I give an overview of the first two records of black jetbead (Rhodotypos scandens) (Rosaceae, Magnoliopsida), a native of East Asia, in Austria. The species is locally established in a deciduous forest in the eastern lowlands of Austria c. 10 km north of Vienna. The population consists of c. 1,000–2,000 specimens distributed over an area of c. 2.5 ha. The composition of the invaded vegetation has been documented by three relevés. In addition, an escaped population of 17 young specimens of Rhodotypos scandens is recorded from Vienna. Rhodotypos scandens is widely naturalized in forests of the eastern USA, where it is considered to be invasive. Recently, in several Central European countries escaped populations of Rhodotypos scandens have been documented. Thus, the future spread of this species in Europe should be monitored.

Ehrharta erecta (Poaceae, Ehrhartoideae) is a neophyte native to South Africa and it is considered as one of the most invasive plant species in the world. The aim of the present work, based on bibliographic, herbarium and in the field researches, is to update the distribution of Ehrharta erecta in Italy. As long as the present researches were carried out, we eventually discovered the first population of the species in Sicily. Notes on taxonomy, relations with Ehrharta delicatula, features of the environment in which it was found and the status of naturalization of the species are here presented and discussed.

The presence of a freshwater red alga (Rhodophyta), Compsopogon caeruleus, was recorded for the first time in the High Paraná River. It was detected in 2016 and 2017 at five points along 290 km of the border between Argentina and Paraguay. High densities of filaments of the red alga were recorded in the summer months, forming masses flowing through the middle of the riverbed and banks, and not recorded in the main body of the Yacyretá Binational Reservoir (Argentina-Paraguay). We identified the species both morphologically and using molecular methods. The samples were characterized by having short, thorn-like branches, which resembled the morphology reported for Compsopogon aeruginosus, nowadays a synonym of C. caeruleus. Partial DNA sequences from cytochrome c oxidase subunit I gene confirmed species identification as C. caeruleus. Because of its adaptability to a wide range of environmental conditions, we speculate that the species could establish in the High Paraná River and potentially rapidly increase its distribution downstream throughout temperate regions of South America.

Brachymyrmex cordemoyi Forel, 1985 is a small ant species native to the Neotropics, but it has been introduced into Africa, Madagascar, the Arabian Peninsula and some tropical oceanic islands. We report on a non-native Brachymyrmex population that has been discovered indoors in the vicinity of Euskirchen (Germany). Specimens were identified morphologically and subjected to DNA barcoding; molecular data of the new population was analyzed jointly with morphologically verified GenBank entries. Morphological identification and phylogenetic inference based on a fragment of the mitochondrial gene Cytochrome Oxidase subunit 1 gave congruent results. The population was clearly assigned to B. cordemoyi and represents the second report of this species from Europe, with a recent record from the Netherlands. In Germany the species has only been found indoors, and the here reported population has been exterminated. This new record represents one of many indoor introductions of the genus Brachymyrmex, likely via tropical plants. We present a diagnosis of the species and additionally review all known introductions of the genus which have been identified to the species level.

The honey bee, Apis mellifera, is a non-native species in America that has great economic importance for crop pollination and honey exports but also is a strong competitor for the native bees. Wild colonies of honey bees may particularly impact the native bee fauna on islands negatively by competing for limited nectar and pollen resources. The southern islands of the Gulf of California were surveyed in 2018 in the most recent scientific expedition since the last one made in 1921. The presence of honey bees was recorded in twelve of fourteen sampled islands for the first time. These new records should encourage further surveys and monitoring, in order to detect if honey bees already have established viable colonies or if they are transient visitors.

We utilized a social media website (Facebook) to gather information from citizen scientists on their observations of the introduced large land snail species Cornu aspersum, and Helix lucorum in Budapest, Hungary. In a Facebook post we presented the project to reveal where the two species occur in Budapest, together with an identification guide which included images. In this study we compiled information received in the two months following the Facebook post. We obtained 44, 92 and 105 locality observations of H. lucorum, the native H. pomatia and C. aspersum, respectively in the city, mostly within five days after the post. Our Realtime Social Networking Service (RSNS) method, which included intensive communication with citizen scientists, revealed that C. aspersum was spread in most areas across Budapest, except for the Buda region west of the Danube where H. lucorum dominates. Their distributions overlapped with each other only in small ranges. We found that no specimens of these non-indigenous species were present in the collection of L. Drimmer, who extensively collected land snails in the city in the early 1990s. Accordingly, the two non-indigenous species most probably established their current distributions in Budapest in the last 30 years. Our study demonstrates that RSNS method efficiently and rapidly reveals distributions of relatively large animal species in city areas and provides a dependable basis for further research.

