Mola mola is distributed from temperate to tropical oceans. The scarce reports on the occurrence of the species in the Uruguayan coast were based on incomplete morphological studies on collected specimens that could not properly discard the congeneric Mola ramsayi. This work constitutes confirmation of the occurrence of Mola mola in the coastal area of Uruguay, based on morphological characters of a specimen collected in April 2013. The fish occurred 100 m offshore in the Río de la Plata estuary (at a depth of 5 m), in an area with a water temperature between 19 and 19.5°C. Morphometric data is provided. The specimen is preserved in the Museo Nacional de Historia Natural de Montevideo (Uruguay).

The whalefish Cetomimus gillii is reported for the first time in the Tropical Eastern Pacific on the basis of a single specimen captured from off Costa Rica. This new record represents the northernmost occurrence of the species in the Eastern Pacific Ocean. A brief diagnosis and a photograph of the specimen, as well as comparative morphometric and meristic data from all species of the genus, are given.

The catfish Genidens barbus (Siluriformes: Ariidae) is an anadromous species from South America. It has been classified as vulnerable in Argentina and Uruguay due to its complex life cycle, its restricted distribution in fresh or estuarine waters and the critical levels of fishery harvesting of this species. In this work, we report the occurrence of G. barbus in three great rivers, which could represent the evidence of an extension in its migration corridor in the Paraná River Delta (Argentina).

The first record of morphologically abnormal wild fishes, Epinephelus coioides (Hamilton, 1822) and Cynoglossus cynoglossus (Hamilton, 1822), in the Parangipettai and Nallavadu landing centres along the south-east coast of India were reported. The caudal region of both of the fishes was completely deformed and fused. These abnormalities have been considered as an important indicator of environmentally induced stress to the wild fishes. Hence, the present finding highlights the need for closer monitoring of the marine environment and for the identification of the specific factor that causes these abnormalities.

Lineus mcintoshii is recorded for the first time in Indian waters. This nemertean was sighted associated with the seaweed Bryopsis plumosa on the Thiruvananthapuram coast of Kerala, India.

The northernmost record of the alien nudibranch Godiva quadricolor is reported here, about 400 km farther north than the previously published one and the farthest to be recorded from the equator. It is also the second published record of this species along the Italian coasts and the first record from the Ligurian Sea. A single specimen was reported during a scuba dive, crawling on small stones inside the Site of Community Importance ‘Fondali Noli – Bergeggi SCI’, at a depth of 3.5 m. The species, described in 1927 in South Africa, is considered to be rapidly expanding its original areal distribution thanks to maritime traffic. A review of the known actual distribution is also reported here.

A male specimen of Gasterochisma melampus of 1,310 mm fork length, was accidentally captured with a fence trap at the bay of Ilha Grande, in south-eastern Brazil (23°09′S 44°19′W) in August 2003. The specimen was captured alive and reported to be in good health at the time of capture. Posterior examination revealed that it had fed recently on cephalopods. The occurrence of cold waters from the south that reach the area of capture during the winter months may explain the presence of the species at such low latitude. The specimen represents the northernmost record of the species in the western Atlantic and the third record of G. melampus for Brazilian waters. Morphometric and meristic data are provided for the specimen, and previous records of the species in the Atlantic Ocean are discussed.

The anguillid eels found in Peninsular Malaysia were identified using a morphological analysis and that identification was further validated as Anguilla bengalensis bengalensis and Anguilla bicolor bicolor by an analysis of the eels' mitochondrial cytochrome oxidase subunit I (COI) sequences. Because of the difficulty of accurately identifying tropical eels solely on morphological analyses, previous studies had reported the occurrence of the tropical eel species Anguilla marmorata in Peninsular Malaysia. This study suggests the occurrence of Anguilla bengalensis bengalensis in Malaysian waters, confirmed by both morphological and molecular genetic analyses. Anguilla bicolor is further confirmed as the subspecies of Anguilla bicolor bicolor by molecular genetic analyses. The present study also suggests that accurate tropical eel species identification requires validation by molecular genetic analysis after a morphological observation.

Pseudoceros irretitus, Pseudoceros cruentus and Tytthosoceros lizardensis, species of the order Polycladida are reported for the first time from India. The photographs of live specimens and description are given. This study adds three more pseudocerotids to the polyclad fauna of India.

We report the first record of the scyphomedusa Rhopilema hispidum from the coast of Pakistan. The jellyfish is briefly described and the diagnostic characters are discussed. The morphological features used for the genera identification within the family Rhizostomatidae and various species of the genus Rhopilema are highlighted. We also question the previous record of Rhizostoma pulmo in Pakistan, assuming it to be a Rhopilema jellyfish and possibly the given species.

