The age and growth of the snowy grouper, Epinephelus niveatus, from central and south-eastern Brazil were studied by otolith analysis from a sample of 341 specimens, ranging from 325 to 1216 mm in total length (TL) caught with bottom longlines between 1996 and 1998. Otolith length grew proportionally with the increasing TL of the fish. Marginal increment analysis indicated that a single opaque band forms each year during autumn–winter. The maximum estimated age was 54 years, which significantly extends the previously estimated life-span of 21–29 years for this species. The von Bertalanffy growth parameters for both sexes were estimated as L∞ = 1098.4 mm TL, K = 0.062 year −1 and t0 = –2.68. The study revealed differences in mean length-at-age and size at recruitment, as well as in growth parameters between the central and the south-eastern Brazilian coast, which can be attributed mainly to different fishing pressures. The snowy grouper was found at depths of 82–492 m, and showed a positive relationship between age and depth, suggesting differential movements of older fish to deeper waters.

Records of beaked whales stranded in the Falkland Islands and at South Georgia were collated for the period 1866 to 2008. Thirty-eight records, involving at least seven species in four genera, were documented. Strap-toothed whales (Mesoplodon layardii Gray, 1865) were the most common species with 11 records, including two neonates. Andrews' beaked whales (M. bowdoini Andrews, 1908), Arnoux's beaked whales (Berardius arnuxii Duvernoy, 1851), Cuvier's beaked whales (Ziphius cavirostris Gray, 1823), Gray's beaked whale (M. grayi van Haast, 1876), Hector's beaked whales (M. hectori Gray, 1871) and southern bottlenose whales (Hyperoodon planifrons Flower, 1882) were recorded on three to five occasions. In several cases, records suggested potential temporal changes in range. For example, Arnoux's beaked whale has not been recorded in the Falkland Islands since 1965, whilst Gray's beaked whale was not recorded prior to 1981, and Andrews' beaked whale was not recorded before 1987. Although the number of records for each species is low, this could reflect changes in water temperatures and/or prey availability. Overall, this study confirms that the Falkland Islands–Tierra del Fuego region is one of the world's key areas for beaked whales.

‘Pliocardia' krylovata, sp. nov. (Bivalvia: Vesicomyidae: Pliocardiinae) is described from cold seeps off the coast of the Nicoya Peninsula, Costa Rica (700–1000 m depth). The phylogenetic position of ‘P.' krylovata was assessed by both morphological comparisons as well as nucleotide data from the cytochrome c oxidase I gene. Within the vesicomyids, ‘P.' krylovata belongs to the Pliocardiinae and its closest relative is ‘Calyptogena' ponderosa, which also bears some morphological resemblance to the genus Pliocardia, perhaps suggesting a need for reanalysis of not only its generic designation, but also the entire Pliocardiinae subfamily. ‘P.' krylovata has morphological similarities to ‘Pliocardia' bowdeniana and ‘Vesicomya' crenulomarginata, recently reassigned to the genus Pliocardia, including a thick shell, obvious rostrum, pointed posterior end, and a sculptured shell with concentric ribs on the outer surface, to name a few. It is morphologically distinguished, however, by having a complex pallial sinus and remarkably deep escutcheon.

The mortality of the bottlenose dolphin, Tursiops truncatus, on the southern portion of Rio Grande do Sul State coast was investigated based on 914 beach surveys conducted between 1969 and 2006. A total of 188 stranded bottlenose dolphins were recorded during this period, indicating a 1.8M:1F sex-ratio of those animals sexed (N = 79). Mortality was low in calves, high in juveniles and sub-adults and slightly lower than in adults. The overall mortality was clearly seasonal overlapping with higher fishing efforts in the Patos Lagoon Estuary and adjacent coastal areas, where most individuals washed ashore. Analysis of a continuous 14-year long subset (1993–2006) of the data indicated relatively low levels of mortality between 1995 and 2000 and a marked increase between 2002 and 2005 followed by an apparent drop in 2006. By-catch was responsible for at least 43% of the recorded mortality between 2002 and 2006. Juvenile males were more susceptible to incidental catches. Among females, by-catch of adults represented 75%. Results of a potential biological removal analysis suggest that current levels of fishing-related mortality are unsustainable for the small resident population of bottlenose dolphins that inhabits the Patos Lagoon Estuary, and that this population may be declining.

