The cosmopolitan land planarian Bipalium kewense Moseley, 1878 (Tricladida: Geoplanidae: Bipaliinae) is recorded for first time from Cuba on the basis of specimens from the Gran Parque Natural Topes de Collantes, Sancti Spíritus province. Both external morphology and internal anatomy agree with B. kewense features. Maximum likelihood and Bayesian inference analysis of mitochondrial cytochrome c oxidase I (COI) sequences obtained from Cuban individuals form a well-supported clade with other specimens of B. kewense from Europe. This constitutes the first Cuban land planarian identified to species level based on morphological and molecular studies.

Cordylophora caspia (Pallas, 1771) colonies have significant biofouling potential at hydropower facilities, which can increase maintenance and cause system failure. In 2015, C. caspia colonies were observed at dams along the Lower Colorado River system in Lake Powell UT, Lake Mead NV/AZ, Lake Mohave AZ/NV, and Lake Havasu AZ/CA. The hydroid was serendipitously found on settlement plates deployed for invasive dreissenid mussel monitoring. Species identification was confirmed by taxonomy and molecular analysis, and phylogenetic reconstruction was performed to identify the relationship of sequenced COI fragments relative to those from C. caspia specimens collected at other geographic locations.

The northwest Pacific colonial ascidian Perophora japonica Oka, 1927 was first reported from Ireland in 2012 from Carlingford Marina and with increased frequency by 2014. Colonies were found in three additional marine inlets: Strangford Lough in 2012, Mulroy Bay in 2013, and Clew Bay in 2015. Colonies overgrew marine algae and sessile invertebrates attached to floating pontoon units supporting a marina boardwalk, and were also found on the low shore and at depths of 24 m. The species should now be considered established in Ireland. It is unknown how this ascidian arrived, but it is likely to be from elsewhere in Europe either on the hulls of vessels, with commercial oyster movements, or with drifting algae. These are currently the most northern records for the species in the north-east Atlantic, the nearest records to Ireland being from Anglesey on the north coast of Wales.

Anentome helena (von dem Busch in Philippi, 1847) is known among aquarium enthusiasts as the “assassin snail”, and is usually kept to prey on other snail species that are considered pests in home aquaria. There have been concerns that, given its prevalence in the ornamental pet trade, it is only a matter of time before this predator is introduced to the wild. We report the first occurrence of established populations of Anentome helena in a non-native habitat, and provide CO1 sequences of the species from the wild.

The Chinese mystery snail, Cipangopaludina [=Bellamya] chinensis, is documented for the first time in the Saint John River, New Brunswick, a watercourse which drains the largest watershed in Atlantic Canada. This is the first non-native mollusc known to be established in the Saint John River system. Although significant ecosystem effects of the species seem unlikely, possible introduction of C. chinensis via boat traffic emphasizes the need for boater education combined with monitoring of the Saint John River system for potentially more troublesome non-native species, including the zebra mussel, Dreissena polymorpha. Review of published records and museum collections for Atlantic Canada show C. chinensis has been reported from 13 freshwater wetlands and waterbodies in New Brunswick, Nova Scotia and Newfoundland since 1955. The species remains extant in at least 10 of these sites and is clearly more widespread in the region than the single previously published report would suggest.

Obesogammarus obesus (Sars, 1894), a Ponto-Caspian amphipod, is reported for the first time from the Netherlands in the Amsterdam–Rhine canal near Nigtevecht. In addition to the first finding in October 2012, a record of O. obesus in October 2015 from the same locality indicates that the species may have established itself in this canal. Ship-assisted transport is the most likely explanation of introduction at the site.

Two Hypophthalmichthys molitrix (silver carp) were collected in the Pearl River on 6 September 2012 during a natural fish kill in the decommissioned lock chamber of Lock-and-Dam No. 1 located at river kilometer (RKM) 47.5 in St. Tammany Parish, 9.4 km NW of the city of Pearl River, LA. Fish were a male 987 mm TL, 10.9 kg, and a female 1042 mm TL, 12.2 kg. Both fish were age 5. Eight additional silver carp (930–1054 mm TL, 9.1–14.1 kg) and one bighead carp (H. nobilis) (1065 mm TL, 15.9 kg) were collected in the West Middle Pearl River 29 September – 1 October 2015 (RKM 18.9–20.8), 10.5 km E of Slidell, LA (St. Tammany Parish). All specimens were male and ranged 6–9 years in age. A silver carp (age = 7) was collected by a recreational fisher 19 November 2015 in the Pearl River below the Ross Barnett Reservoir (RKM 480) near Jackson, MS. These three collections are believed to represent nonindigenous silver and bighead carp dispersal from the Mississippi River Basin during floods.

The rapa whelk Rapana venosa (Valenciennes, 1846) has few predators in areas outside of its native range. Here we report the first incidence of predation by a small shark Mustelus schmitti Springer, 1939 on the rapa whelk in coastal waters of Argentina. This finding could give information about possible trophic control over R. venosa as it potentially disperses into coastal waters of Atlantic South America.

Invasive populations of suckermouth catfishes (Loricariidae) are native to Central and South America, but have become established in US and Mexican waters since the 1950’s and have been reported to have negative impacts on North American freshwater ecosystems. Two genera of loricariids have been reported from Texas waters (Hypostomus spp. and Pterygoplichthys spp.), both of which have become established in aquatic ecosystems where there are warm-water refugia, or suitable and seasonally stable temperatures. In an effort to better understand the invasive dynamics of these loricariids in novel ecosystems, aspects of their reproductive biology such as fecundity, seasonality of spawning activity, and spawning frequency of the individual fish were studied for Hypostomus cf. niceforoi living in the spring-fed San Marcos River, Texas. Fecundity was similar to Hypostomus spp. in the native range. There did not appear to be any synchronicity of spawning between individual fish within the invasive population, and there was a hint in the oocyte size-frequency data that some of the fish may be spawning multiple times per year. The timing of spawning activity in the novel range was seasonally inverted compared to the pattern typical of loricariids in the native range. The season of peak reproductive activity was also less distinct in the novel range than in the native range, and the period of reproductive quiescence was more seasonally compressed than in the native range. We provide data and supporting arguments suggesting that photoperiod is the primary proximate factor triggering the onset of reproductive quiescence, as well as a return to reproductive activity for these fish in both their native and novel ranges.

An annotated checklist of non-native benthic macroinvertebrates and fish in 6 sub-basins (assessment units) of the Dnieper River is presented (based on a literature survey and the author’s unpublished data). In total, the checklist includes 92 non-native aquatic species (invertebrates – 57, fish – 35), primarily of Ponto-Caspian origin. This background information provides support for possible future development of relevant management options towards control of invasive species in the studied area, which is an important part of the European network of inland waterways and the European inland water “central invasion corridor”.