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

Ecological status of the Raška River evaluated by epiphytic diatom community

Bentosne silikatne alge koriste se kao bioindikatori i smatraju se korisnim u proceni ekološkog statusa voda. Uzorci epifitske zajednice silikatnih algi reke Raške sakupljeni su tokom pet sezona (2011. i 2012. godine), sa po 5 lokaliteta. Cilj ovog rada je određivanje vrednosti 17 dijatomnih indeksa radi procene ekološkog statusa vode reke Raške. Dobijene vrednosti dijatomnih indeksa ukazuju da je ekološki status vode reke Raške dobar do veoma dobar, sa umerenom do povišenom koncentracijom nutrijenata, beza većih varijacija u vrednostima između lokaliteta.Benthic diatoms have been regularly used as ecological indicators and considered to be valuable in water quality assessment and monitoring. Epiphytic samples were collected from five points during five seasons (2011-2012). The objective of this paper is to evaluate applicability of 17 diatom based indices used worldwide for water quality assessment. The water of the Raška River can be characterized as good to very good quality with moderate to elevated concentration of nutrients

Epiphytic and epilithic diatom communities along the Raška River – implications for the water quality

We compared epiphytic and epilithic diatom communities in the Raška River, and their use in river biomonitoring. The material was collected in April, June, August and November 2011, and March 2012 from 5 localities along the Raška River. The result showed high variation of the diatom species composition between this two micro-habitats. The most abundant genera were Navicula, Gomphonema and Nitzschia, but with higher diversity in epiphytic diatom community. During first season, Achnanthidium minutissimum and Gomphonema tergestinum were dominant taxa in epilithic, while A. minutissimum and Diatoma vulgaris in epiphytic diatom community. Epilithic diatoms are the favoured community for monitoring water quality. However, at any river, diatom species are located on various substrates at the same sampling site. For diatom diversity assessment it is necessary to investigate all micro-habitats. Our results point to a difference in values of TDI diatom index between macrophytes and stone samples. Is it necessary to investigate all micro-habitats, or is the type of substratum independent for water quality monitoring?6th Balkan Botanical Congress, Rijeka, September 14-18, 201

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

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

Epiphytic diatoms from genus Navicula (Suvi Do, Pešte plateau, Serbia)

Rad sadrži podatke o sastavu epifitskih silikatnih algi roda Navicula (sensu stricto i sensu lato) sa lokaliteta Suvi Do (Pešterska visoravan, Srbija). Uzorci su sakupljani u julu i septembru 2008. godine i u maju 2009. godine ceđenjem mahovina Calliergon giganteum [(Schimp.) Kindb.], kao i struganjem epifita sa površine mahovina. U laboratoriji algološki uzorci su tretirani standardnom metodom sa koncentrovanom sumpornom kiselinom i kalijum permanganatom, a potom su napravljeni trajni preparati silikatnih algi. Pregledom preparata identifikovano je 14 taksona epifitskih silikatnih algi roda Navicula. U okviru roda Navicula sensu stricto identifikovano je 8 taksona. Analize su pokazale i prisustvo taksona iz rodova Placoneis, Cavinula i Sellaphora (rodovi u okviru Navicula sensu lato). Ovo su prvi podaci o rasprostranjenju silikatnih algi na Pešterskoj visoravni. Rezultati ovog rada uključuju i 4 nova taksona za floru silikatnih algi Srbije.The paper includes data for the composition of epiphytic diatoms of the genus Navicula (sensu stricto and sensu lato) from the site Suvi Do (Pester plateau, Serbian). Samples were collected in July and September 2008. year and in May 2009. squeezing the moss Calliergon giganteum [(Schimp.) Kindb.], and epiphytes by scraping the surface of moss. In the laboratory, samples were treated in standard method with concentrated sulfuric acid and potassium permanganate, and then were made permanent preparations of diatoms. A review of preparations identified 14 taxa of epiphytic diatoms genus Navicula. Within the genus Navicula sensu stricto 8 taxa were identified. Analysis showed the presence of taxa of the genera Placoneis, Cavinula and Sellaphora (in the genera Navicula sensu lato). These are the first data on the distribution of diatoms in the Pester plateau. The results of this study include 4 new taxa for diatoms flora of Serbia.Perućac, Serbia, 04-06.06.201

Interesting Navicula Bory de Saint-Vincent species from Serbia

The genus Navicula was originally described in 1822 by Bory de St. Vincent. The concept of Navicula has changed from extremely heterogeneous collective genus to a narrowly defined, apparently homogeneous genus. The group Navicula sensu stricto involves 250-300 species and the great majority of them live in fresh, inland waters, and few inhabit brackish waters (Lange-Bertalot 2001). Knowledge about diatom biodiversity increase as a result of a more detail morphometric analysis of the frustula by light (LM) and scanning electron microscopy (SEM). Navicula splendicula was described by Van Landingham (1975). According to Lange-Bertalot (2001) it is known to inhabit southern and central Europe, with certainty. Distribution of N. splendicula from 2001 till today become wider, but in published papers SEM micrographs, as well as the dimensions of frustula, were not given and specified. LM and SEM observation of species from Serbia (Rasina and Vrla rivers) showed a variation from literature data regarding dimensions of frustula and variability of the ultrastructure of the central raphe ends. The poster illustrates all differentiating characters with brief notes on the ecology of the N. splendicula from two rivers in Serbia.10th Central European Diatom Meeting (10th CEDM), 20 – 23 April, 2016, Budapes

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

Rod Haslea i novi taksoni silikatnih algi za floru Srbije u alkalnim slanim staništima Vojvodine

Alkalna slana staništa predstavljaju jedinstvena staništa koja su specifična za centralnu Evropu i nalaze se na listi prioritetnih staništa Evropske Direktive o staništima (Directive Habitats 1992). Ono što ova staništa izdvaja od drugih sličnih slanih voda je dominacija jona Na+, HCO3– and CO32–. U Srbiji ona su retka, ugrožena, mozaično raspoređena i najzastupljenija na teritoriji Vojvodine. Povišen salinitet i promenljiv vodni režim tokom godine su glavni faktori koji uslovljavaju pojavu jedinstvenog biljnog i životinjskog sveta. Algološki uzorci su sakupljani u periodu od 2003. godine do danas. Istraživanje je obuhvatilo 10 lokaliteta, koji predstavljaju različite tipove alkalnih slanih staništa: kanalizovane slatine, zabarene slane livade, slane bare i mineralne bare. Uzorci obuhvataju različite zajednice silikatnih algi: plankton, bentos i epifite. Utvrđeno je prisustvo 22 taksona silikatnih algi po prvi put zabeleženih na teritoriji Srbije, a među njima prvi put i rod Haslea Simonsen sa dve vrste: H. duerrenbergiana i H. spicula. Identifikovani taksoni su karakteristični za brakične vode, kao i različite tipove kopnenih voda sa povišenim do veoma povišenim sadržajem elektrolita. Dosadašnja istraživanja silikatnih algi alkalnih slanih staništa Vojvodine su sporadična (Vidaković i sar. 2018). Ovakav tip istraživanja je neophodan kako bi što bolje sagledali diverzitet silikatnih algi u cilju očuvanja ovih jedinstvenih staništa koja su pod intezivnim i konstantnim antropogenim uticajem.Kladovo, Srbija, 25–30.09.2018. [www.serbiosoc.org.rs