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Rad govori o kirurškom pristupu karcinomu dojke u ranom stadiju bolesti.

This research provides a description of the epiphytic diatom community living on the blades of the marine seagrass Posidonia oceanica in the coastal area of the eastern Adriatic Sea. Samples were collected in May 2017, from a meadow located in Tetevišćica Bay, on the western side of Dugi otok island (43° 58’ 22’’ N; 15° 03’ 36’’ E) at three depths: 10, 15 and 20 m. Each blade sample was divided into three segments along the leaf axis (basal meristemal, middle and apical) to explore the possible community zonation pattern. Twenty-one samples were analyzed by light microscope and the epiphytic diatom community structure was determined. A total of 68 taxa belonging to 30 genera were found: 43 from 10 m depth, 41 from 15 m depth and 39 from 20 m depth. All identified species are commonly recorded from other marine benthic periphytic and epiphytic habitats. The genus Cocconeis was dominant in all samples, which is typical for epiphytic biofouling of P. oceanica leaves. Although no changes in the community structure related to the position on P. oceanica blade were observed, ANOSIM tests (p, U ovom je radu istraživan epifitski obraštaj algi kremenjašica (dijatomeja) na listovima morske cvjetnice Posidonia oceanica u obalnom području istočnog Jadrana. Uzorci su sakupljeni u svibnju 2017, s livade morske cvjetnice u uvali Tetevišćica (43° 58’ 22’’ N; 15° 03’ 36’’ E) koja se nalazi na zapadnoj obali Dugog Otoka s ukupno tri dubine: 10, 15 i 20 m. Svaki uzorak lista podijeljen je duž lisne osi na tri dijela: bazalni, srednji te apikalni dio. Analiziran je 21 uzorak pomoću svjetlosnog mikroskopa te određena struktura epifitskih dijatomejskih zajednica. Identificirano je ukupno 68 svojti podijeljenih u 30 rodova, 43 svojte s dubine 10 m, 41 s dubine 15 m i 39 s dubine 20 m. Sve zabilježene svojte su tipične za morska bentička, perifitonska i epifitska staništa. Rod Cocconeis bio je dominantan u zajednicama na svim dubinama, što je i karakteristika epifitskih obraštaja na listovima P. oceanica. Unatoč tome što nije zabilježena razlika u zajednicama dijatomeja s obzirom na položaj na listu, ANOSIM test (p

Loggerhead turtles (Caretta caretta) are primarily open-ocean animals that visit shallow coastal areas only for nesting. The geographic distribution and behavior of the species are strongly related to water temperature, food availability and oceanic currents. The turtle carapaces include a surface biofilm that serves as a habitat for epibiontic microorganisms such as bacteria and unicellular protists with diatoms being prominent in the assemblage. Research on diatom commensals on loggerhead turtle carapaces can provide interesting information on environments visited and general migration routes of the turtles. Mucilage stalks of the diatoms enable attachment to the carapace, but diatoms may also live inside mucilaginous tubes e.g. Parlibellus sp., or embed cells in mucilage matrix developed on the carapace surface. However, numerous diatoms simply inhabit the microbial EPS (extracellular polymeric substance) mixed with the mineral particles and form a distinct biofilm over the carapace. Here presented are results of a research on biofilm collected from Dalyan Beach region in Aegean Sea coast of SW Turkey during 2014 – 2018. The Dalyan Beach is considered one of the important Mediterranean nesting grounds for C. caretta. In 2016, a few pilot samples have been collected from C. caretta carapaces from Adriatic Sea (Croatia), the migration route for this species. Numerous diatoms, principally small pennate species, were isolated from biofilm into culture principally belonging in Navicula, Nitzschia, Diploneis, Halamphora, Entomoneis, Amphora and one centric Melosira sp. The true epibionts isolated in culture were few and involved stalked Achnanthes spp. and tube-dwelling Parlibellus spp. Identification of diatoms has principally been based on LM and SEM analyses of cleaned material. Diatoms in clonal cultures isolated from the C. caretta biofilm provided DNA that has been sequenced. A combined morphology (LM, SEM) and molecular markers (SSU, psbC, rbcL) establish a data base on a few dozens of taxa living in the C. caretta carapace biofilm. The spatial and temporal (sampling year) diversity of the diatom assemblages have been tested with multivariate analysis and multimetric ordination analysis (nonparametric multidimensional scaling – MDS).

Dynamics of a diatom community was studied during winter-spring period in span of two years that differed with respect to the oceanographic conditions induced by specific hydroclimatic events in southern Adriatic. Sampling station was situated in the South Adriatic Pit (SAP) with depth of 1200 m. Altogether, 16 research cruises were undertaken and in total 232 bottle samples were observed for physical-chemical and phytoplankton analizes. Two specific phenomena were recorded in SAP during investigated periods: high abundances of diatoms in the aphotic zone associated with strong downward flow, and intense surface diatom bloom in 2017 induced by strong vertical convective mixing which increase nutrient availability in surface layer. Diatoms were the most diverse and abundant group of microphytoplankton (MICRO) during investigated periods, classified into 102 taxa of 48 genera. Contribution of diatoms in MICRO abundance ranged from 8.3 to 97.9% in 2016 and from 0.4 to 99.6% in 2017 with intense development and contribution during bloom in March 2017. At that time (3th and 20th of March) diatom abundances ranged from 6.1x102 to 5x104 cells L-1 and 2x102 to 1.9 x105 cells L- 1, respectively. In the begining of bloom (3th of March), intensive development of diatoms was recorded in surface layer (0-50 m). During the peak (20th of March) high abundances spread to 300 m. Four days later (24th of March), diatom abundance decreased in the surface layer and maintained in the reduced values in the deep samples (under 75 m). The diatom community during the winter-spring period was characterized by atypical mix of benthic, epilitic and planktonic species with Asterionellopsis glacialis (Castrac.) Round (2.4x104 cells L-1), Chaetoceros affinis Lauder (2.5 x104 cells L-1), Chaetoceros lorenzianus Grunow (2.3 x104 cells L-1), unidentified Chaetoceros Ehrenb. spp. (2.2 x 104 cells L-1), and Pseudo-nitzschia H. Perag. spp. (4.5 x104 cells L-1) as the most abundant taxa. The great contribution of coastal species at significant distance from the coast suggests the strong influence of different water masses in this area. Such a high abundances of diatoms, accompanied by a high concentration of chlorophyll a (>1 µg L-1), indicated that area of SAP is not exclusively oligotrophic in the winter. Winter- early spring in the open water of South Adriatic could be considered as a productive season with significant phytoplankton activity.

