The study of the feeding habits of elasmobranch populations should help to elucidate the ecological role of these fishes in the marine ecosystem. Feeding habits of the apron ray, Discopyge tschudii from San Jorge Gulf were investigated. An evaluation of whether the diet of D. tschudii changes with body size, seasons, maturity stage and sex was performed using a multiple-hypothesis modelling approach. Discopyge tschudii preyed mainly on polychaetes. The consumption of polychaetes was higher in males. Also, amphipods and siphons of clams were preyed more heavily in the cold season and Munida gregaria in the warm season. Stomatopods were consumed more with increasing body size. All prey categories were independent of maturity stage. We concluded that D. tschudii is a benthic feeder.

Niche differentiation is the process by which species evolve different forms of resource use, and is used to explain the co-occurrence in a variety of habitats. The Bayesian framework of isotopic niche through quantitative niche metrics was applied to estimate and compare the niche breadth of two sympatric coastal dolphins Pontoporia blainvillei and Sotalia guianensis in a tropical marine area. The standard ellipse areas (SEAs) based on species were quite similar, but the SEAs based on age class showed that the matures’ niche space is larger than the immatures’ for both dolphins. A probabilistic comparison of SEAs indicated that specific differences are negligible compared with age class differences. Trophic level measures (δ15N range) indicated that the dolphins are comparable as top predators, and that immature specimens have a lower range of trophic levels than mature ones. In terms of variability of food sources (δ13C range), S. guianensis showed a larger value than P. blainvillei and mature specimens had larger δ13C range than immatures for both species. In general, P. blainvillei and S. guianensis were similar in the niche metrics, with SEAs overlap of 52.1 and 39.7%. The immature specimens showed reduced isotopic niche overlap between species (<3%). In conclusion, Pontoporia blainvillei and S. guianensis specimens have similar isotopic niches, but pronounced differences between immature and mature specimens, both intraspecific and interspecific. Isotopic niche and quantitative metrics along with previous data on stomach contents provide a strong representation of species niche and their relationships.

Sampling of the demersal ichthyofauna of Guanabara Bay was conducted bimonthly for 2 years at 10 stations distributed along a hydrobiological gradient. A total of 16,081 Tetraodontiformes specimens were collected, representing 10 species distributed among Ostraciidae, Monacanthidae, Tetraodontidae and Diodontidae. Tetraodontiformes appear to be well adapted to hydrological variations and inhospitable conditions prompted by intense eutrophication. However, abiotic factors traditionally considered important in estuarine community structure play a secondary role in the distribution of Tetraodontiformes. The type of sediment appears to be the most important physical factor but acts only as an indicator of ecological domain. The low explanatory power of physicochemical variables, in addition to the relative stability of the bay's ichthyofauna, suggests an influence of biological parameters. The species exhibited wide variation in their use of Guanabara Bay and utilized it as a resting, feeding and growing area. Among the species captured, Stephanolepis hispidus, Lagocephalus laevigatus, Sphoeroides greeleyi, Sphoeroides testudineus, Sphoeroides tyleri, Chilomycterus reticulatus and Chilomycterus spinosus were categorized as marine estuarine opportunists, and Aluterus heudelotii and Aluterus schoepfii were classified as marine stragglers. Acanthostracion sp. could not be categorized. The boom of C. spinosus indicates an ecological misbalance and must be carefully investigated.

Lumbrinerids are amongst the most abundant and diverse polychaete families in worldwide continental shelves, and have received attention recently through the description of several new species and new occurrences. Herein, a total of four lumbrinerid species are firstly reported in the eastern and southern Spanish continental shelf, extending their biogeographic distribution to the western Mediterranean Sea and increasing up to 25 the number of species known in the Iberian Peninsula coasts. New insights on taxonomy, ecological and biogeographic preferences and an updated taxonomic key for Iberian coasts and surrounding areas are also provided.

