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Shallow lakes are strongly affected by global climate changes reflected in significant parameters of ecosystem deterioration, i.e. biodiversity decrease, and water turbidity. Zooplankton research in Škrčev kut oxbow lake (Krapina River watershed, NW Croatia, Europe) was conducted during the summer of 2012 and 2013 with the aim to determine the effect of inter-annual, short-timescale changes of hydrological regime on environmental conditions, macrophytes, zooplankton and fish assemblage within an oxbow lake in the temperate region. Within one-year period the water level increased by 2 meters. This caused a significant reduction of floating-leaved macrophytes (i.e. Nuphar lutea), while turbidity, ortho-phosphate and chlorophyll a concentrations increased. These altered ecological conditions were reflected in the shift from floating-leaved macrophytes at the lower water level to phytoplankton-dominated lake at the higher water level. Zooplankton underwent significant alteration in assemblage. The results suggest that fish preference suppressed cladocerans and enhanced the rotifer and copepod abundance. Our results indicate that even in a short-timescale zooplankton assemblage mediates in the modification of ecosystem functioning.

The research of zooplankton diversity, abundance and trophic structure was conducted during the summer period in pelagial zone on the longitudinal profile of the Sutla River Backwater. Investigated site consists of two interconnected basins: transparent Upper Basin with submerged macrophytes and turbid Lower Basin without macrophytes in the littoral zone. In the Upper Basin, abundance and diversity of zooplankton in the pelagial was higher in comparison to the Lower Basin, with prevailing species of genus Keratella as microfilter-feeder, and genera of Polyartha and Trihocerca as macrofilter-feeder rotifers. On the contrary, in the Lower Basin, crustaceans dominated in abundance. Microfilter-feeder cladoceran (Bosmina longirostris) and larval and adult stages of macrofilter-feeder copepod (Macrocyclops albidus) prevailed in the Lower Basin. Fish predation pressure was more pronounced in the pelagial of the Upper Basin, indicated by low cladoceran abundance in the surface layer. Although the studied basins were interconnected, results indicate significant (Mann-Whitney U test, p < 0.05) differences in the zooplankton structure as a potential result of the macrophyte impact on environmental conditions and fish predation pressure.

Subterranean ecosystems are among the most widespread environments on Earth, yet we still have poor knowledge of their biodiversity. To raise awareness of subterranean ecosystems, the essential services they provide, and their unique conservation challenges, 2021 and 2022 were designated International Years of Caves and Karst. As these ecosystems have traditionally been overlooked in global conservation agendas and multilateral agreements, a quantitative assessment of solution-based approaches to safeguard subterranean biota and associated habitats is timely. This assessment allows researchers and practitioners to understand the progress made and research needs in subterranean ecology and management. We conducted a systematic review of peer-reviewed and grey literature focused on subterranean ecosystems globally (terrestrial, freshwater, and saltwater systems), to quantify the available evidence-base for the effectiveness of conservation interventions. We selected 708 publications from the years 1964 to 2021 that discussed, recommended, or implemented 1,954 conservation interventions in subterranean ecosystems. We noted a steep increase in the number of studies from the 2000s while, surprisingly, the proportion of studies quantifying the impact of conservation interventions has steadily and significantly decreased in recent years. The effectiveness of 31% of conservation interventions has been tested statistically. We further highlight that 64% of the reported research occurred in the Palearctic and Nearctic biogeographic regions. Assessments of the effectiveness of conservation interventions were heavily biased towards indirect measures (monitoring and risk assessment), a limited sample of organisms (mostly arthropods and bats), and more accessible systems (terrestrial caves). Our results indicate that most conservation science in the field of subterranean biology does not apply a rigorous quantitative approach, resulting in sparse evidence for the effectiveness of interventions. This raises the important question of how to make conservation efforts more feasible to implement, cost-effective, and long-lasting. Although there is no single remedy, we propose a suite of potential solutions to focus our efforts better towards increasing statistical testing and stress the importance of standardising study reporting to facilitate meta-analytical exercises. We also provide a database summarising the available literature, which will help to build quantitative knowledge about interventions likely to yield the greatest impacts depending upon the subterranean species and habitats of interest. We view this as a starting point to shift away from the widespread tendency of recommending conservation interventions based on anecdotal and expert-based information rather than scientific evidence, without quantitatively testing their effectiveness., (© 2022 The Authors. Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge Philosophical Society.)

A review of the genus Typhloiulus Latzel, 1884 (Julida: Julidae) in the Dinaric region is given. Previously published and new faunistic records are provided for each species, together with notes for some of them. Four new species are described: T. clavatus sp. nov., T. gracilis sp. nov., T. opisthonodus sp. nov., and T. parvulus sp. nov., all from caves in Dalmatia and Herzegovina. In addition, we provide the first description of the male of T. insularis Strasser, 1938. Some taxonomic relationships among Typhloiulus species and biogeographical aspects (with distribution maps) of the genus are discussed.

Three new species of the family Anthogonidae are described from caves in Croatia and Montenegro, respectively: Egonpretneria vudutschajldi Antić & Dražina sp. n., Haasia jalzici Antić & Dražina sp. n., and Macrochaetosoma bertiscea Antić & Makarov sp. n. All three subfamilies within Anthogonidae are diagnosed, with brief discussion of relationships between genera and notes on their biogeography. A map of the global distribution of Anthogonidae is presented, as well as maps of the distribution of each species of Balkan anthogonids, including numerous new locality data. The first SEM images are provided for some representatives of this family. A key is given to all seven anthogonid genera. The subfamily Haasiinae Hoffman, 1980 is a new synonym of Anthogonidae, syn. n., while Macrochaetosoma bifurcatum Ćurčić & Makarov, 2001 becomes a new synonym for M. troglomontanum Absolon & Lang, 1933, syn. n..

Three new monotypic genera are described from underground habitats in Croatia: Balkanodesmus biokovensis gen. n., sp. n., Solentanodesmus insularis gen. n., sp. n. and Velebitodesmus cavernicolus gen. n., sp. n. In all three new genera the prefemoral part of the gonopods is orientated transversely to the main body axis, and all three new genera possess numerous metatergal setae arranged in a few transverse irregular rows, a condition observed in several European trichopolydesmids. These three new genera are very close to the genus Verhoeffodesmus. A distribution map and a brief discussion about the relationship with congeners are provided.