In this study we investigated diatom colonization during period of first 6 months of artificial substrate (glass slides) exposure. From April to October 2016 microscopic glasses were submerged in the marine lake Mrtvo more (island of Lokrum, Dubrovnik area, South Adriatic, NE Mediterranean, Croatia). This semi-closed shallow marine ecosystem is connected with the open sea by an underwater passage, and is during summer season under significant anthropogenic influence (swimmers). The parallel oriented glass slides (against the surface) were placed on a seafloor at 1 m beneath the water surface. The samples were collected weekly. For light microscopy (LM) observations diatom frustules were cleaned from the organic material using method with hydrogen peroxide and hydrochloric acid. In order to determine the relationships between diatom community and environmental variables, water samples for analysis of physicochemical variables were taken weekly from the same place where diatom sampling was carried out. Water temperature ranged from 18.3°C (May) to 27.3°C (July). Salinity varied from 26.6 (October) to 37 (August). Oxygen saturation (O2/O2′) ranged 0.58 (September) to 1.3 (June). TIN ranged from 0.96 (May) to 10.2 (September) µM. Phosphate (PO4) ranged from 0.112 (May) to 0.578 (July). Silicate (SiO4) ranged from 3.925 (May) to 13.016 (July) µM. The benthic diatom flora was investigated and diversity was determined in relation to the concentrations of phosphate, silicate, and nitrogen compounds. The composition (% relative abundance) of a total of 133 diatom taxa within 47 genera found in the benthic diatom community of studied artificial substrates were identified in 21 samples. Species Cocconeis scutellum Ehrenb. var. scutellum, Cocconeis dirupta var. flexella Grunow, Pinnularia Ehrenb. sp., Diploneis crabro (Ehrenb.) Ehrenb., Navicula salinicola Hust., and Licmophora paradoxa (Lyngb.) C. Agardh were the most abundant. Genera with the greatest number of taxa were: Nitzschia Hassall (20 taxa), Mastogloia Thwaites ex W. Sm. (11), Amphora Ehrenb. ex Kütz. (9) and Cocconeis Ehrenb. (9). Altogether, only three taxa were presented in more than 85% of samples: Cocconeis scutellum var. scutellum, Cocconeis dirupta var. flexella and Cocconeis pseudomarginata W. Greg. In total, 60 taxa were found only once (sporadic) with average relative abundances lower than 1.3%. The number of taxa per sample ranged from 9 (May, June) to 52 (August), with an average of 25.4. The species diversity index varied from 0.74 to 4.51. Pielou’s species evenness ranged from 0.23 to 0.86 (the average 0.63).The amount of biofilm increased through study period. Diatom assemblages were significantly different (ANOSIM, P

Marine turtles are known to be hosts of diverse groups of organisms (epibionts), both plants and animals, particularly on their carapaces. Many of these epibionts attach to a variety of substrates in habitats where sea turtles spend time between nesting events or while foraging ; however, a small group of taxa are limited in their distribution solely to the marine animals. The association between diatoms and turtles potentially exemplifies how epibiont data can be used to identify and corroborate patterns of turtle habitat use and movement. It is expected that vertebrates in general and marine turtles in particular play an important role in the dispersal of benthic diatoms, and could be significant contributors to the spread of invasive species. By studying diatom assemblages living on turtles, we expect to gain information about the role that turtles play in the dispersal of diatoms. We expect that benthic diatoms hosted by marine vertebrates will be characterized by a high degree of specialization, similar to other epibiont communities. In this study we have combined the analysis of species composition of diatoms incorporated into the biofilm formed on the carapaces of sea turtles with isolation and culture experiments. The diatom assemblages targeted inhabit the carapaces of loggerheads (Caretta caretta) and green turtles (Chelonia mydas) from the Mediterranean coasts in Turkey and Croatia. Altogether, several sampling seasons in the Aegean Sea in Turkey and one season in Croatia allowed us to isolate and successfully grow in culture ca. 120 strains. These include small Navicula Bory, Nitzschia Hassall, Diploneis (Ehrenb.) Cleve and Halamphora (Cleve) Levkov species, apparently incorporated into the carapace biofilm. Interestingly, stalk-forming species of Achnanthes Bory s. str. and tube-dwelling Parlibellus E. J. Cox were included among these epibionts, and grew well in culture. These species in particular may provide an insight into the role of sea turtles in diatom distribution. This will be tested determining the species composition from cleaned and processed samples as well as with molecular analysis of the isolated strains. Extraction of DNA from cultured strains and use of molecular markers (rbcL, psbC and SSU) was applied in testing the hypothesis that the diatoms present on turtle carapaces will exhibit biogeography and possess geographic ranges that match those of their hosts. Additionally, recent results based on species composition analysis solely suggest that the same epibiontic diatom species can be found on the loggerhead turtles and, for example, green turtles from the distant geographic regions e.g. Mediterranean and the Caribbean Sea.

Moderne tehnologije današnjice integrirale su se u svjetsko gospodarstvo novijeg vremena u najvećoj mjeri u odnosu na dosadašnja razdoblja. Nautički turizam, kao posebna izvedenica turizma općenito, a jednako tako i kao specifičan dio pomorstva i pomorske politike svijeta, da bi opstao i razvijao se, mora postići prilagodbu u spomenutom smislu modernizacije i tehnološke razvijenosti. Ovaj rad donosi analizu korištenja modernih tehnologija u lukama nautičkog turizma, ponajprije kod upravljanja vezovima.

The unusual and prolonged occurrence of rare and poorly known dinoflagellate Prorocentrum arcuatum in the phytoplankton of the shallow aquaculture site in Medulin Bay was recorded from July 2013 to October 2014. This enabled us to investigate changes in abundance and environmental drivers of P. arcuatum population dynamics in natural conditions, and to provide first detailed description of P. arcuatum from field samples based on SEM images. During 15 months of observations we also recorded seasonal variability in P. arcuatum cell size. The optimum physical conditions for P. arcuatum proliferation were reached in autumn 2013, during the narrow temperature range between 19.6oC – 20.4oC, and salinity between 36.7 - 37.7. Despite the general similarity in physical conditions in autumn 2014, this increase in the abundance of P. arcuatum was not repeated, which might be connected to higher competition due to observed interannual changes in phytoplankton population structure.

