One of the most problematic fishing methods in terms of by-catch and discarding is prawn-trawling. This paper analyses the incidental catch of an artisanal trawl fleet during two discrete Artemesia longinaris fishery seasons (2002 and 2004). The fishery season of A. longinaris operates monthly and it takes place in the surrounding area of the Barra do Rio Grande. Sampling was carried out during the fishing season (April–December) always on the same artisanal trawl boat. An observer was included on-board to avoid loss of information due to discards made by the fishermen at sea. Fifty species were caught: 38 fish and 12 crustaceans. Discrete fauna abundance and composition were recorded in analysed years, with higher by-catch ratios associated with elevated rainfall and low salinity. The overall discard ratio was 1:5.6, with values ranging from 1:11.3 in 2002 to 1:2.5 in 2004. The most striking differences between both years analysed were observed during autumn (1:75 in 2002 and 1:11.30 in 2004) and winter (1:16 in 2002 and 1:0.97 in 2004), while spring presented similar values (1:8 in 2002 and 1:4 in 2004). The discard ratio estimated in terms of number showed a different pattern, presenting overall values of 1:2.24 in 2002 and 1:0.5 in 2004. Higher estuarine runoff may have increased biomass production in the surrounding area of Patos Lagoon during 2002, sustaining higher abundance of estuarine-related and marine species in the area, as well as higher mean trophic level and abundance of top-predators. Conversely, A. longinaris production was consistently lower, since this marine species does not tolerate marked reductions in salinity. In 2004, salinity was higher, associated with low rainfall and favouring A. longinaris abundance in the area. During this dry year, the target-species was dominant in samples resulting in very low by-catch ratios, especially in winter (1:0.97). The catch was mainly composed of juvenile fish, since fishery is performed in nursery grounds.

We describe the phytoplankton community and biomass during a summer coccolithophorid bloom sampled over the Patagonian shelf (48.5°S–50.5°S). Those phytoplankton species can contribute to the flux of calcium carbonate out of surface waters. Results from both microscope and high-performance liquid chromatography (HPLC) analysis are shown to complement information on the phytoplankton community. From CHEMTAX analysis of HPLC data, the most important organisms and groups identified were the coccolithophorid Emiliania huxleyi, the haptophyte Phaeocystis antarctica, dinoflagellates, diatoms, cryptophytes, prasinophytes and cyanobacteria. Phytoplankton microscope counts were converted into phytoplankton group-specific biovolume estimates. Although some microscope-identified taxa could not be determined by CHEMTAX, e.g. the autotrophic ciliate Myrionecta rubra, cluster analyses from both techniques showed similar results for the main groups. Both Emiliania huxleyi cell concentration and biomass, and the pigment 19′-hexanoyloxyfucoxanthin were the most important biological features during the sampling period. At surface, nitrate was moderately high (0.2–4.2 µM) in coccolithophorid-dominated samples, whereas phosphate (<0.33 µM) and silicate (<1.35 µM) concentrations were low. Among the environmental factors low Si:N ratios were mainly associated with the dominance of E. huxleyi. Competition and probably differential grazing could also promote a coccolithophorid outgrowth over other photoautotrophs during the summer season in the Patagonian shelf.

Here we report the second and third known specimens of Cephalopholis fulva with partial melanic coloration, photographed at Fernando de Noronha Archipelago and Camamu Bay, south-western Atlantic. While the species exhibits a wide range of colorations, the melanic pattern is an aberration only recently reported. Since C. fulva is common within its area of distribution and is of importance to fisheries, increasing records of melanism can either result from higher frequency than previously thought or, alternatively, that this condition is becoming more common.

