Three alien macrophytes, Ascophyllum nodosum, Colpomenia peregrina and Polysiphonia morrowii, are reported for the first time from the Mar Piccolo of Taranto (southern Italy, Mediterranean Sea). Two other species, Agardhiella subulata and Codium fragile subsp. fragile that were not, or were sporadically, detected in the basin since their first record in 1987 and 2002, respectively, were also recorded. In the Mar Piccolo, there appears to be a close link between establishment of alien species and the regular import of shellfish for direct sale. To limit the flow of accidental species introductions, a continuous and rigorous control of all the economic activities performed along the coast is recommended through the enforcement of effective laws and an early detection of new introductions.

A DNA-barcode-based bio-inventory of macroalgae and macro-invertebrates in Sam Orr’s Pond, New Brunswick, was completed as part of the Canadian Barcode of Life Network’s efforts to generate a comprehensive comparative DNA database (BOLD) for rapid species identification. During an early sampling episode the invasive species Codium fragile was identified and subsequently confirmed with tufA sequence data – the first record of this species in the Bay of Fundy. An unidentified sea anemone was also collected, but COI-5P data failed to find a match in current databases (BOLD and GenBank). Subsequent morphological identification resulted in the first Canadian records for Diadumene lineata. Our discoveries highlight the importance of ongoing field monitoring, trained taxonomic expertise and comprehensive DNA barcode libraries in global efforts to track the spread of introduced species.

In the winter months of 2012 and 2013 aggregations of the native comb jelly Beroe cucumis were observed and photographed along the Israeli coast preying on the invasive American comb jelly Mnemiopsis leidyi. It is suggested that native beroid may take part in controlling populations of the invasive ctenophore.

Eight specimens of phreodrilid oligochaetes belonging to the genus Insulodrilus were found in intertidal sediment in the upper Thames estuary (Wandsworth, London) in November 2012. This is the first confirmed record of Insulodrilus in the northern hemisphere, although immature specimens previously collected in Northern Ireland may belong in this genus.

The Eastern Asian ectoparasitic copepod Neoergasilus japonicus (Harada, 1930) is a widely spread species with a high prevalence on many freshwater teleosts. It was recorded for the first time in Europe 45 years ago and continued its invasion to new geographic regions. Its presence in North America was first detected in 1993, followed by only two other continental records. In this work we present an illustrated record of N. japonicus from plankton samples collected during 1990 in a microreservoir of central Mexico. We confirm that this parasitic copepod was already present in continental America at least 3 years before previously known. This is the third published record of this Asian copepod in the Neotropical region. Its occurrence in Mexico is attributed to different events of introduction by human agency. This report supports the notion that N. japonicus is more widespread in Middle America than previously thought and it is intended to aid in the historical monitoring of the invasion of this species.

This is the first report of the occurrence of three invasive species in Colorado, USA: the water flea, Daphnia lumholtzi (G. O. Sars, 1885); calanoid copepod, Eurytemora affinis (Poppe, 1880); and a freshwater bryozoan, Lophopodella carteri (Hyatt, 1865). Analysis of monthly plankton samples taken in the Pueblo Reservoir from 2008–2010 shows recurring presence of D. lumholtzi and E. affinis, indicating range extension and establishment of the two zooplankters; L. carteri was collected in abundance in 2008 suggesting its success in the reservoir. These findings could be invaluable for determining long-term implications and management decisions pertaining to the three invasive species.

The Asiatic isopod Paranthura japonica Richardson, 1909 was collected in 2007 in Arcachon Bay (SW France), where the species occurs in a variety of habitats, both in the intertidal and at shallow depths. This species, native to the Sea of Japan, may have been accidentally introduced in Arcachon Bay with oyster transfers or as fouling on ship hulls.