Data of phytoplankton abundance in winters of 1994 and 1995, and surface chlorophyll satellite- derived data(1997-2012) are the basis for investigation of characteristics and intensity of phytoplankton blooms in the open South Adriatic. Special attention is paid to the relation of different circulation regimes in the Ionian Sea (prevalently anticyclonic or cyclonic direction of Northern Ionian Gyre - NIG) to intensity of phytoplankton blooms. Different circulation regimes in the Ionian Sea cause inflow of water of different physical and biochemical properties into the Adriatic. Relatively high winter production events were evident in the open South Adriatic during both anticyclonic and cyclonic regimes. In the nutrient rich anticyclonic years, shallow vertical mixing is sufficient for enrichment of euphotic layers with the nutrients and development of the bloom, while in nutrient poor cyclonic years deep vertical mixing is necessary. Moreover, intense blooms have occurred in the years of specific hydroclimatic properties (i.e. East Mediterranean Transient – EMT and during extremely cold winters) and reversal years (from anticyclonic to cyclonic circulation of NIG and vice versa). In conclusion, winter season is important for production in the open South Adriatic waters and could not be omitted in the total yearly production estimates. Winter bloom intensity in the open South Adriatic depends on synergistic effects of local meteorological conditions and large time scale climatic variabilities in the Eastern Mediterranean on one hand, and water masses of different properties entering the Adriatic on the other.

The small-sized marine diatom genus Olifantiella was originally described from the tropical waters of Réunion Island as Olifantiella mascarenica C. Riaux-Gobin & Compère. Later, more species were found from the South Pacific and Indo-Pacific and from Port of Antwerp, Belgium expanding the biogeopraphy. Genus Olifantiella have some distinct characters ; single row of areola (macroareola), trumpet like structure “buciniportula” in internal valve and broad perforated girdle. It is easily overlooked, according to Giffen after ultrastructure examination of Navicula species, some were found to share the same characters. Navicula infirmitata was described from South Africa by Giffen and Navicula supralitoralis described by Aleem & Hustedt from southern England. These two taxa were also reported from the Baltic Sea under the genus name “Navicula”. These species are proposed for transfer into Olifantiella in terms of possessing macroareola and buciniportula. In addition, LM and SEM studies revealed new Olifantiella taxa in scrapes from loggerhead sea turtle (Caretta caretta Linnaeus, 1758) carapaces sampled from the Turkish coast nesting grounds. Here, we introduce two epizoic species new to science. More Olifantiella species have been recorded with ultrastructure examination and Ion beam fabrication. O. pseudobiremis is recorded from Black Sea coasts, whilst O. mascarenica is recorded in Aegean Sea and Adriatic Sea for the first time. These results expand the distribution of Olifantiella from tropical to temperate waters. This research has been funded by Polish Research Centre in Cracow by the research grant no. 2012/04/A/ ST10/00544 (MK, AW), 2012/07/N/NZ8/02359 (AC).

Several occurrences of planktonic dinoflagellate Dicroerisma psilonereiella (Gymnodiniales) were recorded during the long term study in South Adriatic open waters from 2010 to 2017. This taxon was recorded in 4 cases, mostly below 75 m and during winter- spring period. Abundance of D. psilonereiella in Adriatic did not exceed 102 cells L-1. Genus Dicroerisma has been described and reported primarily from the boreal and polar waters but nowadays it has been widespread in all the world oceans. Although it has been encountered in the Mediterranean those are the first findings in Adriatic Sea. Recent investigations have shown that entering currents, of either Atlantic/Western Mediterranean or Eastern Mediterranean origin, modify the composition of the plankton community in the South Adriatic and each type of current brings different newcomers.

Diatom community structures at locations under the influence of different invasive Caulerpa species ; C. taxifolia and C. cylindracea, were compared in a two-year interval. Samples for taxonomic study were taken from coastal rocks at three stations (Island of Hvar, island of Mljet and Dubrovnik area) at eastern Adriatic Sea from November 2008 to October 2010. Light and electron microscopy examinations were used for qualitative analysis. Taxonomic analysis of diatom communities revealed altogether 388 epilithic taxa belonging in 63 genera including Hyalosynedra, Rhopalodia, Navicula, Cocconeis, Berkeleya, Tabularia, Nitzschia and Grammatophora as the most abundant. The study confirmed differences in species composition and abundance of epilithic diatoms among two Caulerpa sites. While the average number of taxa at C. taxifolia sampling site (island of Hvar) was 77 per sample, the average number of taxa at C. cylindracea sampling sites (Dubrovnik and Mljet) was lower and amounted to 64 per sample. The highest values of Shannon- Wiener Diversity Index were during autumn and were almost the same for all three sampling sites ranging from 5.26 to 5.34. As revealed by MDS ordination, location has more impact on diatom community structure than seasonal changes. ANOSIM test performed on species abundance data confirmed that the difference between diatom communities among different sampling seasons was not significant. The results indicate that the influence of invasive seaweed of genus Caulerpa that change the habitat by competing with autochthonous algae diminishing the structural complexity, richness of species and diversity evident at the macroscopic level have impact on microflora as well. Results of this study presents the first study of the taxonomic composition and distribution of epilithic diatoms from areas of invasive Caulerpa spp., and it contributes to the broader and regional knowledge of diatom diversity in these challenged environments.

The present study focuses on the taxonomy of epiphytic diatoms in areas affected by invasive macroalgae representing the the genus of Caulerpa J.V. Lamouroux, 1809 on the eastern Adriatic Sea coast. Material for the study of epiphytic diatoms was collected during two years (autumn 2008 – autumn 2010) from an area influenced by Caulerpa taxifolia (Vahl) C. Agardh in the bay of Stari Grad (the Island of Hvar), and from areas influenced by Caulerpa cylindracea Sonder in Dubrovnik and on the Island of Mljet (Gonoturska Bay). In order to compare epiphyte assemblages, sampling of coexisting autochthonous brown and green algae was conducted at the same stations. The samples were acid cleaned (HCl/H2O2) prior to qualitative analysis of diatoms using light microscope (LM) (Nikon E600 microscope) under magnification of 1000x. Light and electron microscopy examinations provide for the first time the information on the general morphology and ultrastructure of taxa, and enable a determination of the taxonomy of diatoms. The seasonal dynamics were described on a fine time scale. For the first time in the Central and Southern Adriatic Sea the composition of benthic diatoms and seasonal dynamics of taxa in areas affected by invasive macroalge Caulerpa taxifolia and Caulerpa cylindracea were determined. The results of this study enable a better understanding of the functioning of ecosystems dominated by macroalgae Caulerpa spp. Knowledge of the diatom community structure in the areas impacted by Caulerpa spp. is important for studies of the toxic effects of the host.