The surroundings of the rocky island of Helgoland (German Bight, south-western North Sea) are one of the best-studied sites in European seas with species occurrence data available for nearly 150 years. As the area is strongly affected by global change (e.g. increase in mean sea surface temperature at Helgoland by 1.67°C since 1962), ecosystem structure and function are expected to change more than those of average marine systems. The paper presents a supplement to the local amphipod species inventory (5 nautical miles around the island). At least seven species of this ecologically important taxon seem to have newly established themselves at Helgoland since the late 1980s: Ampelisca typica, Amphilochus brunneus, Caprella mutica, Cheirocratus assimilis, Monocorophium acherusicum, Orchestia mediterranea and Orchomenella crenata. Most of them are not only new for the Helgoland area, but also for the German Bight; and two species (Amphilochus brunneus and Orchomenella crenata) are even new to the North Sea as a whole. Out of the seven new species, one (Caprella mutica) is a neozoon from the north-western Pacific. The other six species show clear warm water affinities (oceanic–Lusitanian species) which suggest a recent range expansion in the context of climate warming. The establishment of an increasing number of species formerly probably absent from the area does not seem to be compensated by losses of species, so that local species diversity is expected to increase.

Four specimens of the clingfish Tomicodon zebra were caught on the intertidal zone El Pital, El Salvador, Central America. This record extends its known range two latitudinal degrees southward in the Tropical Eastern Pacific.

Specimens of the clam Panopea globosa were collected in the Gulf of California, Mexico in 2009. Tiny crabs were found living inside the clam, being Pinnaxodes gigas. Since both the description and the scarce subsequent reports of P. gigas were performed only from single free-living specimens, this is the first record of P. gigas associated as a symbiont of any host. This is also the first record of any geoduck clams as host of commensal crustaceans, and the second record of a pea crab of the genus Pinnaxodes encountered infesting bivalves in the Pacific.

The ringed basket star Astrodictyum panamense is an ophiuroid resident of coral and rocky reefs from the central and southern Gulf of California and oceanic islands from the eastern Pacific. This paper presents new records of this species obtained from fieldwork and internet sources, and includes its northernmost and westernmost occurrence in the eastern Pacific (Adair Bay, Gulf of California, and Tortugas Bay, on the Pacific side of Baja California, respectively), as well as Roca Partida Island, in the Revillagigedo Archipelago.

In the past half century, a number of studies have described the general composition of the mesozooplankton of Southampton Water, but little attention has been paid to the occurrence of parasitic and commensal species. In order to fill this gap, the occurrence and distribution of parasitic/commensal species was investigated in three fixed stations along the estuary in 2001/2002. A total of 16 parasitic taxa were identified, including 11 new records for the zooplankton of Southampton Water. The most frequent and abundant parasitic taxa observed in the estuary were Peltogaster paguri, Sacculina carcini, Siphonostomatoida copepodites and cryptonistic forms of isopods. This study is the first report on ‘free-forms’ of parasitic/commensal species within the mesozooplankton of Southampton Water being also a reasonable indicator of the presence of the infected/associate host in the estuary or surrounding areas.

The mysid Hemimysis lamornae mediterranea Bacescu, 1936 is described from specimens sampled in the Ebro Delta, Spain, north-western Mediterranean. To date, this subspecies was only known from the Gulf of Naples and Marseille; this is the first record of the H. lamornae mediterranea on the Iberian Peninsula coast. Hemimysis lamornae mediterranea is distinguishable from its closest congeners, H. lamornae typica (Couch, 1856) and H. lamornae pontica (Czerniavsky, 1882) by the number of setae, the shape of the maxilla, and the relatively smaller number of spines on the uropod endopod and on the lateral margin of the telson.

The population structure and biological aspects of the shallow water mysid Mesopodopsis orientalis were studied in the Versova mangrove, Mumbai, India. The monthly collections ranged from 0–2104 ind.m−3with an average of 78.6 ind.m−3. The sampled population was found in a wide range of temperature (25.5°C to 34°C) and salinities (20.3 to 37.1). Carapace length significantly correlated with total body length (P < 0.01). Mesopodopsis orientalis breed throughout the year but there is a seasonal variation in the intensity of breeding. The size of mature males and females was at maximum during the post-monsoon period. The species produced more than one generation per year and the number of embryos carried by a single female ranged from 6–18, and was correlated with female body length (R2 = 0.69). Egg size varied between 0.32 and 0.45 mm, with no correlation with length of females.