We present data on the occurrence of the invasive ctenophore Mnemiopsis leidyi in Norway after the initial observations made in 2005. Our data comes from several net sampling investigations conducted along the Norwegian coast in 2008–2014, as well as beach seine bycatch from the south coast (September–October 2005–2014). In 2008–2010, M. leidyi occurred in moderate abundances (≤0.56 lobate ind m−3) during autumn, with northernmost observations from Trondheimsfjord. Mnemiopsis leidyi was not observed in 2011–2012 and was scarce in 2013, but in 2014 it was again abundant along the south and west coasts. While temperature and salinity conditions along the Norwegian south coast and its fjords are sufficient for survival and reproduction by M. leidyi, temperature may limit egg production rates. Biological factors including food limitation as well as competition and predation by native gelatinous predators can also constrain populations. Mnemiopsis leidyi populations in Norway are likely to exhibit source–sink dynamics, with advective losses and suboptimal conditions preventing overwintering in large areas along the coast. The presence of M. leidyi in the southern North Sea, coupled with the cyclonic circulation pattern, suggests that outbreaks may nevertheless be expected in years with favourable conditions and/or significant inflow from the southern North Sea. Climate change could enhance reproduction of M. leidyi in Norway and protected inner fjords may offer a suitable habitat for establishment of local populations in the future.

Six electric rays, Narcine leoparda, were caught off the coast of Manta, Ecuador between August 2013 and January 2014. These specimens represent the first record in Ecuadorian waters and the southernmost report in the eastern Pacific for the distribution of Narcine leoparda.

Lobatolampea tetragona Horita, 2000, a member of the monotypic family Lobatolampeidae (Lobata), is reported from the Red Sea based on seven specimens collected during marine biodiversity surveys conducted in the southern and central Red Sea. The ctenophore is characterized by the following characters: paired oral lobes lacking visible auricles and bearing auricular ctenes; subpharyngeal meridional canals bearing aboral blind ends; and c-shaped gonads. Previously, the species was recorded only from Japanese waters. This finding represents the first record of L. tetragona outside of the North Pacific and represents a substantial range expansion for this species.

Specimens of Bursatella leachii Blainville, 1817 were collected from Pulicat Lake along the east coast of India at depths of up to 1 m and the maximum number of this species were recorded at a depth of 20 cm (13°33′57″N 80°10′29″E) on a sandy soil bed. A thorough literature survey on the species revealed this study to be the first report of its occurrence from this region. The present investigation describes a review on the occurrence and morphological features of this specimen.

Ten alien species were recorded in a first-time survey of the benthic biodiversity of the upper sublittoral at Sigri Bay (Lesvos Island, north-eastern Aegean Sea). The record of the mollusc Syrnola fasciata is the first in Hellenic territorial waters. The records of the brown alga Stypopodium schimperi, the bivalve Septifer cumingii, the gastropods Syrnola fasciata and Smaragdia souverbiana and the bony fish Siganus luridus constitute evidence for a further northwards extension of their geographic ranges in the Aegean Sea. The record of Cerithium scabridum is the first in Lesvos Island and partially fills the gap in the distribution of the species in the eastern Aegean Sea. We also recorded the green alga Caulerpa cylindracea, the angiosperm Halophila stipulacea and the bivalve Pinctada imbricata radiata, which are widely distributed in the eastern Mediterranean. The polychaete Marphysa adenensis, which was also found at Sigri Bay, has recently been reported for the first time from the Mediterranean as a cryptogenic species.

This paper is the first record of the blue crab, Callinectes exasperatus, in European waters and the first record for this species out of its natural distribution. Due to the similar morphology with Callinectes sapidus, a widely extended invader in the Atlantic, Mediterranean and Pacific waters, the initial determination based on morphological characters was further confirmed by DNA barcode analysis. A possible introduction vector is also discussed.

Jassa slatteryi is reported for the first time in Mar del Plata harbour, Argentina. A morphological comparison with the original description and a genetic analysis are made to corroborate the identification of specimens. The report of range expansion along the South-western Atlantic coast is discussed.

We report for the first time the association of some caridean shrimps with the octocoral Carijoa riisei (Cnidaria: Clavulariidae) and the sponge Dragmacidon reticulatum (Porifera: Axinellidae), in estuaries from north-eastern Brazil. The alpheid shrimp Synalpheus apioceros, Synalpheus fritzmuelleri, Alpheus formosus, Alpheus carlae and the palaemonid Cuapetes americanus are reported in association with Carijoa riisei. The latter two species, plus the alpheid Alpheus buckupi, are recorded in association with D. reticulatum.

Two mariculture escapee specimens, the West Atlantic Southern Flounder Paralichthys lethostigma and the Red Drum Sciaenops ocellatus, were collected from the Mediterranean coast of Israel. The former was reported for the first time from the Mediterranean, while the latter for the second time. A single aquarium escapee or released specimen of the Giant Snakehead Channa micropeltes was collected for the first time from Lake Kinneret (Sea of Galilee).

New records of the hyperiid amphipod Hyperia curticephala M. Vinogradov & Semenova, 1985 are presented based on the record of 43 specimens collected from several specimens of the pelagiid jellyfish Chrysaora plocamia (Lesson, 1830) (Cnidaria: Scyphozoa), washed ashore during January 2015 in the port of Caldera (27°S), Atacama Region, northern Chile. This is the second record of H. curticephala after its description, extending the previously known southern distribution record of this species by about 443 km and confirming its association with C. plocamia.