Povećana zabrinutost za sigurnost opskrbe naftom i negativan utjecaj fosilnih goriva na okoliš, stavlja pritisak na društvo za pronalaskom obnovljive alternative za dobivanje goriva. Biogoriva kao biodizel, bioplin dobivena iz biomase poželjna su zamjena za fosilna goriva jer su trenutno jedini put ka održivom razvoju. Ovaj rad bavi se proizvodnjom bioetanola na šećernim, škrobnim i lignoceluloznim sirovinama. Brazil i SAD ističu se kao vodeći proizvođači bioetanola prve generacije, no u ovom radu navedene su prednosti lignoceluloznih sirovina kao biomase. Opisane su značajke trenutne proizvodnje bioetanola u svijetu i njegove upotrebe kao goriva. Increased concern about oil supply and negative impact of fossil fuels on the environment has put pressure on society to find alternative, renewable sources of energy. Biofuels as biodiesel, biogas and bioethanol are currently seen as only path to sustainable development. This work deals with ethanol production from sugar, starchy and lignocellulosic biomass. Brazil and USA are the most prominent producers of first generation bioethanol but some advantages of lignocellulosic biomass are quoted in this work. There are also mentioned current characteristics of global bioethanol production and its usage as biofuel.

Morphology and seasonal distribution of the rare planktonic bloom forming dinoflagellate Prorocentrum arcuatum in Medulin Bay are described in this study. It demonstrates first record of high abundance of this species in the coastal waters of the Adriatic Sea. Samples were collected fortnightly in the period from July 2013 to October 2014 for analysis of phytoplankton community structure and for environmental parameters. Using both light and scanning electron microscopy, a morphometric study of P. arcuatum was performed according to cell shape, size, ornamentation of thecal plates and apical spine. Cells of P. arcuatum are asymmetrical, medium to large. At the anterior side it is broadest at the middle part of the cell and attenuated at the posterior end. This species posses marked torsion of the cells, which is distinctive feature in relation to other Prorocentrum species. The cell surface is covered with shallow depressions and scattered pores. The anterior apical spine is long, sharp and broadest at the base. P. arcuatum was almost continuously occurring in Medulin Bay throughout 15 months of the research period. The cell density of P. arcuatum varied from 80 cells L-1 to 13.200 cells L-1. Regarding vertical distribution, abundances of this species between surface and bottom layer were highly correlated. Variation in length of P arcuatum cells was noticeable having the smallest cells in winter months ; from December till March, while the largest cells occurred in May, June and July. In the period of the highest proliferation of P. arcuatum high temperatures were accompanied by high salinity and therefore both parameters should be accomplished. Also, negative correlation of P. arcuatum with all forms of inorganic nitrogen (NO3-, NO2-, TIN, NTOT) was found.

In the eastern Adriatic, there are only a few studies on benthic diatoms mostly focused on ecology and taxonomy of periphytic diatoms in the Croatian estuaries or Albanian coastal wetlands. Until now, both planktonic and benthic marine diatoms have never been studied in Bosnia and Herzegovina. This study forms part of a research program investigating the biodiversity and ecosystem functioning in the border marine coastal waters between the two countries – Croatia and Bosnia and Herzegovina. The program includes phycological, zoological and hydrographical research. This paper considers the taxonomic composition and seasonality of marine benthic diatoms in the relation to some key environmental variables (temperature, salinity and density) in the Bay of Neum in Bosnia and Herzegovina on the south-eastern Adriatic coast.

There is a considerable lack of data on marine benthic diatoms in the Adriatic. In response to this fact the present study has been undertaken which focuses on the taxonomy of epiphytic diatoms in areas affected by invasive macroalgae representing the the genus of Caulerpa J.V. Lamouroux, 1809 on the eastern Adriatic Sea coast. Material for the study of epiphytic diatoms was collected during two years (autumn 2008 – autumn 2010) from an area influenced by Caulerpa taxifolia in the bay of Stari Grad (the Island of Hvar), and from areas influenced by Caulerpa racemosa in Dubrovnik and on the Island of Mljet (Gonoturska Bay). In order to compare epiphyte assemblages, sampling of coexisting autochthonous brown and green algae was conducted at the same stations. Light and electron microscopy examinations provide for the first time the information on the general morphology and ultrastructure of taxa, and enable a determination of the taxonomy of diatoms. The seasonal dynamics were described on a fine time scale. For the first time in the Central and Southern Adriatic Sea the composition of benthic diatoms and seasonal dynamics of taxa in areas affected by invasive macroalge Caulerpa taxifolia and Caulerpa racemosa were determined. The results of the presented PhD thesis contribute to the knowledge of benthic diatoms in the Adriatic, as well as of a global biogeographic distribution of diatoms (chorology). The results of this study will enable a better understanding of the functioning of ecosystems dominated by macroalgae Caulerpa spp. Knowledge of the diatom community structure in the areas impacted by Caulerpa spp. is important for studies of the toxic effects of the host. Morske bentoske dijatomeje u Jadranu su slabo poznate. Istraživanja u okviru disertacije su usmjerena na taksonomski sastav epifitskih dijatomeja u područjima invazivnih makroalgi roda Caulerpa uz istočnu obalu Jadrana. Materijal je sakupljan tijekom dvije godine (jesen 2008 – jesen 2010) u području s Caulerpa taxifolia u Starigradskom zaljevu na otoku Hvaru, te u područjima zahvaćenim makroalgom Caulerpa racemosa u Dubrovniku i u uvali Gonoturska na otoku Mljetu. Na istim su postajama istovremeno prikupljani uzorci autohtonih smeđih i zelenih algi radi analize odnosa epifitskih dijatomeja i domaćina. Pomoću svjetlosne i elektronske mikroskopije, po prvi se put u srednjem i južnom Jadranu odredio taksonomski sastav dijatomeja, opisala morfologija i ultrastruktura pojedinih vrsta te utvrdila sezonska na finoj vremenskoj skali. Dobivene spoznaje doprinjele su poznavanju bentoskih dijatomeja u Jadranu, ali i globalne biogeografske rasprostranjenosti dijatomeja (korologiji). Dobiveni rezultati omogućit će bolje razumijevanje funkcioniranja ekosustava u kojima dominiraju makroalge Caulerpa spp.. Saznanja o taksonomskom sastavu dijatomeja u područjima s Caulerpa spp. važna su za istraživanja toksičnog učinka domaćina.

A diatom genus Schizostauron was described by Grunow and originally four marine species were included, i.e. Schizostauron lindigianum, S. reichardtianum, S. ovatum and S. fimbriatum. The species belonging to Schizostauron did not receive much attention to date probably due to limited collections. Later on Hustedt transferred S. reichardtianum to Achnanthes sensu lato as A. reichardtianum. It was only Ross who has made a thorough nomenclature investigation of Schizostauron. Ross discovered that S. lindigianum is later homonym of Cocconeis dirupta Gregory and typified the genus with S. reichardtianum. A detailed description of Schizostauron taxa from South Africa and Mozambique based on LM and EM studies will be presented. Based on cultures from the Indian Ocean (Mozambique) sites we will also present the phylogeny of Schizostauron within Achnanthales using morphology (frustule), cytology (plastids) and rbcL, psbC and SSU gene sequencing.

