The Japanese shore crab Hemigrapsus sanguineus is recorded for the first time from a Black Sea locality: Tomis Marina in Constanţa, Romania. The suggested vector of introduction is as adults in the hull fouling of yachts. The species has not established and salinity requirements for larval development make it unlikely that it will ever establish in the Black Sea.

The paper presents the first record of the Ponto-Caspian amphipod crustacean Pontogammarus robustoides G.O. Sars, 1894, in the Gulf of Riga, Baltic Sea. Eight individuals of this invasive amphipod were found in June 2009, in shallow waters of the gulf near Yurmala city. Most likely this species entered the Gulf of Riga from Latvian rivers emptying into the Baltic Sea, where it was previously found. However, introduction via ships coming from either southern or north-eastern parts of the Baltic Sea is also a possibility.

We recorded the first sighting and collection of the non-native, invasive red lionfish (Pterois volitans [Linnaeus, 1758]: Scorpaenidae) in the southern Gulf of Mexico, off the northern Yucatan Peninsula. In December 2009, two individuals were sighted (one of them speared) at 38 m depth over a reef formation, about 58 km northwest of the Alacranes Reef National Park, which is located 130 km off the northern coast of the Yucatan Peninsula, Mexico. More than 20 years after the introduction of P. volitans into the western Atlantic, specifically off the Florida and North Carolina coasts, the invasion circuit now appears to be closing in, since this new record was made about 800 km from the Dry Tortugas and Marquesas, Florida. This recording appears to be the first introgression of the P. volitans population into the Gulf of Mexico via larval transport.

Five specimens of the non-native three spot gourami (Osphronemidae: Trichogaster trichopterus) were collected from a small pond near the northern coast of Jamaica in June 2009. The collection represents the first documentation of this species in Jamaica. Origin of the introduction is not known. Herein, we discuss the occurrence of this species in Jamaica and possible threats posed to the island’s native fish fauna.

This paper presents new records of Asian clam Corbicula fluminea in the rivers Mero, Sil and Deva. Records from the Rivers Sil and Deva showed the increase of its spread in the Miño river basin. Findings in the Mero basin represented the first Iberian record of this species outside the Miño basin. Furthermore, it was the most north-western record in the Iberian Peninsula.

Chains and solitary individuals of the slipper limpet Crepidula fornicata were found, some with egg capsules, at several localities within Belfast Lough on the north-east coast of Ireland during 2009. The species is widely dispersed, being found on the lower shore to depths of 7 m attached to scallops, mussels and stones and so is considered to be established. Shell winter growth checks indicated a possible arrival in or before 2004. While there have been previous records of this invasive species in Ireland, this is the only known established population.

So far the angular crab Goneplax rhomboides (Linnaeus, 1758) was mostly a northeastern Atlantic and Mediterranean species and was quite rare in the North Sea where no evidence for sustainable populations existed. In 2008 and 2009 a total of 82 individuals of Goneplax rhomboides (Linnaeus, 1758) were found at 22 widespread locations in the southern North Sea indicating that this species is now well established in the area.

The mysid Katamysis warpachowskyi Sars, 1877 originated in the Ponto-Caspian region and the associated river systems. The first evidence of its transgression of the limits of the watersheds of its natural Ponto-Caspian origin was found when three individuals were recorded in October 2009 in eastern Lake Constance (Austria). In March 2010, K. warpachowskyi comprised 10% of the mysid assemblage and was mainly found in rocky habitats. On both sampling dates, breeding females were present. Before this invasion, Limnomysis benedeni Czerniavsky, 1882, was the only mysid in Lake Constance and is also distributed in the Rhine river system. Since the two mysids coexist in Lake Constance, K. warpachowskyi will likely become established in the lake and further expand into the main part of the Rhine. K. warpachowskyi is known as a benthic organism and feeds on detritus and small algae; therefore, the impact on the lake ecosystem should be weaker than that of pelagic mysids.

The aim of this paper is to present new data and review the current distribution of Corbicula spp. in France. Three morphotypes were recorded during the study - “round form”, “light R form” and “saddle form”. During April 2009, Corbicula spp. were found in several watercourses in France, including three rivers (Canal de la Somme, Oise and Vilaine) where the taxa were not previously reported. In addition, this is the first report of form S in the River Seine and, the first record of the “light R form” in the River Gard. Molluscs of the genus Corbicula are considered to be a well established alien species in large rivers.

The Emperor angelfish Pomacanthus imperator (Bloch, 1787) was recorded for the first time from the Mediterranean. Its occurrence there is due to either migration from the Red Sea (Lessepsian migration) or as an escapee from the aquarium trade. The spotbase burrfish Cyclichthys spilostylus (Leis and Randall, 1982) was recorded for the second time in the Mediterranean, almost two decades after the first record.

A single specimen of Priacanthus sagittarius was captured by a commercial trawler off the Mediterranean coast of Israel on 28th November 2009. This is the first record of the species, and possibly the first alien member of the Priacanthidae from the Mediterranean Sea.