Península Valdés (PV) is the most austral calving ground for the SW Atlantic population of Eubalaena australis. Recent studies indicate that E. australis often feeds in PV mainly in late September and October. A microscopic analysis of food chitin remains found in five whale faeces was performed in the present study in an attempt to obtain baseline knowledge about trophic ecology and degree of use of plankton food available for whales in PV during spring (September–December). The remains in faeces from stranded and live individuals included copepods, other zooplankton and centric diatoms, all of which were characterized. Copepod remains were found to be dominant. Scanning electron and confocal laser scanning microscopes were used for comparative analyses between the mandibular gnathobases found in whale faeces and those obtained from preserved specimens. Mandibular gnathobases were the same in structure and morphometry as those obtained from preserved Calanus australis (copepodites 4–6). The positive relationship observed between the total length and width of the mandibular gnathobases edge of C. australis and those found in faeces allowed us to infer the developmental stages of the copepods ingested by E. australis. Our results indicate – for the first time – the relevant role of C. australis copepodite 5 as main prey for E. australis in PV during the calving season. Copepodite 5 of C. australis accumulates energy-rich lipids. This is energetically attractive for whales and it is the potential reason why E. australis feeds mainly on dense patches dominated by this developmental stage of C. australis.

Bioeroding sponges of the Cliona viridis species complex play a large role in carbonate cycling and reef health. In the present study we provide the first record and a description of a Mediterranean lineage of C. viridis (Schmidt, 1862) in the south-western Atlantic. Specimens were collected in Maricás Archipelago, Rio de Janeiro State in September 2010 by scuba diving at 10–12 m depth and deposited in the Porifera collection of Museu Nacional, Universidade Federal do Rio de Janeiro. Morphologically, the specimens presently examined are very similar to those described in the beta and gamma growth form from the Mediterranean. The Brazilian and Mediterranean specimens share large and irregular papillae over 2 cm in diameter, megasclere tylostyles up to 500 µm long and microsclere spirasters with up to five twists and 34 µm long. A Maximum Likelihood analysis of 28S rDNA of C. viridis, C. aprica, C. jullieni, C. schmidti and C. varians was performed for a genetic identification of the Brazilian specimens. The Brazilian material is phylogenetically closer to the Mediterranean C. viridis than to the Caribbean and Indian Ocean members of this species complex included in the present analysis. Our results suggest that C. viridis is a cryptogenic species with a distribution extending from the Mediterranean to the eastern Atlantic and in the SE Brazilian coast or further.

The Lusitanian toadfish, Halobatrachus didactylus, like other batrachoidids, is a benthic fish species with nesting behaviour during the breeding season. During this prolonged period it engages in mating activities and remains in the nest providing parental care. It is not known whether males feed while providing parental care but it is likely that their limited mobility may restrict their diet and influence their fitness. As a consequence, egg cannibalism could occur as a life-history strategy. The aim of the present study is to ascertain the feeding behaviour of nesting males, in comparison to mature non-nesting males, and to identify potential life-history traits related to egg cannibalism. Nest-holders were sampled from artificial nests placed in an intertidal area of the Tagus estuary, only exposed during spring low tides. The diet of nest-holders was compared with that of non-nesting mature males from the same area, captured by otter trawl. The present study demonstrates that despite their constrained mobility nest-holders feed during the breeding season, although in a more opportunistic fashion than non-nesting males. Nest-holders showed a generalist feeding behaviour, with a more heterogeneous diet. Egg cannibalism was not related to male condition, paternity or brood size but showed a higher incidence early in the season when water temperatures were lower. The results suggest a possible seasonal trade-off strategy between care and energy recovery, triggered by environmental factors, where under unfavourable conditions to sustain viable eggs the male may recover energy by eating eggs, thus benefiting future reproductive success, later in the season.