This study focuses on the taxonomy of epiphytic diatoms in areas of invasive macroalgae of the genus Caulerpa sp. on the eastern Adriatic Sea coast. Material was collected during two years (autumn 2008 – autumn 2010) from an area influenced by Caulerpa taxifolia in the bay of Stari Grad (the Island of Hvar). In order to compare epiphyte assemblages, sampling of coexisting autochthonous brown and green algae was conducted on the same station. Light and electron microscopy provide the information on the general morphology and ultrastructure of species, and enable a determination of the taxonomy of diatoms. The diatom assemblage was characterized by high abundances of genera Cocconeis, Mastogloia, Nitzschia, Navicula, Amphora, Hyalosynedra, Diploneis and Licmophora. The highest number of taxa was in summer (85 in July 2009, 102 in August 2009 and 74 in July 2010) and the lowest in the end of autumn/winter (eg. 32 in November 2008 and 25 in November 2009). Althought, the number of taxa within the genera Cocconeis is quite low (15), species of the genus Cocconeis, dominated the epiphytic diatom flora. The diatom assemblage was characterized by the abundance of a new species of Cocconeis, tiny Cocconeis caulerpacola Witkowski, Car et Dobosz, particularly during summer and autumn (eg. 63% in October 2009 and 40% in October 2010). Periods of higher abundance of C. caulerpacola appear to coincide with maximum toxicities observed for C. taxifolia in summer and autumn, while the minimum abundance is observed in winter and spring. The seasonal dynamics will be described on a fine time scale. Knowledge of the diatom community structure in the areas of Caulerpa spp. is important for studies of the toxic effects of the host.

Seasonal distribution of the epiphytic diatom flora on the “killer” seaweed Caulerpa taxifolia was described within the Bay of Stari Grad (the Island of Hvar, Croatia) over a 2-year period (autumn 2008 – autumn 2010). The diatom assemblage was characterized by high abundances of genera Cocconeis, Hyalosinedra, Mastogloia, Nitzschia, Navicula, Amphora and Licmophora. The highest number of taxa was in summer (85 in July 2009, 102 in August 2009 and 74 in July 2010) and the lowest in the end of autumn/winter (eg. 32 in November 2008 and 25 in November 2009). The largest number of taxa was found within the genera Nitzschia (34), Mastogloia (32), Amphora (30), Navicula (18), Diploneis (17) and Cocconeis (15). Althought, the number of taxa within the genera Cocconeis is quite low, species of the genus Cocconeis, dominated the epiphytic diatom flora. The diatom assemblage was characterized by the abundance of a new species of Cocconeis, tiny Cocconeis caulerpacola Witkowski, Car et Dobosz, particularly during summer and autumn (eg. 63% in October 2009 and 40% in October 2010). Periods of higher abundance of C. caulerpacola appear to coincide with maximum toxicities observed for C. taxifolia in summer and autumn, while the minimum abundance is observed in winter and spring. The seasonal dynamics will be described on a fine time scale. Knowledge of the diatom community structure in the areas of Caulerpa spp. is important for studies of the toxic effects of the host.

The aim of the study was to determine the taxonomic composition and seasonality of benthic marine diatoms in Bosnia and Herzegovina. Samples were taken from one station (coordinates: 42° 54' 58.7" N 17° 36' 17.6" E) at 1 and 8 m depths during all seasons in 2011. Samples were fixed in a 4% formalin solution and prepared for investigation by cleaning frustules using the method described by Hustedt (1933). In total, 400 valves per sample were counted. Examination, identification and counting of benthic diatoms were carried out using the oil immersion lens (100x) of the Microstar binocular microscope, AO Scientific Instruments. Diatoms were also studied by means of scanning electron microscopy (SEM). Photomicrographs were taken for the majority of taxa. Altogether, 270 taxa (species and infraspecific taxa) included in 75 genera were determined. The highest number of taxa was in spring (177) and the lowest in autumn (91). The largest number of taxa was found within the genera Mastogloia (27), Diploneis and Nitzschia (20), Amphora (19), Navicula (15), Halamphora and Cocconeis (10). Regarding depths, higher number of taxa was identified at 8 m depth in the most samples. According to Simpson and Shannon-Wiener indicies, the highest differences between surface and bottom samples were recorded in winter. Taxa Cocconeis scutellum Ehrenberg, Grammatophora oceanica Ehrenberg, Halamphora coffeaeformis (Agardh) Levkov, Licmophora remulus Grunow, Trachyneis aspera (Ehrenberg) Cleve were presented in all samples. In all seasons, the most abundant taxa were Cocconeis scutellum Ehrenberg (4-22.5%) at 1 m, and Halamphora coffeaeformis (Agardh) Levkov (6.25-13.25%) at 8 m depth.

There are eight sea turtle species in the world and one of them, Carettacaretta (Linnaeus, 1758) or loggerhead turtle, is found in nearly all the world's temperate and tropical oceans. During winter months, loggerhead sea turtles migrate to tropical and subtropical waters where adult females lay several clutches of eggs on specific sandy beaches during a nesting season. A total of 20 beaches were determined to represent the main nesting areas for loggerhead turtles in Turkey. These turtles are potential vectors for colonisation in various species of marine flora and faunas they host a variety of plants and animals as epibionts, particularly on the carapace region. In this study, we have begun to document the diatom flora on the carapace of C. caretta from the Turkish coast, which is a transition region between the Aegean and the Mediterranean Seas. Diatom assemblages were collected from the carapace of six C. caretta individuals. Part of the samples were preserved and cleaned for LM and EM examination, which we found were dominated by a very small representative of the epizoobiontic genus Tripterion R.W. Holmes, S. Nagasawa& H. Takano, which is probably a species new to science. Interestingly, representatives of the genus Olifantiella Riaux-Gobin & Compère known thus far only from the tropical Oceans (Indian and Pacific) also occur in the epibiontic flora. We have also documented several species of Amphora, Mastogloia, Navicula and, Nitzschia. A portion of each sample was also kept alive and clonal cultures in f/2 medium were established from some of the diatoms present at the Paleoceanography Unit at the University of Szczecin. These cultures include taxa from genera such as Achnanthes, Amphora, Navicula and Odontella. Genomic DNA will be extracted from these clones and the sequence data will be used in phylogenetic analyses.

