The Balkan Peninsula is a biodiversity hotspot and hosts numerous mountain lakes, which offer a refuge for a multitude of species. However, previous pristine habitats have been deeply affected by anthropogenic change, such as non-native fish introductions, which calls for multi-species considerations in the last remaining unaltered habitats. We carried out abiotic measurements and biodiversity assessments in two neighbouring alpine lakes, Lakes Leqinat and Drelaj in the Bjeshkët e Nemuna National Park in Kosovo, in August 2018. Lake Leqinat is a permanent, stratified water body and exhibits weak oxygen depletion below 3 m. Phytoplankton was dominated by chrysophycean, cryptophycean and chlorophycean algae. Zooplankton consisted of five rotifer species and Daphnia longispina. A mark-recapture experiment yielded a population of alpine newts (Ichthyosaura alpestris) of nearly 4 000 adult individuals. In contrast, cold water from the surrounding karst seeps into Lake Drelaj, which is a well-oxygenated temporary lake. Hence phytoplankton and zooplankton biomasses were considerably lower than in Lake Leqinat. Phytoplankton was dominated by cryptophycean, chlorophycean, and bacillariophycean algae. Zooplankton consisted of the diaptomid copepod Mixodiaptomus tatricus, the cladoceran Daphnia rosea, and the anostracan Chirocephalus diaphanus. Conservation efforts should ensure that Lake Leqinat remains unstocked as introduced fish would probably destroy the natural community. Research eco.mont – Volume 13, Number 1, January 2021 ISSN 2073-106X pr int vers ion – ISSN 2073-1558 onl ine vers ion: ht tp://epub.oeaw.ac.at/eco.mont ht tps://dx.doi.org/10.1553/eco.mont-13-1s12 12
Large branchiopods are one of the most iconic species groups in temporary pools. Due to their specific biology and massive habitat degradation, they are one of the most threatened freshwater species groups. In this study, we used a unique dataset on the distribution of large branchiopods on a national scale (Austria), data on the distribution of temporary pools, and environmental variables to model the potential distribution of seven large branchiopod species. For species distribution modeling, we used six predictors which were assumed to be potentially relevant for explaining large branchiopod distribution. We used three modeling techniques (Generalized Linear Models, General Boosted Models, Random Forests) for distribution modeling. While some predictors (e.g. mean annual temperature, mean annual precipitation and the proportion of arable land at the temporary pool) were important for all target species, the importance of the other variables (size of the temporary pool, connectivity, flooding probability) was variable among species, and partly also between the three model techniques used. The resulting ensemble distribution maps, which are based on ensemble models of the above-mentioned modeling techniques, show the distribution of occurrence probabilities for the modeled species. These maps can serve as a baseline for future surveying regions that have been under-sampled so far. Furthermore, as these maps identify regions where large branchiopods likely do occur, conservation measures can be prioritized towards these regions. Finally, we discuss conservation measures which should improve land use by farmers to appropriately protect large branchiopods and their habitats, temporary pools.
The present study is the first to investigate the relationships between a multiple set of paranormal beliefs and the acceptance of evolution, creationism, and intelligent design, respectively, in Europe. Using a questionnaire, 2,129 students at secondary schools in Vienna (Austria) answered the 26 statements of the Revised Paranormal Belief Scale (R-PBS) and three statements about naturalistic evolution, creationism and intelligent design (ID). The investigated Austrian students showed an average R-PBS score of 82.08, more than 50% of them agreed with naturalistic evolution, 28% with creationism, and more than a third agreed with ID, the latter two closely correlated with each other. Females generally showed higher belief scores in the paranormal, creationism and ID. The agreement with naturalistic evolution correlated negatively with religious belief, but not with other paranormal beliefs, whereas the two non-scientific alternatives to evolution significantly correlated with both traditional and paranormal beliefs. Religious belief showed a significant positive correlation with other paranormal beliefs. All subscales of paranormal belief decreased during the eight grades of secondary school, as did acceptance of creationism and ID. However, the acceptance of naturalistic evolution did not correlate with age or grade. Possible reasons and implications for science education and the biology curriculum at Austrian secondary schools are discussed.