The species diversity of pontoniine shrimps (Decapoda: Palaemonidae: Pontoniinae) previously recorded in the vicinity of Lizard Island, Great Barrier Reef (GBR), Australia, were compared with new records obtained during a recent three-week expedition as part of the CReefs Project, a field project of the Census of Marine Life. Few previous investigations at this location had discovered 18 species of pontoniine shrimps distributed among 12 genera. In contrast, relatively little effort, approximately 35 hours sampling (40 dives), was required to increase this list more than twice adding 20 new species records from 15 pontoniine genera for the locality including 6 species and 1 genus reported from Australian waters for the first time and 1 genus and 4 species new to science. This large increase in species was enumerated with little additional effort and the relatively low total species diversity of these shrimps known from this location compared to species known from the southern GBR (e.g. Heron Island), where overall diversity is expected to be less, strongly indicates that the enumeration of these shrimps from the northern GBR is far from complete.

Length–weight relationships of four pipefish and two seahorse species from Tunisian waters are presented in this paper: the straight-nosed pipefish Nerophis ophidion, the black-striped piperfish Syngnathus abaster, the greater pipefish S. acus, the deep-snouted piperfish S. typhle, the short snouted seahorse Hippocampus hippocampus and the long-snouted seahorse Hippocampus. ramulosus. Overall, 2424 specimens of these six syngnathid species were weighed and measured. The sample size ranged from 14 for N. ophidion to 1773 for H. ramulosus. The values of the slope b in the length–weight relationships (W = aLb) varied between 1.836 (S. typhle) and 5.476 (N. ophidion). Linear regressions of length–weight relationships were significant for all species. We have calculated a positive allometry in weight versus length for N. ophidion, an isometry for H. hippocampus and H. ramulosus and a negative allometry for S. abaster, S. acus and S. typhle.

The occurrence of the merluccid Macruronus novaezelandiae from tropical waters off Bahia, eastern Brazil, is reported for the first time due to the capture of an adult of 712.3 mm standard length in May 2008, from a depth of 400 m. Until then no specimen had been reported north of 32°29′S on the South American Atlantic coast. This new record extends the species' range to about 2500 km northwards along the Brazilian coastline and is the first ever from tropical waters in the world. A comparison of the morphometric characters is provided.

The present study reports new records of the invasive pygmy mussel Xenostrobus securis in six brackish-water localities in the western Mediterranean. Until now X. securis, whose native range includes southern Australia and New Zealand, was also known from the northern Adriatic Sea and southern France. Along the coast of northern Tuscany (Italy) X. securis invaded brackish-water canals in the area between the port of Leghorn and the mouth of the Arno River. Moreover, this mussel has been found in one inner site of the Gulf of Olbia (north-eastern Sardinia, Italy) and at the mouth of the Fluvià River (northern Catalonia, Spain). As an ecosystem engineer, X. securis is an ecologically important species, heavily altering pre-existing benthic communities. Given that its presence in other western Mediterranean sites is highly possible, we recommend a closer monitoring of brackish-water biotopes.

A total of 168.4 hours of visual cetacean survey work was carried out in association with two geophysical surveys in Montserrat waters (eastern Caribbean) during December 2007 and May 2010, using a seismic vessel as a platform of opportunity. Nine cetacean sightings were recorded: pantropical spotted dolphin Stenella attenuata (N = 2), Fraser's dolphin Lagenodelphis hosei (N = 1), sperm whale Physeter macrocephalus (N = 1), humpback whale Megaptera novaeangliae (N = 1), and sightings of unidentified dolphins (N = 1) and large whales (N = 3). A total of 73.3 hours of acoustic monitoring effort was carried out during December 2007, resulting in 19 cetacean detections. Sperm whale (N = 10) and unidentified dolphin (N = 7) detections predominated. Two acoustic detections were of pantropical spotted dolphins, corresponding with visual sightings. An opportunistic sighting of 14 pygmy killer whales Feresa attenuata during October 2008 was reported. Although the humpback whale was known previously for Montserrat waters, the sightings of other species represent the first verified records for the state.

The capture of the species Bythocaris cosmetops in the Alboran Sea (southern Spain, western Mediterranean Sea), previously known from only two specimens from the Atlantic, Sierra Leone (south-west Africa) and the northern Bay of Biscay (north-west Europe), represents the first record of the genus and species in the Mediterranean Sea and Iberian Peninsula (south-west Europe). New data on morphology, biology and habitat are provided and discussed.