The monoraphid diatom genus Schizostauron was described by Grunow with four marine species included. The major feature of Schizostauron was the bifurcate central area of the raphid valve, whereas the sternum valve was characterized by robust perpendicular ribs connected by a complex, rather randomly arranged network of siliceous elements. Likely due to the scarcity of observations, the species belonging in Schizostauron have not received much attention. According to investigations by Robert Ross the generic name is validly published in accordance with ICBN, and the typus generis is S. reichardtianum Grunow. The number of established taxa in Schizostauron amounts to less than a dozen ; however, our recent examination of marine littoral material have revealed numerous unknown species, all more or less resembling Schizostauron fimbriatum Grunow [=Achnanthes fimbriata (Grunow) Ross] and Achnanthes danica (Flögel) Cleve. Here we present results of our morphological (LM & SEM) and genetic research on several Schizostauron taxa from the coastal waters of the tropical Indian Ocean. They have been cultured successfully and subject to genomic DNA extraction. Three genes --nuclear- encoded SSU rDNA and chloroplast-encoded rbcL and psbC--have been amplified and sequenced. Our sequencing data, together with additional monoraphid and raphid pennate diatom sequences, either from our own data base or downloaded from GenBank, have been used to estimate a phylogenetic tree. To our surprise, Schizostauron taxa within the phylogenetic tree clustered with taxa belonging in the Stauroneidaceae, i.e. Stauroneis, Craticula and Fistulifera. Sister to Schizostauron within the Stauroneidaceae was the monoraphid taxon Astartiella sp. (isolated from the Gulf of Mexico in Texas) and another unnamed monoraphid diatom isolated from Texas. Identify features, either cytological or morphological, common to the monoraphids and other Stauroneidaceae (Stauroneis and Craticula) is difficult. Schizostauron seems to have chloroplasts similar to Stauroneis and Craticula, whereas Astartiella and the unnamed taxon possess a single chloroplast, similar to Cocconeis and Planothidium. All three monoraphid taxa, however, share the coaxial central raphe internal endings and strongly-hooked external apical endings. It seems that Schizostauron and the other monoraphid genera provide evidence that monoraphy in diatoms may have evolved in several independent evolutionary events. Here we provide examples which are molecularly distant from the monoraphid diatoms of the Achnanthales.More research is required to uncover cytological or morphological synapomorphies that link the monoraphid forms with biraphid Stauroneidaceae.

Scientific interest of Prof. Dr. Anto Jurilj was taxonomy and phylogeny of diatoms. Prof. Jurilj has been involved in several research such as diatoms of Lake Orhid and Sarmatic Sea in environs of Zagreb. He decribes a high number of new diatom taxa.

This study focused on the diatom species associated with exotic seaweeds on the coast of the Croatian Adriatic Sea. The macroalgae are Caulerpa racemosa (Island of Mljet, Island of Lokrum near Dubrovnik, Southern Adriatic) and C. taxifolia (Bay of Stari Grad, Island of Hvar, Middle Adriatic). Fresh and processed material was studied by means of light (LM) and electron microscopy (SEM and TEM). Our examination of both unprocessed and processed (hydrogen peroxide treated) samples revealed an abundant and species-rich diatom flora. Examination of unprocessed material demonstrated an attached diatom flora, not incorporated into bioaggregates. A total of ca. 150 taxa have been identified. The difference in species composition between the seaweed taxa was significant, as only 26 taxa occurred on both host plants. We have identified 69 diatom taxa, representing 26 genera, associated with C. racemosa and 131 taxa, representing 32 genera, with C. taxifolia. Mode of attachment of the epiphytes differed between the two host algae. On C. racemosa surface-adhered Cocconeis or tube dwelling Mastogloia species were dominant. On C. taxifolia tube-dwelling taxa dominated. In the case of C. racemosa, the most abundant species were Cocconeis spp., while in C. taxifolia, Mastogloia spp. were most abundant. The most species rich genus included Mastogloia with 14 taxa on C. racemosa and 25 taxa on C. taxifolia. A variety of tube patterns of Mastogloia spp. were observed on thalli of both seaweed species. This was independent from preservation state of the thalli (i.e. fresh versus decaying). The abundant taxa are well known as epiphytes. Included in this group are representatives of Berkeleya, Cocconeis, Licmophora, Mastogloia and Navicula.