In a blind and randomised study, early postlarval stages of the tadpole shrimp Triops cancriformis, the fairy shrimp Branchipus schaefferi, and the clam shrimp Leptestheria dahalacensis were exposed to different concentrations of a commonly available Bti suspension, equivalent to 0, 4.5 (recommended treatment concentration), 45, 450, and 4500 AA/l. No statistically significant correlations were found between Bti concentration and mortality or longevity of the ex- amined organisms.
Six different pH ranges were tested for the hatching rate of Triops cancriformis cysts. Cumulative hatching numbers approach to approximately 50% of cysts. The highest hatching rates, co-occurring with the shortest hatching times, were recorded in the neutral range. No hatching took place at pH values 9 and above. This corresponds with the most frequent habitats of this species, snowmelt pools of river flood plains as well as aestival pools caused by heavy rainfalls. Occurrences in sodic alkaline pans can be explained by relatively low pH values at the time of inundation.
Branchiopods reproductive mechanisms range from gonochorism to unisexuality, passing through androdioecy. In order to contribute to still lacking or controversial basic knowledges, we analyzed the karyotype of the main Italian taxa: the Notostracan living fossils Triops cancriformis (parthenogenetic) and Lepidurus apus lubbocki (bisexual), and the Conchostracan Eoleptestberia ticinensis (bisexual). Also one male obtained from a supposedly hermaphroditic Austrian population of T cancriformis was checked. In T cancriformis a diploid number of 12 chromosomes is observed in both females and male; this is in line with previous results on other Italian populations, but contrasts with observations on European samples. The richness of normal meiotic pictures indicates that the male specimen is able to produce sperms. L. apus lubbocki shows a diploid number of 10 chromosomes; in male specimens the mispairings during meiosis I could explain the haploid number of 6 chromosomes obtained from diakinetic plates in Palestinian samples of the same subspecies found in literature. Irregular meiotic divisions also highlight the ultrastructurally observed abortive spermatogenesis. Finally, in the presently analyzed population of E. ticinensis, the adult females show 10 chromosomes as diploid number, while males present 10 or 11 elements; in the nauplii, chromosome numbers range from 8 to 12, differing among unrelated individuals, between nauplii produced by the same female and even within the same nauplius. B elements are taken into account.
. Recent reports of occasional males in Austrian populations of Triops cancriformis have promoted interest in an analysis of the ultrastructure of the male gonad. It appears as a double thick and well-defined tubular structure running along the midgut, inside the hemocoel. It is composed of two portions: the wall and the lumen. The former is made up of germ cells that are widespread and intermixed with somatic cells. The lumen is ∼200 μm wide and acts as the collecting site of spermatids and sperm. The germ cells are recognizable by their rounded appearance and by the occurrence of exceptionally long synaptonemal complexes in their nuclei. Their maturation implies a volume elongation and an aggregation in a characteristic “cyst” arrangement. The cysts migrate towards the lumen, where they break open, releasing spermatids and sperm. At the end of this process the lumen is filled with maturing gametes. The sperm have very condensed chromatin nuclei and partially reduced cytoplasm where the most striking features are the axoneme and strewn microtubules together with evident pseudopodia. Our morphological data support the full functionality of males in T. cancriformis. However, further work on gametogenesis, distribution of sexes, and genetic analysis of breeding experiments are needed to reach a fuller understanding of the role of males in middle and northern European populations of this species.
The cyst deposition behaviour of Streptocephahis torvicarnis is described as the first documented case of active cyst deposition in Anostraca. The functional morphology of the brood pouch of S. torvicornis is described and illustrated using both Light Microscopy and Scanning Electron Microscopy. The brood pouch is an elongated tube-like structure with a subterminal crescent-shaped opening. During cyst deposition, the females insert this structure into the sediment to a depth of almost 10 mm, and deposit the resting cysts, analogous to an insect ovipositor. The opening mechanism of the genital pore is explained by contraction of a branched longitudinal muscle. The adaptive value of laying cysts into the soil and possible dispersal strategies are discussed.
