Marina Vilenica

Distribution and Autecology of Mayflies (Insecta, Ephemeroptera) in a Mediterranean River in the Western Balkans

ABSTRACT: Mayflies are one of the most important orders of freshwater inhabiting insects and they are widely used in ecological studies. Mayfly ecology and distribution in the Mediterranean part of the Western Balkans are insufficiently investigated. Our study encompassed 9 sampling sites along the course of the Cetina River, the longest Mediterrranean river in Croatia, and 2 sites in the spring reach of its tributary, Ruda River. Mayflies were sampled monthly between August 2004 and August 2005. A total of 22 mayfly taxa were recorded, including 12 rare species. Due to the variety of available microhabitats and suitable physico-chemical water properties (e.g. water temperature), the highest mayfly richness was recorded in the lower reaches of the river. We discuss distribution and ecology of collected species, particularly the most abundant species (e.g. Baetis rhodani (Pictet, 1843) and Serratella ignita (Poda, 1761)) and the rare species (e.g. Siphlonurus croaticus Ulmer, 1920). One of the rare species collected, Caenis beskidensis Sowa, 1973, has a central and western European distribution and was hitherto not recorded in the Dinaric Western Balkan ecoregion. Morphologically variable specimens from the Rhithrogena group semicolorata were collected, and variability of the most important morphological characters is presented here. In order to resolve the taxonomical status we sequenced the mitochondrial cytochrome oxidase c subunit I (barcode region) of morphologically distinct specimens from the Cetina spring and another locality belonging to the Black Sea drainage (Bijela rijeka, Plitvice Lakes NP). Uncorrected p-distances within and between populations enabled us to associate all specimens to Rhithrogena braaschi Jacob, 1974. Moreover, in contrast to high morphological variability observed in this species, we infer low genetic differentiation of the mtCOI fragment in this species in the Dinaric Western Balkans.

Croatian mayflies (Insecta, Ephemeroptera): species diversity and distribution patterns

Abstract Knowledge of the mayfly biodiversity in the Balkan Peninsula is still far from complete. Compared to the neighbouring countries, the mayfly fauna in Croatia is very poorly known. Situated at the crossroads of central and Mediterranean Europe and the Balkan Peninsula, Croatia is divided into two ecoregions: Dinaric western Balkan and Pannonian lowland. Mayflies were sampled between 2003 and 2013 at 171 sites, and a total of 66 species was recorded. Combined with the literature data, the Croatian mayfly fauna reached a total of 79 taxa. Of these, 29 species were recorded for the first time in Croatia while 15 species were not previously recorded in Dinaric western Balkan ecoregion. Based on the mayfly assemblage, sampling sites were first structured by ecoregion and then by habitat type. In comparison with the surrounding countries, the Croatian mayfly fauna is the most similar to the Hungarian and Bosnian fauna. Some morphologically interesting taxa such as Baetis cf. nubecularis Eaton, 1898 and Rhithrogena from the diaphana group were recorded. Ephemera cf. parnassiana Demoulin, 1958, the species previously recorded only from Greece, was also recorded.

Aquatic Macroinvertebrates of the Sava River

The objective of this chapter is to present the data on aquatic macroinvertebrate communities along the Sava River, based on investigation performed during 2011 and 2012 at 12 sampling sites within the sector between Vrhovo (Slovenia) and Belgrade (confluence to the Danube). During our study 227 macroinvertebrate taxa were recorded in the Sava River. Having in mind that upper stretch of the Sava River was not covered by this work (alpine and subalpine stretch), as well as based on the review of previous works on the macroinvertebrate fauna of the Sava River, more than 300 species will be confirmed for the Sava River. The data on the distribution of aquatic macroinvertebrates revealed five different stretches—alpine, subalpine, Upper Sava plain, Middle Sava and Lower Sava. Physical habitat degradation, pollution and pressure caused by biological invasions were found to be the main factors of endangerment of aquatic macroinvertebrate fauna diversity. There is an obvious need for further investigation of the Sava River in order to complete the data on aquatic macroinvertebrates and to provide the basis for accurate assessment of environmental status of the river.

Spatial distribution and seasonal changes of mayflies (Insecta, Ephemeroptera) in a Western Balkan peat bog

Abstract Peat bogs are unique wetland ecosystems of high conservation value all over the world, yet data on the macroinvertebrates (including mayfly assemblages) in these habitats are still scarce. Over the course of one growing season, mayfly assemblages were sampled each month, along with other macroinvertebrates, in the largest and oldest Croatian peat bog and an adjacent stream. In total, ten mayfly species were recorded: two species in low abundance in the peat bog, and nine species in significantly higher abundance in the stream. Low species richness and abundance in the peat bog were most likely related to the harsh environmental conditions and mayfly habitat preferences. In comparison, due to the more favourable habitat conditions, higher species richness and abundance were observed in the nearby stream. Three of the recorded species, Caenis luctuosa from the peat bog, and Eurylophella karelica and Leptophlebia marginata from the stream are new records for the Croatian mayfly fauna. Typical Central European life cycle patterns were confirmed for several species (e.g. Baetis vernus, Nigrobaetis niger, Electrogena ujhelyii), while for several others (e.g. Habrophlebia fusca, Paraleptophlebia submarginata) some discrepancies were observed. Therefore, these results provide new and valuable information on the ecology of mayflies in peat bog habitats.

Novi nalaz razmnožavanja vrste Lindenia tetraphylla (Vander Linden, 1825) (Odonata, Gomphidae) na sjeverozapadnoj granici njene rasprostranjenosti

A total of 12 dragonfly species were recorded at Vlačine Reservoir in the Dinaric Western Balkan region (ER 5) in Croatia. Habitat conditions, i.e. vegetation structure and physico-chemical water properties of the reservoir, are presented and discussed. Habitat conditions were suitable for life cycle completion of Mediterranean species such as Lindenia tetraphylla and Selysiothemis nigra. Exuviae of L. tetraphylla represent new evidence of the species’ reproduction in the north-western border of its distribution

Alderfly assemblages (Megaloptera, Sialidae) along an oligotrophic karst hydrosystem: spatial patterns and species-environment relationship

Even though alderflies, as well as many other aquatic macroinvertebrates, are widely used as indicators of freshwater quality, the knowledge of their distribution, biology and ecology in karst freshwater habitats is still very scarce. Aiming to fill this gap, we investigated alderfly assemblages along an oligotrophic karst hydrosystem. Sampling was carried out on a monthly basis over a one-year period (2007/2008) in different types of freshwater habitats and microhabitats. Our goals were to determine population aspects, habitat and microhabitat preferences of alderflies as well as their relation to environmental factors. Due to the specificity of karst freshwater habitats, alderflies were rather rare in the studied hydrosystem. Yet, their fauna was diverse with four identified species, where Sialis fuliginosa Pictet, 1836 was the most widespread one. Sialis sordida (Klingstedt, 1932) was recorded for the first time in the Balkan Peninsula being the rarest species in our study. Substrate type and water velocity showed as key environmental parameters in determining alderfly assemblages. Alderflies were mostly recorded from a canyon type mountainous stream, and silt with leaf litter, respectively. They were not recorded at sites characterized by predominately solid stones (i.e. cobbles) and mosses, and with intermittent water flow. Our results strongly indicate that alderflies could be used in future conservation and protection management procedures in karst freshwater habitats.