Početkom 2006. dubrovački laboratoriji splitskog Instituta za oceanografiju i ribarstvo postali su, nakon skoro 60 godina organiziranog istraživačkog rada u biološkoj oceanografiji, Institut za more i priobalje, koji je danas znanstvena sastavnica Sveučilišta u Dubrovniku. U Institutu je najveći znanstveno-istraživački tim zooplanktonologa na istočnoj obali Jadrana. Institut ima dugu tradiciju proučavanja planktonskih organizama. Planktonti nemaju sposobnost aktivnog kretanja već ih pasivno nose morske struje. Posebno su prilagođeni na pelagički način života, a najvažnija prilagodba na lebdenje jest smanjenje apsolutne veličine tijela, u smislu porasta odnosa površine nasuprot volumenu. Otpor tonjenju postignuto je i raznim tjelesnim nastavcima, kao što su hijaline kožice, trnje, sete i dr., pri čemu se oblik stanice i tijela udaljuje od kuglastog koji je najmanje pogodan za lebdenje. Lakše lebdenje osiguravaju kapljice ulja, masti, plinova i sluzi koji su uobičajeni proizvodi metabolizma, a sadrže specifično lagane ione. Svaka znanstvena ustanova koja se bavi istraživanjem mora treba imati brod za terenska istraživanja i opremu pomoću koje znanstvenici prikupljaju uzorke. Istraživanja planktona vrše se planktonskim mrežama koje filtriraju žive organizme u vodenom stupcu (sl. 1). Za proučavanje sastava zooplanktona koriste mreže s veličinom okaca do 500 mikrometra koje propuštaju sve organizme manje od te veličine. Za istraživanje manjih stanica (npr. fitoplanktona) koja prolaze kroz okca najfinijih planktonskih mreža, kao i mikrozooplanktona, uzimaju se uzorci morske vode sa željnih dubina pomoću posebnih crpaca (sl. 2). Primjenom suvremenih terenskih i laboratorijskih metoda istraživanja, uključujući metode molekularne biologije, znanstvenici u Institutu su u nekoliko posljednjih godina otkrili za znanost dvije nove vrste morskih organizama. Prva među njima jest vrsta repnjaka (Appendicularia). Repnjaci su skupina isključivo planktonskih plaštenjaka (Tunicata), a odlikuje ih veliki broj jedinstvenih osobina: hranjenje pomoću kućice – strukture jedinstvene u životnjskom svijetu. Jedini među plaštenjacima zadržavaju svitak cijeloga života, posjeduju najmanji poznati genom među višestaničarima te u povoljnim uvjetima imaju izrazito kratak životni ciklus. Dužina im je od oko 1 mm do nekoliko centimetara, a hrane se filtriranjem mora pomoću kućice koju luče epitelne stanice na površni trupa (oikoblasti). Na filterima kućice se zadržavaju najsitniji planktonski organizmi te čestice detritusa u koncentraciji od oko 1000 puta većoj nego u okolnom moru. Mišićavi rep životinje ritmičnim pokretima preko filtera omogućuje strujanje mora. Filtere mukozne kućice nakon nekog vremena začepe veće čestice, nakon čega ih životinja odbacuje i izgrađuje novu kućicu, i to od 2 do čak 40 puta dnevno. Odbačene kućice repnjaka zajedno s organskom tvari zarobljenom u njihovim filterima predstavljaju poseban tip morskog snijega te su važan izvor ugljika u dubljim slojevima mora. Nova vrsta repnjaka pod nazivom Fritillaria ragusina (lat. ragusina - dubrovačka, sl. 3) je opisana iz mrežnih uzoraka zooplanktona sakupljenih u veljači 2008. u otvorenim vodama južnog Jadrana. Javlja se isključivo na otvorenom moru, a može se pronaći u sloju od površine do dubine 300 m, ali je najabundantnija u sloju od površine do 50 m. Vrsta F. ragusina je jedna od najmanjih poznatih repnjaka. Dužina repa ne prelazi 1 mm, dok je najveća zabilježena širina repa oko 0, 2 mm. Zbog svoje male veličine uglavnom prolazi kroz oka standardno korištenih planktonskih mreža. To je vjerojatno jedan od razloga zašto je tek nedavno otkrivena. Među svjetskim razmjerima repnjaci su najviše proučavani u Mediteranu, a pronalazak nove vrste repnjaka u Jadranu kao dijelu Mediterana ukazuje na naše nedovoljno poznavanje biološke raznolikosti mora. Od 2008. vodstvo Instituta je odlučilo znanstvenu djelatnost proširiti i na bentoske (pridnene) organizme. Jedan od razloga je bio veoma slabo poznavanje tih organizama, poglavito morskih jednostaničnih alga mikroskopske veličine iz skupine dijatomeja (alga kremenjašica) u Jadranskom bazenu. Poseban izazov je bio istražiti dijatomeje na tropskim invazivnim pridnenim makroalgama Caulerpa taxifolia i C. racemosa (sl. 4 i 5). Vrsta C. taxifolia slučajno je dospjela u Mediteran 1984. ispred Monaca nakon čega se počela vrlo brzo širiti. U Jadranu je otkrivena 1994. u podmorju otoka Hvara (Starigradski zaljev) gdje je i danas prisutna. Šireći se, uspjela je prekriti velike površine različitih tipova dna na kojima su do tada rasla bujna naselja različitih vrsta alga te prostrane livade morskih cvjetnica. Vrlo brzo nakon dolaska kaulerpe, na istim se površinama bioraznolikost drastično smanjila. Prvi nalaz C. racemosa u Jadranskom moru zabilježen je na Paklenim otocima u jesen 2000., a danas se najveći broj nalazišta u Hrvatskoj nalazi od Cavtata do otoka Visa. Kaulerpe u mediteranskom području nemaju prirodnog predatora, kao što je u tropskim predjelima vrsta puža iz roda Elysia, što otežava njezino suzbijanje. Na vegetativnom tijelu makroalge C. taxifolia znanstvenici dubrovačkog Instituta za more i priobalje u suradnji sa kolegama iz Poljske, Australije, Francuske i Njemačke, otkrili su novu vrstu dijatomeje koju su znanstveno nazvali Cocconeis caulerpacola (caulerpacola - na kaulerpi, sl. 6). Ta je sićušna alga veličine oko 20 mikrometra (pedeseti dio milimetra), pa je za promatranje građe ljušturice bilo potrebno, uz svjetlosni, koristiti i elektronski mikroskop (sl. 7). Nova vrsta je po prvi put opisana na uzorcima kaulerpe s Hvara, ali je nađena u uzorcima kaulerpa sakupljenim ispred grada Cannes (južna Francuska) te u zaljevu Moreton (istočna obala Australije). Dijatomeja je abundantna na vegetativnom tijelu kaulerpe (talusu), što pokazuje da je C. taxifolia pogodan domaćin unatoč svojoj reputaciji „alge ubojice“. Nova dijatomeja je, također, utvrđena i na talusu C. racemosa, i to u uzorcima s otoka Mljeta i iz okolice Dubrovnika. Glavna značajka kaulerpa jest prisutnost metaboličke tvari kaulerpenina čija je glavna uloga kemijska obrana protiv predatora te kolonizatora poput te novoopisane vrste. Najveća abundancija dijatomeje Cocconeis caulerpacola na kaulerpama bila je u ljeto i jesen, istovremeno kad je i najveća koncentracija kaulerpenina, pa ostaje za ubuduće objasniti koji su to kemijski mehanizmi i specifičnosti koji omogućavaju nesmetan rast i razmnožavanje na kaulerpama. Otkrića tih i drugih vrsta u Jadranu, upućuju nas na potrebu uvažavanja značaja istraživanja bioraznolikosti i problem njezine slabe istraženosti, naročito pri određivanju kriterija za dodjelu znanstvenih projekata te njihovom financiranju. Nadalje, istraživanja hrvatske bioraznolikosti treba svrstati među državne znanstvene prioritete, planski omogućavati i poticati zapošljavanje mladih istraživača bioraznolikosti te poboljšati uvjete za znanstvenoistraživački rad u znanstvenim i visokoobrazovnim ustanovama. I na kraju, ali ne i posljednje, potrebno je izraditi strategiju razvoja znanstvenih istraživanja hrvatske bioraznolikosti nakon provedene analize stanja istraženosti pojedinih komponenti bioraznolikosti i drugih potrebnih analiza.

Satellite DNAs (satDNAs), despite rapid evolution that continuously remodel the genomic landscape, occupy functionally essential centromeric regions. Difficult to be explored due to their repetitive nature and divergence, satDNAs are still hardly accessible frontiers of eukaryotic genomes and knowledge concerning functional significance of satellite DNAs is rather limited. In this work, we provide a comprehensive analysis of six satDNAs in the library of recently separated root-knot nematodes Meloidogyne chitwoodi and M. fallax. We disclosed two different conserved regions common for analyzed satDNAs. One appeared to be highly similar to the CENP-B box of human alpha satDNA, which emerged, in sequence alignment, as a conserved segment common for six divergent satDNAs shared by closely related genomes. Observed results emphasize it as the most prominent example of the CENP-B box-like motif out of mammals. The proposed feature of the CENP-B box-like motif is to act as a promoter in the hypothesized cut-and-paste transposition-related mechanism. This observation could represent a novel role of the CENP-B box, in addition to the known function in centromere protein binding. We propose that the second conserved sequence motif detected in explored satDNAs is involved in illegitimate recombination. In parallel to alpha satDNAs, we found organization of satDNA arrays in nematodes comparable to that found in human and primates, in the form of simple and complex higher order repeats (HORs). In contrast to human satDNA organization, characterized by phylogenetically distinct HOR and monomeric forms, organizational patterns observed in nematodes are consistent with frequent and continuous shuffling of sequences between HORs and monomeric arrays. Our results suggest the role of conserved domains in mechanisms that cause rapid shuffling of sequences among divergent satDNAs, on the level of short-segment tracts. In context of satDNA evolution, our finding provides, for the first time, an experimentally verified link between conserved domains and satDNA rearrangement events.