New arcid species belonging to the genera Paranadara gen. nov., Acar and Asperarca (new record) are described for the western Atlantic Ocean based on shell morphology. Paranadara taludae sp. nov., Acar naturezae sp nov., Acar oliveirae sp. nov. and Asperarca tarcylae sp. nov. were collected off north-eastern Brazil between depths of 70 and 690 m, whereas Acar lepidoformis sp. nov. was dredged off the State of Rio Grande do Sul (southern Brazil) at a depth of 141 m. There are no species along the Brazilian coast that are morphologically similar to Paranadara taludae sp. nov. Acar naturezae sp. nov., Acar lepidoformis and Acar Acar oliveirae sp. nov. are similar to this genus due to shape, ligament, presence of concentric lamellae cut by radial threads, a broad dorsal area and a markedly narrowed anterior region in comparison to the posterior region, which is strongly expanded. Asperarca tarcylae sp. nov. is similar to this genus due to the presence of a small edentulous region below the umbo and smooth inner margin.

The original description of Tegula ignota was based on three shells found on the coast of Totoralillo Sur, northern Chile. Until now, there are no reports of living specimens of the species. The present study redescribes this snail based on shell, radula, epipodium and mantle characteristics observed in living specimens collected from the subtidal zone of La Boca, central Chile. Additionally, we extend the distribution of T. ignota more than 700 km to the south-eastern Pacific with additional material. Molecular analyses based on the 16S ribosomal DNA mitochondrial gene show that T. ignota is most closely related to Tegula atra than other Chilean species of Tegula. Voucher specimens of T. ignota were deposited in the Museo Nacional de Historia Natural de Chile.

Since 2003, as part of the LIFE project ‘Del.Ta.’ (NAT/IT/000163) a bottlenose dolphin community has been studied in order to assess the impact of increasing boat traffic in the Pelagie Archipelago (Sicily, Italy). During the summer of 2006 and 2008, land-based surveys were carried out at Lampedusa, one of the Archipelago's Islands, at set hours from 6 locations (7 in 2008) in standard weather conditions. Continuous horizon scanning and focal group sampling methods were used to study dolphin presence and behaviour. Dolphin–boat interactions were recorded for each sighting. A total of approximately 559 hours were spent monitoring and 83 sightings were recorded. With regard to the different types of vessels, interaction with sailing boats was always neutral, whereas fast boats caused the interruption of all activities and avoidance behaviour. Positive interaction occasionally occurred with bottom trawling fishing boats. Interactions recorded when fishing and powered engine boats approached within 200 m predominantly resulted in a negative reaction from the dolphins (approximately 70%) and dolphin behaviour was affected in terms of occurrence and patterns. Behavioural analysis showed that the animals reduced the frequency of behaviours related to feeding, social and relaxing activities. The dolphins also increased information-gathering behaviour such as spyhopping. The use of Markovian chain models revealed evidence of disruptions in sub-sequences made up of behaviours often associated with feeding. After boat departures, the animals rarely restarted their previous activity and persistence of this effect could have long-term consequences as a result of non-habituation. Sighting duration also decreased in the presence of vessels. The possible negative long-term effect of the presence of boats may be indicated by the lower mean sighting duration in 2008, when the highest presence of powered engine boats was recorded. In view of the scenario outlined above, local authorities need to enforce the requirement of maintaining a distance of over 200 m away from the animals for all types of boat and also promote regular land-based surveys of vessel impacts for tourist boats and dolphin watching cruises.

Coastal waters are being subjected to underwater noise generated by increasing numbers of leisure and tour boats. Such noise has the potential to impair the hearing of neighbouring bottlenose dolphins, particularly as the noise from several distributed boats could summate at the point of reception. This potential has been assessed by comparing small boat noise, recorded over a range of 8–532 m, with noise that is known to induce hearing impairment in the form of a temporary threshold shift (TTS) or permanent threshold shift (PTS). Extrapolation of broadband boat noise levels yielded a minimum source sound pressure level of 156 dB re 1μPa at 1 m. An equal-energy model for TTS-onset predicted that boat noise could induce a TTS after 1 hour's exposure at 1.3 m and after 8 hours' exposure at 2.3 m. These distances increased with additional adjacent boats. Leisure boats are unlikely to induce a PTS, even at close range.