Lacydonia Marion & Bobretzky in Marion, 1874 is the only known genus in Lacydoniidae Bergström, 1914, which is composed of small polychaetes scarcely sampled. Studies on the biology and ecology of this group are rare and most species descriptions are based on one or a few specimens. There are 13 nominal species from different parts of the world. We revise herein the morphological characters used for species description on the basis of a lacydoniid assemblage collected in Campos Basin, Southern Brazil. Material was obtained in two sampling campaigns during the Project Habitats/Petrobras – Heterogeneidade Ambiental da Bacia de Campos, coordinated by CENPES/Petrobras. Lacydoniids were collected from the continental shelf, canyons and slope, at depths from 25 to 2500 m. This polychaete family is recorded for the first time in Brazilian waters, three new species are described and all others are new records to the South Atlantic. The new species are Lacydonia anapaulae sp. nov., L. brasiliensis sp. nov. and L. jacki sp. nov. Newly recorded species are L. cirrata (Hartman & Fauchald, 1971), L. laureci Laubier, 1975, L. miranda Marion & Bobretzky in Marion, 1874, L. oculata (Hartman, 1967) and L. cf. papillata Uschakov, 1958. An updated key to all described species of Lacydonia is included.

Recent studies suggest that sand can serve as a vehicle for exposure of humans to pathogens at beach sites, resulting in increased health risks. Sampling for microorganisms in sand should therefore be considered for inclusion in regulatory programmes aimed at protecting recreational beach users from infectious disease. Here, we review the literature on pathogen levels in beach sand, and their potential for affecting human health. In an effort to provide specific recommendations for sand sampling programmes, we outline published guidelines for beach monitoring programmes, which are currently focused exclusively on measuring microbial levels in water. We also provide background on spatial distribution and temporal characteristics of microbes in sand, as these factors influence sampling programmes. First steps toward establishing a sand sampling programme include identifying appropriate beach sites and use of initial sanitary assessments to refine site selection. A tiered approach is recommended for monitoring. This approach would include the analysis of samples from many sites for faecal indicator organisms and other conventional analytes, while testing for specific pathogens and unconventional indicators is reserved for high-risk sites. Given the diversity of microbes found in sand, studies are urgently needed to identify the most significant aetiological agent of disease and to relate microbial measurements in sand to human health risk.

Aglajidae is a family of tropical and temperate marine Cephalaspidea gastropod slugs regarded as active predators. In order to better understand their food habits and trophic interactions, we have studied the diet of all genera through the examination of gut contents. Specimens were dissected for the digestive tract and gut contents were removed and identified by optical and scanning electron microscopy. Our results confirmed that carnivory is the only feeding mode in aglajids and showed a sharp preference for vagile prey (94% of food items). We suggest that the interaction between crawling speed, presence of sensorial structures capable of detecting chemical signals from prey, and unique features of the digestive system (e.g. lack of radula, eversion of the buccal bulb, thickening of gizzard walls) led aglajid slugs to occupy a unique trophic niche among cephalaspideans, supporting the hypothesis that dietary specialization played a major role in the adaptive radiation of Cephalaspidea gastropods.

The amphipod genus Aoroides is reported for the first time in European marine waters. Specimens of Aoroides semicurvatus and Aoroides curvipes were collected in oyster reefs in Arcachon Bay between 2009 and 2014 and in Hossegor Lake in 2014 (SW France). Specimens of Aoroides longimerus were collected in 2013 and 2014 in subtidal slipper limpet beds and Zostera marina meadows in Arcachon Bay and in 2014 on floating pontoons in the Bay of Brest (W France). These species, native to Asia, may have been accidentally introduced in Arcachon Bay and Hossegor Lake with oyster transfers and in the Bay of Brest through both oyster transfers and shipping.

