic elements inhabit these kinds of ecosystems. In this review we tried to compile the biodiversity information from various literature sources and give the best representation of what can be expected to be found in these shallow, temporary and intermittent aquatic environments. Only a few groups of organisms are fairly well studied, while many others are insufficiently investigated or the knowledge of them is lacking altogether. Best investigated are certain groups of algae and birds. Bacterial communities, as well as many invertebrate groups, are poorly studied or not investigated at all. Characteristic elements of flora and fauna, together with growing anthropogenic pressures make soda pans prime targets for protection

Prilog poznavanju distribucije roda Navicula na teritoriji Srbije

Rod Navicula 1822. godine je opisao Bory de St. Vincent obuhvativši birafidne izopolarne taksone vretenastog oblika. Vrste roda Navicula karakterišu poprečne pruge izgrađene od jednog niza pora (lineola), filiformna rafa i dva krupna hromatofora. Prema podacima iz Algaebase (Guiry i Guiry 2018) rod Navicula obuhvata 1264 taksona. Tokom 2011. i 2012. godine sakupljeni su epilitski uzorci silikatnih algi iz sedam reka Srbije (Rasina, Rača, Raška, Studenica, Mlava, Vrla i Radovanska reka). Rezultati su pokazali da je rod Navicula jedan od najzastupljenijih u istraživanim rekama. Od ukupnog broja identifikovanih taksona zabeleženo je 15 novih za floru silikatnih algi Srbije. Svi ovi taksoni preferiraju karbonatne, oligo- do eutrofne vode, sa pH većom od 7 i umerenom koncentracijom elektrolita. Nijedan od ovih taksona nije zabeležen sa značajnom brojnošću, ali je njihovo prisustvo važano sa aspekta biodiverziteta. N. moskalii se izdvaja kao retko zabeležen takson u Evropi (Cantontati i sar. 2017). Rezultati naših istraživanja šire njen areal, kao i opseg dimenzija valve, pružajući nove detalje o autekološkim karakteristikama taksona. Ovi rezultati ukazuju na neophodnost detaljnijih i intenzivnijih istraživanja u cilju proširenja znanja o silikatnim algama Srbije.Kladovo, Srbija, 25–30.09.2018. [www.serbiosoc.org.rs