The viviparid snails, Cipangopaludina chinensis (Chinese mystery snail) and Cipangopaludina japonica (Japanese mystery snail) are considered high priority invasive species on the east coast of the United States. Both species are often lumped together with other related gastropods into the broad group known as the Asian “mystery snails”. In New York, there has been conflicting reports on the presence of C. japonica with only a single population ever recorded in the southern region of the state in the early 1980s. This confusion has been attributed to the lack of distinguishing conchological features between both species. To address this issue, we employed molecular barcoding to determine whether C. japonica was indeed present in the state’s waterways. Specimens were collected from multiple waterbodies in the Adirondack region of northern New York during the summers of 2016–2018. In addition, museum specimens from the type locality (Japan) and North Korea were acquired and initial conchological identifications were carried out prior to barcoding. Conchological comparisons found that both species were virtually indistinguishable from each other. Although C. japonica appeared to have a slightly more elongated spire than C. chinensis, this trait still appeared to be highly plastic even within C. japonica. Regardless, molecular barcoding using the cytochrome c oxidase I (COI) gene unequivocally confirmed the identity of C. japonica with both sequenced specimens showing a 100% identity match on the NCBI database, GenBank. Furthermore, both species clustered within separate and well supported clades with K2P interspecific genetic distances of 0.13–0.15 and intraspecific distances of 0.00–0.01. This study is the first to genetically confirm C. japonica from the Adirondack Park and to a broader extent New York and also re-emphasizes the utility of barcoding techniques for aquatic invasive species (AIS) detection.

This paper presents new records of P. antipodarum in inland waters of Lithuania, along with its distribution patterns in the country and within particular lakes. In the period 2014–2018, seven new records sites were found. The current distribution pattern of the snail suggests secondary dispersion vectors are accelerating the spread of the species between distant ecosystems. It was found that most initial records of the invader were in parts of the lakes with intensive water recreation activities. Additionally, analysis at the level of individual lakes indicated high population densities (on average (± SD) from 106.7 ± 45 to 1966.7 ± 1315.8 ind. m^-2) in the parts of lakes with recreation activities, thereafter decreasing to zero with distance from these sites. Such results imply the possible role of overland movement of watercraft in the rapid dispersion of P. antipodarum over considerable distances.

The mollusc Diodora ruppellii (G. B. Sowerby I, 1835) (Gastropoda: Lepetellida: Fissurellidae) is reported here for the first time as an alien species in Libyan coastal waters. Field surveys conducted throughout the winter period of 2018–2019 along the sandy shoreline bordering Tripoli Harbour yielded fourteen empty shells and one live specimen, all found within accumulating shell middens. While the finding of D. ruppellii in close proximity to Tripoli Harbour may allude to its introduction via shipping traffic, natural dispersal from nearby, known or yet undiscovered, Mediterranean populations cannot be ruled out. The current study forms part of a larger ongoing programme investigating the marine fauna of the littoral zone with a focus on the identification of non-native species. As D. ruppellii is so far recorded from Libya as based on the present punctiform record, we rank it here as a casual (i.e. not established) species in the country.

During the SIBES project, a large-scale monitoring of the marine benthos of the Dutch and western German Wadden Sea, three specimens of the bivalve Mulinia lateralis (Say, 1822) (Bivalvia: Mollusca: Mactridae), a common opportunistic species native in the east coast of North America, were found in August 2017 in the Ems-Dollard estuary. Present records backdate of two months the arrival of this species in Europe and first report it for the German Wadden Sea. Further specimens were then found in 2018, confirming its establishment in the area. An analysis of favourable habitat characteristics for M. lateralis showed that large parts of the Dutch Wadden Sea are a potential suitable habitat for this species.

The invasive tropical American brackish water mussel Mytella strigata is recorded for the first time from the Indian sub-continent and this is the fourth report from the Indo-Pacific. The mussels were found attached in high densities (120 ± 24 ind. 25 cm^-2) to floating plastic bottles, wooden pilings, walls of fish cages, hulls of boats and bottom sediment in the Cochin backwater, Kerala, India during summer 2019. The only other bivalve species found with this population was Perna viridis. The mean length to height ratio for the Cochin population of M. strigata was 2.06 ± 0.26 cm with the largest individual having a length of 5.9 cm. The general external colour of the shells in Cochin population was uniformly black when wet but they exhibit dark green over the dorsal and posterior areas with faint paler streaks when dry. In addition some of the individuals rarely form bright green colour and pattern as seen in Singapore populations. The mitochondrial DNA cytochrome c oxidase subunit I gene sequences of mussels from this study were consistent with specimens in their native range, from Colombia, and from Singapore where it has recently been reported as invasive. The invasion of this species in Cochin may be through ballast water or fouling on ships hulls from its native range or from Singapore where it has been established recently. Their rapid growth, early maturity and wide salinity tolerance make them a potentially alarming fouling species in all brackish waters of India and neighbouring countries.