The spiny-cheek crayfish Orconectes limosus was registered for the first time in the Neman River and its tributaries, in the Grodno region, Belarus in 1997. The crayfish spread upstream from Grodno over the next 14 years, migrating 177 km along the course of the Neman River. Today spiny-cheek crayfish are recorded in 8 rivers including the Neman, Narew and Western Bug basins. We never found native crayfish species together with spiny-cheek crayfish during our surveys, which may indicate replacement of native species by invasive O. limosus in the studied area.

Invasive crayfish have attracted much attention by scientists and policy makers in Europe, partly due to their ability to transmit diseases to native crayfish species. In December 2012, 13 specimens of a new crayfish species were found in the River Märstaån in central Sweden. Mitochondrial DNA analyses identified them as Marmorkrebs Procambarus fallax f. virginalis. It is not known if Marmorkrebs can establish reproducing populations in Sweden, and knowledge of how different stressors negatively affect the eventual reproduction of Marmorkrebs is lacking. Since the parthenogenetic Marmorkrebs has potential to become an invasive species in Sweden and Scandinavia, it may pose a serious threat to native crayfish, fish and fisheries. Swedish authorities have produced an action plan with a national strategy in order to establish a system that manages the import, movement and release of alien species and genotypes. The River Märstaån leads to Lake Mälaren, without barriers, which enhances the risk that the crayfish will also invade the lake. Due to the potential threat of further spread, it is imperative to make an action plan with a risk assessment targeted specifically towards the Marmorkrebs in River Märstaån.

Percnon gibbesi (H. Milne Edwards, 1853) (Decapoda, Plagusiidae) and Aplysia dactylomela Rang, 1828 (Opistobranchia, Aplysiidae) are reported for the first time from shallow coastal waters between Pounta and Elafonisos village (Laconia, Greece). The occurrence of the crab unsurprisingly bridges findings from Antikithyra Island to the south and the Mani coast to the west, while the presence of the sea hare links records from the Messinian Gulf, Paros Island, and western Crete.

Urban stormwater ponds in Singapore are interspaced among the industrial and residential areas of this highly urbanized country and represent potentially harsh artificial habitats in which freshwater fish communities might be limited to low numbers of just a few hardy species. A recent first-time survey of three large urban ponds in Singapore, however, revealed that the fish communities in these ponds are greater in density and species richness than expected, with a combined richness of 24 species and fish densities ranging from 0.26 to 306.04 fish Ha-1. These fish communities consisted of only alien species, with the dominant species being Amphilophus citrinellus. The connectivity of urban stormwater ponds to other freshwater systems in Singapore, including protected catchments with natural stream and swamp habitats that are refuges for native species, could make these habitats hotspots and beachheads for the invasion or spread of alien freshwater fish. This is a cause for concern and raises the need for more stringent regulatory controls of fish releases into these ponds.

The croaking gourami, Trichopsis vittata, is documented from wetland habitats in southern Florida. This species was previously recorded from the same area over 15 years ago, but was considered extirpated. The rediscovery of a reproducing population of this species highlights the dearth of information available regarding the dozens of non-native fishes in Florida, as well as the need for additional research and monitoring.

Specimens of the South American suckermouth armored catfish genus Pterygoplichthys were recently (2011-2012) collected in inland waters of Israel, namely, Lake Kinneret (Sea of Galilee) and Nahal Amal ("Amal Stream"). Based mainly on color patterns, at least two different species, P. disjunctivus and P. pardalis, are included but there is a possibility that the wild populations are hybrids. These collections represent the first records of this genus in Israel. The source of these non-native catfish has not been confirmed; however, the presence of these species is likely the result of either aquarium release or escape from a fish hatchery that operated previously on the shores of Nahal Amal.

A single specimen of dogtooth grouper Epinephelus caninus Valenciennes, 1834 (Perciformes, Serranidae) was captured along the southwest Crimean Peninsula, in the Black Sea. It was captured by using a trap-net at a depth 40 m, on 26 April 2013. This is the first record of Epinephelus genus in the Black Sea.