Reproduction, diet and growth of silky shark Carcharhinus falciformis in the eastern Arabian Sea are described based on 473 specimens collected from the gillnet-cum-longline landings at the Cochin fisheries harbour during 2012–2014. The reproductive biology of 215 males and 258 females was examined while 113 stomachs were sampled to study the diet. The von Bertalanffy growth parameters estimated using length-based models were asymptotic length (L ∞) = 309.80 cm, growth coefficient (K) = 0.10 year−1 and age at zero length (t 0) = −2.398 year. The sex ratio was significantly skewed to females. Seasonality in reproduction was not evident and in males, sexual maturity was attained at 201–223 cm total length (L T) with the size at maturity (L T50) occurring at 217.0 cm, whereas in females sexual maturity was attained at 224–231 cm L T and L T50 occurs at 226.5 cm. In total 114 embryos, in the length range of 12.2–65.1 cm were recovered from 15 pregnant females. Numbers of embryos in females were in the range of 3–13, averaging 7.6. Silky sharks of the eastern Arabian Sea feed primarily on swimming crab Charybdis smithii, with juveniles feeding principally on swimming crabs, while adults feed on actively swimming prey like squids and teleost fishes. This preliminary information on the reproduction, diet and growth should be useful to identify management strategies for silky sharks in the eastern Arabian Sea.

The force required to dislodge mussels from the substrate is known as attachment strength. This feature has been mostly studied in mytilids inhabiting the intertidal of consolidated rocky substrates, whereas it has been less studied in sedimentary substrates. The aim of this study was to evaluate the attachment strength and the number of byssal threads of Brachidontes rodriguezii in two sites with mobile substrates in San Antonio Bay, Argentina [Punta Verde (PV) and Punta Delgado (PD)]. PV has relatively higher current velocities and coarser grain size than PD. Along coastal line transects at two different levels of the mid-intertidal of each site, the attachment strength was measured. The number of byssal threads in collected mytilids and the weight of the sediment adhered to them were recorded in the lab. The attachment strength, the number of byssal threads and the sediment adhered to the byssus differed significantly between levels and sites. Mytilids from the mid-level of both sites where the density was relatively lower, had a significantly greater number of byssal threads and higher weight of sediment adhered. This study reveals that a high amount of coarse sediment adhered to the byssus affects the attachment strength of B. rodriguezii in ecosystems relative to unstable substrates. We underline the importance of mobile substrates in understanding attachment features (attachment strength and byssal threads) of mytilids in this unstable ecosystem.

The emergence of metagenomics-based approaches in biology has overcome historical culture-based biases in microbiological studies. This has also enabled a more comprehensive assessment of the microbial ecology of environmental samples. The subsequent development of next-generation sequencing technologies, able to produce hundreds of millions of sequences at improved cost and speed, necessitated a computational shift from user-supervised alignment and analysis pipelines, that were used previously for vector-based metagenomic studies that relied on Sanger sequencing. Current computational advances have expanded the scope of microbial biogeography studies and offered novel insights into microbial responses to environmental variation and anthropogenic inputs into ecosystems. However, new biostatistical and computational approaches are required to handle the large volume and complexity of these new multivariate datasets. While this has allowed more complete characterization of taxonomic, phylogenetic and functional microbial diversity, these tools are still limited by methodological biases, incomplete databases, and the high cost of fully characterizing environmental biodiversity. This review addresses the evolution of methods to monitor surface waters and characterize environmental samples through the recent computational advances in metagenomics, with an emphasis on the study of surface waters. These new methods have provided an abundance of opportunities to expand our understanding of the interaction between microbial communities and public health. Specifically, they have allowed for comprehensive monitoring of bacterial communities in surface waters for changes in community structure associated with faecal contamination and the presence of human pathogens, rather than relying on only a few indicator bacteria to direct public health concerns.