An inspection was carried out at shrimp farms located South West of Lake Maracaibo (Zulia State, Venezuela), with high incidences of mussel bivalve. Morphological and genetic analysis helped to identify the species as the dark false mussel Mytilopsis leucophaeata Conrad, 1831, and this is the first record of the species from tropical waters of northern South America. The highest incidences of mussels were detected in ponds and channels but no live mussels were observed in the coastal intertidal area surrounding the entrances of the farms, although empty shells were detected there, suggesting their former presence. The environmental conditions of the artificial system of shrimp culture, is a niche suitable for the proliferation of the bivalve. The consequences of the presence of this bivalve in the production of shrimp are discussed.

Laticorophium baconi (Amphipoda, Corophiidae) was recorded for the first time in European marine waters from buoy fouling communities at the Sant Carles de la Ràpita marina (Alfacs Bay, Eastern Mediterranean Spanish coast). Presence of juveniles, adult males, brooding and ovigerous females were indicative of a well-established population. An entire description of the species, together with a dichotomous key to Corophiini genera characterized by urosome segments fused with uropod 1 ventrally inserted, are provided. This record supports the view that L. baconi may have been overlooked and/or potentially confused with other Corophiini species such as Apocorophium acutum in previous studies.

The paper provides a new record of the North-American invasive amphipod Gammarus tigrinus from the Bornholm island (Denmark), accompanied by DNA barcodes. We found this species in two locations 9 km apart: 1. Baltic Sea in Svaneke, 2. Østersøen stream, Nexø. Our finding shows further range expansion of this species in the Baltic Sea. Earlier findings of this invader from Germany (1985), Poland (1988), Lithuania (2004), Latvia (2011), Estonia (2003), Finland (2003) and Russia (2005). However, taking into account, the current locality, spreading directions and speed it is only a matter of time, before the species colonizes coastal waters all around the Baltic Sea and its islands.

Five specimens of Penaeus aztecus was caught from the Turkish waters of the Aegean Sea and one specimen was caught from the Turkish waters of the Middle Black Sea, Turkey. The current paper reports a new location for the Aegean Sea. Within approximately eight years, the species has been recorded from the southeastern Levant to the Gulf of Lion, the Aegean Sea, and finally from the Black Sea. This is the first report of the species from the Black Sea. Presumably, the species migrated to the Black Sea by swimming through the Turkish Strait System.

After reaching the Italian and Spanish coasts of the Western Mediterranean Sea, the American blue crab Callinectes sapidus was finally observed on the French coasts. To date, it has been caught in eleven lagoons and three sites of the French coast. Its strong invasion capacities will probably lead to important changes in the structure and composition of French lagoon biota.

The redclaw crayfish, Cherax quadricarinatus (von Martens, 1868), inhabits freshwater creeks and water bodies, and is native to the tropics of Queensland and the Northern Territory in Australia, as well as south-eastern Papua New Guinea. It has been translocated to other parts of Australia and around the world, often becoming established in the wild and potentially having negative impacts in invaded ecosystems. In north-western Australia, which lacks native crayfish, this species is known from the Ord River system in the Kimberley Region and from a water supply reservoir, Harding Dam, in the Pilbara region. Following a report of their presence in another area of the Pilbara region, Karijini National Park, a rapid assessment of crayfish occurrence was undertaken in and around Karijini and Millstream-Chichester National Parks. Redclaw crayfish were found at the known site within Karijini National Park and at a river pool west of the park. They were also detected in George River within Millstream-Chichester National Park. A separate baseline aquatic fauna survey, undertaken later as part of a mining environmental impact assessment, also recorded populations of the species in a tributary of the Fortescue River, located between these parks. The survey suggests that redclaw presence is associated with significant reorganisation of faunal and floral assemblages of river pools. With the new records presented here, the redclaw crayfish is now known from four catchments in the Pilbara Region, spread across three of the region’s five drainage basins. Management options for this alien species are limited in this remote area, but would require further surveys to better understand their current distribution and dispersion capability, setting up public education campaigns and targeted control measures to minimise their spread to new catchments and their impact on high conservation value aquatic ecosystems.

