Codium fragile subsp. fragile (Suringar) Hariot is a large, dichotomously branched green alga that has invaded many temperate locations around the globe. Despite its wide distribution and pest status, there are few accounts of Codium fragile subsp. fragile that provide morphological descriptions, including illustrations, for comparison. In 2008, a seaweed sample suspected to be Codium fragile subsp. fragile was collected from Albany, Western Australia. As this taxon superficially resembles other local erect and dichotomously branching Codium species, a detailed morphological and molecular analysis of the suspect alga was conducted. Investigations confirmed the identity of this alga as the invasive subspecies Codium fragile subsp. fragile . This represents the first record of this species in Western Australia.

The present work reports the finding of an introduced annelid, Lumbriculus variegatus Müller, 1774, in freshwaters of Minas Gerais (Brazil). The Family Lumbriculidae has a Holartic distribution and in recent years was introduced in aquatic environments of Patagonia (Argentina). This is the first report of the family in Brazil. The samples were collected with a D-shaped hand-net with 250µm opening mesh between 2011 (September) and 2012 (January, April and June) in an urban stream in Poços de Caldas, southwest of the State of Minas Gerais (Brazil).

Hypania invalida is a freshwater polychaete of Ponto-Caspian origin that has recently colonised many large European rivers. Here we report the first record of this species in the territory of the Czech Republic. It was found at four sites in the Elbe River close to the Czech-German border in 2014. We presume that the most probable vector was the shipping industry.

A non-native species of the cyclopoid copepod in the genus Oithona was first recorded in the Black Sea in 2001 and was initially identified as Oithona brevicornis Giesbrecht, 1891. During the following years, this species became widely distributed first in the coastal then in the open areas of the Black Sea and later spread into the adjacent Sea of Azov through the Kerch Strait. Recent detailed re-examination of morphological features of this Oithona species indicated it is not O. brevicornis, but may be O. davisae Ferrari F.D. & Orsi, 1984 or perhaps one of the other species similar to O. brevicornis. This study examined the morphological features of this Oithona species collected from sites in the western and northeastern Black Sea, and genetic analyses were performed on specimens collected in the western Black Sea to clarify its identification. While we concluded the non-native species was not O. brevicornis or any of the native Oithona species, the lack of information on Oithona davisae in GenBank precludes definitive identification of taxonomic status. Additional genetic data are needed on O. davisae collected from its native and non-native range to allow definitive identification of specimens of this non-native species.

A survey to monitor for marine non-indigenous species in two marinas of the Archipelago of Madeira (Portugal) has detected the invasive caprellid Caprella scaura Templeton, 1836 in Madeira Island. This species was first described from Mauritius in the western Indian Ocean. During the 20th century, Caprella scaura has been detected in numerous locations worldwide (Australia, California, Mediterranean) and most recently reported in southern Europe and northern Africa. Hull fouling was the most likely vector for the introduction of C. scaura to Madeira Island.

Twenty years after its initial introduction to Europe, the Asian brush clawed crab Hemigrapsus takanoi is now a successful invader of the European Atlantic and North Sea coasts from northern Spain to southern Denmark. In July 2014, this species was recorded in the Baltic Sea for the first time, as eight individuals were found in the inner Kiel Fjord, Schleswig-Holstein, Germany. To date, a total number of 19 individuals have been collected. Findings of an ovigerous female and of juvenile crabs among the collected individuals indicate that H. takanoi most likely already reproduces successfully in the Baltic Sea.

The brush-clawed shore crab is reported from the River Medway, Kent and the River Colne, Essex, England. These represent the first records of Hemigrapsus takanoi Asakura and Watanabe, 2005 from Great Britain. If H. takanoi becomes established in GB, it may pose a threat to populations of the native shore crab Carcinus maenas.

We report the presence of blackchin tilapia, Sarotherodon melanotheron, in the coastal waters of Manila Bay and in the river tributary of Hagonoy, Bulacan, suggesting its possible range expansion. The occurrence of the native Central American Mayan cichlid, Cichlosoma urophthalmus, is also putatively confirmed for the first time in Hagonoy, Bulacan. While morphological features, morphometric characters, and meristic counts of the current populations match those reported elsewhere for these species, further genetic work is required to confirm their identification and possibly provide information on their source. Negative impacts of the existence of the two species due to competitive interactions have already been anecdotally reported, however, no empirical scientific evidence is available to provide verification. Therefore, studies on the potential ecological impacts should be done, especially because the two species were already reported as notoriously invasive.

The Asiatic weatherfish, Misgurnus anguillicaudatus, is a generalist species that has invaded numerous physiographic niches worldwide. Asiatic weatherfish populations have been observed to compete with native fish populations in Hawaii and are of major concern in Australia due to the concomitant introduction of an exotic parasite. Asiatic weatherfish populations have been observed in 16 of the contiguous United States (US) since the 1940s. Alabama is the most recent US state to report sustaining Asiatic weatherfish populations. Asiatic weatherfish were first observed by local fishermen in 2000, but reported established in Alabama in 2009 and, more recently, in 2012. From 2013 to 2014, surveys were conducted in NE Alabama on the Coosa River near Logan Martin Reservoir, as well as the surrounding watershed on the eastern side of the reservoir, specifically investigating for Asiatic weatherfish. Sites were surveyed using standard protocols for the surveying of wadeable streams using a backpack electrofisher and seine nets. Weatherfish were collected at 5 of 15 sites surveyed between 2013 and 2014. A total of 112 fish were collected, comprising 15% (112/738) of total catch. At 2 of the 5 sites, weatherfish occurrence was >50% of the total species observed. Weatherfish were collected in numerous habitats including lentic pools, lotic riffles, as well as in dense vegetation. Numerous size class individuals were collected (27–114mm SL) indicating populations are reproducing. Based on its occurrence in Logan Martin Reservoir and surrounding tributaries, the species appears to be expanding its range utilizing Logan Martin Reservoir as a “stepping stone” for migration. Little is known about competition between Asiatic weatherfish and native US fishes although many conservationists suggest competition is inevitable. Currently, Asiatic weatherfish co-occur in Alabama springs alongside a rare endemic fish species (coldwater dater, Etheostoma ditrema) and it is likely to encounter other sensitive species as it expands its range.

Biological invasions impact many communities and ecosystems around the world. Thus, the detection of harmful species is particularly important. In this study, the occurrence of Peacock bass Cichla kelberi in the Brazilian Pantanal was registered. The main stream of the Paraguay River, the Padre Inácio stream and their connected lakes were sampled, in the Pantanal, Upper Paraguay River basin. Six specimens were sampled including three females at beginning of maturation. The high level of turbidity of the main channel of the Paraguay River is possibly restricting the dispersal of C. kelberi to other regions of the Pantanal. But, due to the voracious piscivory of this species and the impact had in other Neotropical regions, this record highlights that the occurrence of C. kelberi can be a new threat to one of the best-conserved wetlands in the world.

The occurrence of the silver-cheeked toadfish, Lagocephalus sceleratus, is reported for the first time from Maltese waters. The specimen was caught at a depth of 15 m in a sparse sea grass Posidonia oceanica meadow. The need for a public information campaign on the danger to human health posed by the species, and to develop an early warning system of its spread, is discussed.

On January 2015 a specimen of the Red Sea spotted grouper Epinephelus geoffroyi (Klunzinger, 1870) was recorded for the first time from the Mediterranean Sea. This species apparently entered the Mediterranean via the Suez Canal (Lessepsian migrant) and is the fourth Red Sea grouper found in this region.