Morphological examination of several specimens of aeolid nudibranchs collected from the Ross Sea, Antarctica, revealed an unexpectedly high number of species. Based on the collected material the following species are re-described and for the first time their colour, reproductive anatomy and radula are illustrated together: Eubranchus glacialis, Cuthona modesta, Cuthona crinita, Cuthona elioti and Guyvalvoria paradoxa. Additionally, a new species of Cuthona is described from this area. The new species differs from other Antarctic and sub-Antarctic species of Cuthona in its external appearance, radular morphology and reproductive anatomy. Information on the egg mass and embryonic development of several species is provided.

Studying interactions between cetaceans and humans is fundamental to assess their ecological significance and the impact of human activities on marine wildlife. Delphinids have historically been associated with human maritime activities, and while evidence suggests that such interactions are becoming more frequent worldwide, these remain poorly studied. Areas of potential interaction and differences in dolphin affinity to interact with humans were used to test hypotheses about the spatial distribution and temporal variation in dolphin–fisheries interactions off the highly productive Alvarado lagoon, in the western Gulf of Mexico. Line-transect surveys yielded 928 dolphin, 980 vessel, and 320 fishing gear target records, the latter involving mostly the shrimp fishery. No temporal differences were found in daily relative abundance of dolphins ( = 8.1 h−1, SD = 9.7), vessels ( = 7.8 h−1, SD = 5.9) or fishing gear ( = 2.4 h−1, SD = 2.6) between two consecutive years. Non-random spatial distributions indicated higher target concentrations at the lagoon entrance; however, dolphins and fishers were found to evade each other, possibly to prevent competition; dolphins only interacted with gillnets (28.6% of vessels and 22.6% of fishing gear). We observed small areas of potentially intentional and random encounters outside the entrance of the lagoon and low or null potential for interactions elsewhere. Only 18.9% of dolphin schools (44.8% of the 172 photo-identified animals) interacted with fisheries mostly by chance. Resident individuals (N = 23) tended to avoid humans, likely in response to negative reinforcement caused by aggressions from fishers. Hence, the potential intentionality of a few individuals to interact with fisheries, show they bare higher risks while attempting to benefit from gillnetted prey. This research unveils the chronic and acute exposure of the dolphin community to artisanal fisheries within the area, having important reciprocal consequences on their distributions and activities.

Nassarius nitidus is a marine snail species with a widespread distribution along European shorelines from the North Sea to the Mediterranean and Black Seas. Despite its widespread distribution, N. nitidus has been largely neglected due to taxonomic confusion with the congeneric Nassarius reticulatus. Discrimination between these two Nassarius is particularly challenging in areas where their ranges overlap: the European Atlantic and western Mediterranean. Here, we propose the use of the mtDNA gene cytochrome c oxidase subunit I (COI) to discriminate between these two morphologically similar congeneric species. A numerically comprehensive sampling of the areas of overlap reveals strong population-level differentiation in N. nitidus, particularly between the Mediterranean and the Atlantic. Despite this strong population structure, we found a wide (9.6 ± 1.6% mean K2P corrected sequence distance) barcoding gap with N. reticulatus that guarantees that COI barcodes may serve as a reliable diagnostic tool. A protocol using species-specific restriction patterns was developed to allow a quick and accurate discrimination between these two cryptic species.

The genus Kolga has been revised. Kolga nana (Théel, 1879) is re-established and a new species, Kolga kamchatica sp. nov., is described. The new species was found in the Kurile–Kamchatka Trench at 6225–6236 m water depth. The three species of Kolga, K. hyalina, K. nana and K. kamchatica, differ mainly in morphology of tube feet ossicles. For the first time, swimming activity is reported in K. nana.

Autonomous acoustic data loggers can provide useful data on habitat use and activity patterns of vocalizing cetaceans. One type, the T-POD, uses filters that can be set to match the click characteristics of the target species. We used wideband acoustic recordings to document typical click spectra of bottlenose dolphins in Doubtful Sound, New Zealand, in order to develop T-POD settings optimal for that population. T-PODs at these settings made between 8 and 33 times as many detections as accompanying T-PODs set as in other studies of this species, confirming the value of optimizing settings for a particular dolphin population. Maximum detection range was 1313 m, and mean range of first detection was 593 m. Of 45 groups observed within 500 m of the T-POD, 47% were detected acoustically. Effective detection radius was estimated at 266 m (95% CI 222–317 m).