It has been ten years since the last comprehensive assessment of non-native marine fishes in Florida. Herein, we report sightings of 41 species from Florida coastal waters since the earliest reported sighting in 1984. Information is provided on the population status of each species (e.g., established, eradicated, unknown), and our early detection/rapid response program to remove these fish is described. Of the 41 species, five have established reproducing populations. Nineteen species are either eradicated or failed, while the status of 17 additional species is unknown. Since 1999, 18 individuals comprising 13 species have been removed from coastal waters, most of which were collected through our early-detection/rapid-response program. Many of those fishes were transferred to public aquaria where they were displayed to provide educational information to the public. Most reports of non-native marine fishes originated from citizen scientists, emphasizing the importance of outreach and education.

The Indo-Pacific mangrove red snapper Lutjanus argentimaculatus (Forsskål, 1775) (Chordata: Actinopterygii: Perciformes: Lutjanidae) is an alien fish that has recently invaded the eastern Mediterranean Sea, with records from Israel, Lebanon, and Turkey. We here first report the presence of this species in Greece based on three specimens spearfished between July and August 2019; they also represent the westernmost observations of the species in the Mediterranean basin up to date. After a long period of latency, this taxon seems to undergo a very rapid expansion. The likely presence of an established population in the eastern part of the Mediterranean is discussed.

This is the first report of Montague’s blenny (Coryphoblennius galerita (L., 1758) (Actinopterygii: Blenniidae) from the Gulf of Odessa, Black Sea, Ukraine. Previous records of this species were restricted to the Eastern Crimean and Turkish coasts. Three male fish of approximately the same size, all with spawning coloration, were found in October 2018. The morphology of the found fish was typical for the representatives of this species. However, the crest morphology indicated that the specimens from the Gulf of Odessa were morphologically closer to the Atlantic populations (i.e., a crest covered by small filaments along the entire margin), than to the Mediterranean ones (i.e., a crest with filaments limited to the top margin of the crest). Although the salinity during the sampling period was between 15 and 17‰, this region can experience salinities as low as 5‰. Continued monitoring of this location is needed to confirm that C. galerita forms a self-sustaining population in these lower salinity waters.

We report new distribution data on four recently introduced species in the Guadalquivir River basin: chameleon cichlid (Australoheros facetus Jenyns, 1842), North American black bullhead (Ameiurus melas Rafinesque, 1820), European catfish (Silurus glanis Linnaeus, 1758) and a minnow species of unknown origin (Phoxinus spp.). A compilation of records is used to update the distribution range of these species. The information collected reinforces the evidence on the establishment and expansion of these non-native species. We recommend new field sampling to identify the dispersal pathways and to clarify their current statuses.

Two mosquitofishes, the western, Gambusia affinis (Baird and Girard, 1853) and eastern, G. holbrooki Girard, 1859, species, were treated as a single lineage from 1882 to 1988. Here, we assess whether the mosquitofish introduced into Taiwan in 1911 for mosquito control really was G. affinis, as documented, or G. holbrooki or a combination of both. Using mitochondrial cytochrome b as a genetic marker, we sequenced 78 mosquitofish specimens sampled from around Taiwan and found only one haplotype. Our phylogenetic analyses support that only the western mosquitofish (G. affinis) has invaded Taiwan. However, since G. holbrooki is present in the Taiwanese aquarium market, future invasion by the eastern mosquitofish is very likely.

American bullfrog Rana catesbeiana Shaw, 1802 (= Lithobates catesbeianus) is one of the world’s most problematic amphibians. In both 1957 and 1973, the species was introduced to the Republic of Korea, in order to be bred as a food resource. However, after breeding efforts failed, the breeders illegally released the frogs into the wild. Now, about 50 years later, the species is distributed throughout the nation. The aim of our study was to document the distribution of R. catesbeiana throughout the Republic of Korea by analyzing several nationwide surveys. The species was reported to occur at 2,716 sites, mainly along the southern and western coasts, but was rarely distributed in the northern part of Korea or along the eastern coast. Further studies are needed to elucidate the effect of R. catesbeiana on the native ecosystems.

The Red-vented Bulbul Pycnonotus cafer (Linnaeus, 1766) is an Asian bird species classified as one of the hundred most invasive species in the world. The breeding of the species (adults feeding the fledglings) was observed in 2018 in Costa Calma (Fuerteventura, Canary Islands, Macaronesia). This is the first breeding record for Europe of this species. The first observation of the species was made in Corralejo (Fuerteventura) in 2003. In the period 2013–2018, an important range expansion of the species was recorded in Fuerteventura. In 2018, the species was also recorded in Valencia (Spain) for the first time.