Four alien species of Red Sea Cardinal fishes have been reported to date from the eastern Mediterranean, three of them discovered during the last five years. Here we report the finding of a fifth alien cardinal fish Cheilodipterus novemstriatus (Rüppell, 1838) in the eastern Mediterranean Sea. The fish was collected from the wreck of an old sunken ship off the Tel Aviv coast.

We report the presence of the invasive Indo-Pacific red lionfish (Pterois volitans) in 23 localities of the Venezuelan coast, southeastern Caribbean Sea. This finding is based on ten specimens collected at Parque Nacional Archipiélago de Los Roques (PNAR, Dependencias Federales), Playa Cal, Caraballeda and Puerto Carayaca (Estado Vargas) and 30 specimens observed in 18 localities of PNAR, Parque Nacional Morrocoy (Estado Falcón), Bahía de Cata, Ensenada de Cepe (Estado Aragua), Puerto Cruz, Chichiriviche de La Costa, Mamo, Catia La Mar, La Guaira, Macuto, Caraballeda (Estado Vargas) and Farallón Centinela (Dependencias Federales). The specimens were collected and observed from November 2009 to June 2010. This is the first published report documenting their occurrence in Venezuela.

The round goby (Neogobius melanostomus Pallas, 1811) has been present, since the 1990s, in the Gulf of Gdańsk where it forms a strong population and where the species is locally the most important fish in shallow inshore areas. No similarly large, independent round goby population in the Baltic Sea area has been found beyond the Gulf of Gdańsk and the adjacent Vistula Lagoon. As shown by the research carried out in 2009, the round goby is abundant also in the River Odra estuary, which may provide evidence of the presence of a local, reproducing population.

Living individuals of Asian clam Corbicula fluminea (Müller, 1774) (Bivalvia: Veneroida: Sphaeriacea: Corbiculidae) have been recorded for the first time in the Republic of Moldova (Prut River basin, November 2009). Perhaps, this invasive species entered the Prut River basin from the Romanian or Ukrainian territories, where this species was previously recorded. This invasive species may negatively influence the native bivalves as they are in competition for both nutrient resources and substrate.

The Ponto-Caspian mysid shrimp Hemimysis anomala was found in Ireland for the first time in April 2008. During 2009 it was found throughout most of the Shannon River Navigation (~250km) occurring in swarms at estimated densities of ~6 per litre in shallows and in lower densities at depths of ~20m where its distribution overlaps with the native Mysis salemaai. Broods were found from March to September. It occurs mainly in lakes but small numbers were found at one river site. In summer, shallow-water specimens were found only during the night but in winter could be captured in daytime. It is not known by what means the species arrived in Ireland, or when.

The Australian spot jellyfish Phyllorhiza punctata has not been recorded previously for any coast of Mexico. A giant jellyfish was recorded for the first time in June 2006 in Laguna de Mandinga, southwestern Gulf of Mexico. Between 2007 and 2008, another three adult specimens were collected and later in May 2009 and April-June 2010 a great number of juveniles and adults were observed, of which 142 were collected. The presence of juveniles and adults throughout five consecutive years indicates that the species has a seasonal pattern. It migrates from the Sistema Arrecifal Veracruzano (SAV) into Laguna de Mandinga during the spring, aided by the tide that flows along the estuary of the Jamapa River. The population then decreases at the end of the summer, during the rainy season, when salinity decreases (10 psu). The recruitment area of the polyps is probably associated with the coral reefs in the SAV.

The caprellid amphipod Caprella mutica became rapidly established in the North Sea, on the west coasts of Scotland and Ireland, the Irish Sea and English Channel. The first record for C. mutica from Jade Bay, in the southern North Sea, is reported here. High densities exceeding three-hundred individuals per wood panel (approximately 7000 ind./m^-2) were found on wooden settlement panels in August/September 2009 associated with the tube-building amphipod species Jassa marmorata and Corophium acherusicum. The extensive mud-tube colonies of J. marmorata and C. acherusicum on the panels provide a suitable habitat for C. mutica attachment.

In September 2009 a non-native shrimp species was found at two sampling sites in Varna Lake, a brackish coastal water body connected to the Bulgarian Black Sea. Diagnosis based on morphological features confirmed that the examined individuals belonged to the species Palaemon macrodactylus Rathbun, 1902. All specimens found were ovigerous, 2+ year females suggesting the presence of a viable population in the system. Possible ways of introduction and community effects for Varna Lake are discussed.

The first invasive record of the green alga Caulerpa racemosa (Forsskål) J. Agardh in the Mediterranean Sea was in 1990 in Tripoli (Libya) (J. Agardh) and since that period, this Chlorophyta has been rapidly spreading to all Mediterranean countries. However, very few assessment studies have been carried out along the Algerian coast. In this paper, we present, for the first time new observation data concerning an indicated proliferation of this invasive species in Salamandre and Stidia (Gulf of Arzew, western Algeria); both these sites are very important for sea fishing activities and traffic.