For the first time, Anostraca, Notostraca and Conchostraca (Laevicaudata, Spinicaudata) will be listed in the Austrian Red Data Book of Endangered Species. According to the 1999 IUCN draft criteria, eight out of 15 large branchiopod species recorded between 1994 and 1999 are considered as critically endangered, three of which (Chirocephalus shadini, Eoleptestheria ticinensis, Streptocephalus torvicornis) occur at only one site each. Five species are considered as endangered, two of them (Branchinecta orientalis, Triops cancriformis) showing a statistically significant decrease of sites. Eubranchipus grubii and Lepidurus apus, both found abundantly mainly in the flood plains along the rivers Thaya and Morava, are near threatened. Lynceus brachyurus is extinct in Austria. Large branchiopods are mainly threatened by agricultural activities and hydrological/hydrochemical changes. Presently, three Austrian locations are protected exclusively on the basis of large branchiopod occurrence; three additional habitats are in the process of obtaining official protection. Several large populations are situated in the WWF nature reserve "March-Auen", and in the National Parks "Donau-Auen" and "Neusiedler See - Seewinkel", respectively.
This paper presents a SEM documentation of the larval development of the two most abundant Austrian conchostracan species, Imnadia yeyetta (Limnadiidae) and Leptestheria dahalacensis (Leptestheriidae). As in several previously examined spinicaudatan species, five larval stages were documented: Nauplius 1, Nauplius 2, Metanauplius, Peltatulus, and Heilophore. Additionally, three postlarval stages of L. dahalacensis and the first larval instars of Eoleptestheria ticinensis and Limnadia lenticularis are shown and compared with the examined stages. Species identification of conchostracan larval stages is possible by using surface structures, and using SEM methods, except for L. lenticularis which can be identified more easily on the characteristic shape of the labrum.
Limnadia lenticularis, a well-known representative of the Conchostraca Spinicaudata in Europe, was generally accepted as a parthenogenetic species. During an intensive faunistic study of Austrian conchostracans, four of a total of 364 collected L. lenticularis specimens were males. This paper provides the collection localities, compares the sex ratios of the five conchostracan species found in Austria, and describes the general morphology of L. lenticularis males, focussing on SEM of the male claspers.
This paper presents data on the frequency of large branchiopod associations observed in Austria in 1994 1998. Co-occurrences of two to five different species were documented. The combination of species which occurred with highest frequency were Triops cancriformis / lmnadia yeyetta, I. yeyetta / Leptestheria dahalacensis. T. cancriformis / L. dahalacensis, I. yeyetta / Limnadia lenticularis, T. cancriformis / L. lenticularis, Lepidurus apus / Eubranchipus grubii, and T. cancriformis / Branchipus schaefferi. Significant low co-occurrence indices were found fur species known to differ in phenological appearance, such as Triops cancriformis and Lepidurus apus. This species combination is known from four habitats in Europe only. Potential factors contributing to the co-occurrence of several species within apond, ecological habitat parameters, species parameters and historic factors, are listed.
In Austria, the distribution of Anostraca, Notostraca, and Conchostraca is mainly confined to the floodplains of the rivers Morava and Danube, and the shallow alkaline pans of the Seewinkel region in Burgenland province. Occasionally, large branchiopods can also be found in rain pools of the eastern and central Austrian lowlands, where topography and climate favour the existence of astatic water bodies. Differences in hydrology, temperature and water chemistry requirements may be reflected in local species compositions and species seasonal appearance. A survey conducted from 1994 through 1996 found that Chirocephalus shadini, Eubranchipusgrubii, and Lepidurus apus occurred in late winter and spring, while Branchinecta ferox, Branchinecta orientalis, Cyzicus tetracerus and Chirocephalus carnuntanus were found exclusively in spring. Streptocephalus torvicornis, Tanymastixstagnalis, and Eoleptestheria ticinensis were present in spring and summer. Branchipus schaefferi was found in summer and fall, whereas Imnadia yeyetta, Leptestheria dahalacensis, Limnadialenticularis, and Triops cancriformis occurred throughout spring, summer and fall. Streptocephalus torvicornis was documented for Austria for the first time since 1965.
According to recent literature, five of the six known Austrian ‘conchostracan’ species are extinct. However, interim results of a current study on large freshwater branchiopods in Austria show that five species still occur at a restricted number of sites in the Pannonian region of Lower Austria. The clam shrimps Leptestheria dahalacensis and Eoleptestheria ticinensis were rediscovered in May 1994 in the flood plains of the river Morava near Marchegg. Imnadia yeyetta and Cyzicus tetracerus have been known to the authors in the same region since 1981, and 1992, respectively. Limnadia lenticularis occurs in the flood plains of the rivers Morava and Danube.