U razdoblju od siječnja do prosinca 2011. na jednoj postaji u Neumskom zaljevu (Bosna i Hercegovina), mjesečno su uzorkovani fizikalno-kemijski parametri te fitoplankton. Cilj rada je bio analizirati sastav mrežnog fitoplanktona. U tu svrhu uzorci su sakupljeni fitoplanktonskom mrežom promjera pora 20 µm potezom od dna do površine. Uzroci su konzervirani 2 % formalinom te obrađeni pod svjetlosnim i pretražnim elektronskim mikroskopom. Utvrđena je 131 svojta fitoplanktona, od toga najviše dinoflagelata. Sastav fitoplanktona je sličan s populacijama u unutrašnjem dijelu Malostonskog zaljeva te u donjem dijelu estuarija Neretve. To su ujedno prvi detaljni podaci o sastavu morskog fitoplanktona u Bosni i Hercegovini.

U razdoblju od ožujka 2010. do prosinca 2011. u Neumskom zaljevu su u mjesečnim intervalima na jednoj postaji (N 42° 54' 58.7" E 17° 36' 17.6") uzimani uzorci bentoskih dijatomeja s dubina 1 i 8 metara. Uzorci su konzervirani 4% formalinom, dok su trajni preparati pripremljeni metodom prema Hustedtu (1930). Uzorci su pregledavani mikroskopom Microstar (AO Scientific Instruments) koristeći imerzijski objektiv 100x. Na temelju 30 sakupljenih uzoraka, utvrđeno je 414 svojta koje su svrstane unutar 92 roda. Od toga 72 roda pripada redu Pennales, a 20 Centrales. Najveći broj svojta imali su rodovi Mastogloia Thwaites (36 svojta), Nitzschia Hassall (34), Amphora C.G.Ehrenberg (32), Diploneis C.G.Ehrenberg i Navicula Bory (25) te Cocconeis C.G.Ehrenberg (18) i Surirella Turpin (15). Ovim istraživanjem dobiveni su prvi podaci o taksonomskom sastavu morskih dijatomeja u Bosni i Hercegovini.

The framework of the author’s research project includes a description of the epiphytic diatom flora on Caulerpa taxifolia (Vahl) C. Agardh. Material was collected monthly over two years (autumn 2008 – autumn 2010) from an area influenced by Caulerpa taxifolia in the Bay of Stari Grad (Island of Hvar). Light and electron microscopy is expected to provide for the first time information on the general morphology and ultrastructure of species, and enable a determination of the taxonomy of diatoms. Taxa of genus Cocconeis Ehrenberg were the most frequent and abundant epiphytes of the Caulerpa thallus. A new species of Cocconeis, tiny Cocconeis caulerpacola Witkowski, Car et Dobosz was observed as epiphyte with patchy distribution covering the surface of Caulerpa taxifolia. The seasonal dynamics will be described on a fine time scale. Knowledge of the diatom community structure in the areas of Caulerpa spp. is important for studies of the toxic effects of the host.

The marine lakes, Malo and Veliko Jezero (“Little” and “Big” Lakes), are one of the first established marine reserves in the world. In fact, they are two karstic basins on the island of Mljet which are filled by the holocene ingression of the Adriatic Sea. The lakes with the surrounding area have been protected under the category of the National Park since 1960. The aim of the study was to determine the species composition and abundance of benthic diatoms in two marine lakes. Knowledge of the diatom community structure in the marine protected areas is important for marine ecology and conservation biology. Samples were taken from two stations (Malo jezero - 42° 46' 58" N 17° 20' 56" E at 1 m depth ; Veliko jezero - 42° 46' 57" N 17° 21' 06" E at 8 m depth) during April 2011. Samples were fixed in a 4% formalin solution and prepared for investigation by cleaning frustules using the method described by Hustedt (1930). Examination and identification of benthic diatoms were carried out using the oil immersion lens (100 x) of the Microstar binocular microscope, AO Scientific Instruments. Samples were also studied by means of scanning electron microscopy. Photomicrographs were taken for the majority of taxa. Altogether, 96 taxa included in 33 genera were identified. Among them, 60 taxa were found in Veliko jezero and 59 in Malo jezero. Sörensen similarity index of 37% indicated that diatom community of two lakes was highly distinct. The largest number of taxa was found within the genera Mastogloia (11), Amphora (10), Diploneis (10) and Nitzschia (7). This work reports the first records of benthic diatoms in the lakes. The unique situation of marine lakes within a karstic system made it possible to get valuable new information about Adriatic sea diatoms.

We present identification and ultrastructural observation on frustular features on Mastogloia taxa found on three locations in south Adriatic Sea: Stari Grad Bay on Island of Hvar, Gonoturska Bay on Island of Mljet, and Orsula near Dubrovnik. Studied samples were taken monthly during 2009 and 2010 at the depth from 5m to 15m. The study is made in the framework of a research project dealing with exotic seaweeds invasion of Caulerpa racemosa and Caulerpa taxifolia in the Croatian part of southern Adriatic Sea. The genus Mastogloia includes a number of species living as epiphytes on seaweeds and seagrasses, together with other biraphid (i.e. Diploneis, Amphora) and monoraphid genera (i.e. Cocconeis, Achnanthes). The genus Mastogloia is highly biodiversified and quantitively significant in benthic communities. The detachment and cleaning of epiphytic diatoms have been obtained by treating macrophytes with acids and then washing with distilled water. Using light and scanning electron microscopy we detail the frustular morphology of different Mastogloia taxa. The frustular morphology within the genus Mastogloia has been observed and described by many authors since 1856 when Thwaites established this genus. The biodiversity of this genus is large with 300 published taxa. In our material more than 25 species of Mastogloia genus have been found, including: M. binotata (Grunow) Cleve, M. fimbriata (Brightwell) Cleve, M. crucicula (Grunow) Cleve, M. ovalis A. Schmidt, M. cuneata (Meister) Simonsen, M. splendida (Gregory) Cleve, M. erythraea Grunow, M. inaequalis Cleve, M. ovulum Hustedt, M. pusilla Grunow, and M. pumila (Grunow) Cleve. Preliminary results of assemblages of benthic diatoms revealed that the genus Mastogloia is very abundant and species-rich at the Adriatic Sea coast.