The unique aquatic Pontocaspian (PC) biota of the Black Sea Basin (BSB) is in decline. The lack of detailed knowledge on the status and trends of species, populations, and communities hampers a thorough risk assessment and precludes effective conservation. This paper reviews PC biodiversity trends in the BSB (Bulgaria, Romania, Moldova, Ukraine, and Russia) using endemic mollusks as a model group. We aim to assess changes in PC habitats, community structure, and species distribution over the past century and to identify direct anthropogenic threats. The presence/absence data of target mollusk species were assembled from literature, reports, and personal observations. Pontocaspian biodiversity trends in the northwestern BSB coastal regions were established by comparing 20th‐ and 21st‐century occurrences. The direct drivers of habitat and biodiversity change were identified and documented. We found that a pronounced decline of PC species and communities is driven by (a) damming of rivers, (b) habitat modifications that disturbed previous natural salinity gradients and settings in the studied area, (c) pollution and eutrophication, (d) invasive alien species, and (e) climate change. Four out of the 10 studied regions, namely, the Danube Delta–Razim Lake system, Dniester Liman, Dnieper–Bug estuary, and Taganrog Bay–Don Delta, contain favorable ecological conditions for PC communities and still host threatened endemic PC mollusk species. Distribution data are incomplete, but the scale of deterioration of PC species and communities is evident from the assembled data, as are major direct threats. Pontocaspian biodiversity in the BSB is profoundly affected by human activities. Standardized observation and collection data as well as precise definition of PC biota and habitats are necessary for targeted conservation actions. This study will help to set the research and policy agenda required to improve data collection to accommodate effective conservation of the unique PC biota.

Until the beginning of the 21st century, the famous medicinal leech was thought to be represented by only one species, Hirudo medicinalis. However, recent publications have demonstrated that under that name, at least five different species of medicinal leeches were hidden. During the last decade, the biogeography of Western-Palaearctic leeches has begun to unravel, untangling their diversity in practically all of Europe, except for its westernmost peninsula, Iberia. Hirudo medicinalis has been repeatedly reported from Iberia, but those records were considered questionable. We discovered H. verbana in northern Spain, constituting its first record in Iberia. Using an integrative approach (combining morpho-anatomical data and molecular analyses using three genes, COI,12S rRNA, and ITS2), two endemic and geographically separated Iberian lineages have been found. One of them is easily distinguished by its distinctive colour-pattern and is described as H. verbana bilineata ssp. nov. We characterized the new subspecies morphologically, ecologically, and genetically. We also established its phylogenetic relationships with other European Hirudo spp. and confirm the presence of H. troctina in Iberia, occurring as far as 43° lat. N. Iberian H. verbana records constitute its westernmost known distribution to date. The provided distribution pattern of H. verbana contributes to a better understanding of the complexity of Iberia as a glacial refugium/cradle for endemisms, harbouring populations with a high degree of genetic structure that began to settle throughout the Pleistocene. Iberian Hirudo populations are declining in recent decades and there is an urgent need to assess their conservation status and to initiate conservation measures to reverse their decline.

Ten microsatellite loci were isolated and characterized for Stys’s bush-cricket, Isophya stysi Cejchan (Orthoptera: Tettigoniidae), an endemic Orthoptera species to the Carpathian Basin, us-ing an enriched genomic library procedure. The polymorphism of these loci were tested in two populations of I. stysi , and the number of alleles per locus varied from 4 to 16. The expected and observed heterozygosities ranged from 0.612 to 0.925 and from 0.625 to 1.000, respectively. The interspecific applicability of these microsatellites was evaluated by amplification in 20 related species: Isophya camptoxypha, Isophya sicula, Isophya ciucasi, Isophya pienensis, Isophya harzi, Isophya kraussii, Isophya zubovskii, Isophya rectipennis, Isophya modesta, Isophya longicauda-ta, Isophya dobrogensis, Isophya hospodar, Isophya speciosa, Isophya modestior, Poecilimon fussii, Poecilimon affinis, Polysarcus denticauda, Barbitistes constrictus, Leptophyes discoidalis, Phaneroptera falcata . All primer pairs for the 10 loci yielded successful amplifications in at least one other taxon from the Isophya genus. This set of microsatellite loci would be useful for genet-ic studies in I. stysi and other species of the genus Isophya .

The occurence of Dreissena bugensis (Andrusov 1897) from the Romanian Danube is reported. This represents the most westward occurrence point of quagga mussel in Europe.

The use of DNA barcoding in alien invasions has recently proved to be a powerful tool in delineating dispersal pathways and clarifying doubtful identifications. Morphological similarities between Anadara kagoshimensis (Tokunaga, 1906) and Anadara inaequivalvis (Bruguière, 1789) require the use of genetic markers in identifying the ark shell species that has recently invaded the Black Sea. The high genetic similarity (99.8-100%) hereby found between COI sequences obtained from the Black Sea samples and Japanese A. kagoshimensis confirms at a molecular level that the ark clam species invading the Romanian Black Sea belong to this taxon.

Sinanodonta woodiana (Lea, 1834) is a large Unionid species with a real invasion success. It colonized Europe, Central America, the Indonesian Islands and recently North America. The species life cycle involves a larval parasitic stage on freshwater fish species which contributes to the spread of the mussel. In this paper we describe, for the first time, eight polymorphic microsatellite loci for the species Sinanodonta woodiana. The genetic screening of individuals confirmed that all loci were highly polymorphic. The number of alleles per locus ranged from 7 to 14 and the observed heterozygosity ranged from 0.650 to 0.950. These loci should prove useful to study the species population genetics which could help to infer important aspects of the invasion process.