A study of an inshore southern North Sea population of lesser weever, Echiichthys vipera, on the Suffolk coast, England, found this small, abundant, benthic fish to reach an age of 15 years and suffer an adult mortality rate of only 0.23 y−1. The maximum length observed of 195 mm Standard length (SL) (225 mm total length, TL) was the greatest yet reported and many individuals >140 mm SL (163 mm TL) were caught between 2009 and 2012. Previous studies have reported a maximum of 160 mm TL and a von Bertalanffy asymptotic TL of 150.3 mm. Age structure analysis showed that recruitment into the local inshore Sizewell population continued until 5 or more years of age. A 6 year age of recruitment corresponds to the age when they have been reported to have disappeared from offshore locations and previously assumed to have died from old age. Regular seasonal changes in local abundance were observed with peak captures during May, presumably caused by seasonal immigration, followed by a summer minimum and a second, more variable, maximum in early autumn before the winter minimum. The winter minimum in captures may be due to either inactivity or offshore migration. Lesser weever has evolved a long-lived, slow growing, life history strategy unusual for small benthic fish in the southern North Sea. By spending long periods hidden in sand, using venom for defence and remaining inactive for an extended period each winter, lesser weever has adopted a strategy which favours high survival and increased longevity.

Clarification of the life-history traits of a symbiont and its host is necessary to evaluate the relationship between them. Stylochoplana pusilla, a polyclad, inhabits the mantle cavity of the eulittoral snail Monodonta labio. This study elucidated the life-history traits of S. pusilla relative to those of M. labio in a tide pool, which retained seawater, and a boulder shore, which was dry at low tide, in Mutsu Bay, northern Japan, from 2010 to 2012. In these habitats, S. pusilla was semelparous with a 1-year life cycle; it reproduced in midsummer and inhabited the shell of M. labio except for the early juvenile stages, which were planktonic. More juvenile S. pusilla newly settled on hosts in the tide pool than on the boulder shore, however, their survival rate was higher on the boulder shore compared with the tide pool. The growth rate of juvenile S. pusilla was higher in the tide pool than on the boulder shore. The higher growth rate of S. pusilla at the tide pool suggested that they were more actively feeding. Stable isotope analysis showed that S. pusilla acquired food resources outside the host snail both in the tide pool and on the boulder shore. Thus, it was likely that S. pusilla engaged in feeding outside the host snails but resulted in lower survival rates at the tide pool. These results suggest that S. pusilla is semi-free living and uses M. labio as a refuge in the eulittoral zone for protection against desiccation.

Stomach contents of six striped dolphins taken as by-catch in the swordfish fishery in the eastern Mediterranean Sea off the Turkish coast were examined. In total, 29 taxa were identified to species or family and 1777 individual food items (1394 bony fishes, 289 cephalopods, 94 crustaceans) were counted. Diaphus spp. and Ceratoscopelus maderensis were the most remarkable ones, as they accounted for 70.45% of the total number of fishes. Onychoteuthis banksii, on the other hand, was the only cephalopod species found in all stomach content analyses and represented 38.06% of the total number of cephalopods. Bony fish species: Myctophum punctatum, Notoscopelus elongatus, Electrona risso, Sudis hyalina, Moridae sp., Phycidae sp., Sternoptychidae sp. and cephalopods: Pterygioteuthis giardi and Chtenopteryx sicula were reported the first time in the stomach contents of striped dolphin in the Mediterranean Sea.

Two new species are described from the Patagonia coast of Argentina, South Atlantic, and written keys to both genera are given. Chaetonema patagonica sp. nov. can most easily be differentiated from the other four species of the genus by the amphid shape and by the absence of a precloacal organ. Admirandus sanjuliensis sp. nov. is characterized by position of the Demanian pores, one preanal and two postanal, the configuration of pre- and postcloacal papillae and setae and by having the shortest stoma in the genus.

The Indonesian archipelago is a ‘hotspot’ for invertebrate biodiversity (‘Coral Triangle’). In this area of ‘peak’ biodiversity, the origins of this high species diversity have often been debated. Xestospongia testudinaria is one of the sponge species that dominates coral reef sponge communities in this region. The role of the so-called ‘giant barrel sponge’ for the reef ecosystem has been studied repeatedly, as have its various bioactive compounds. However, the genetic variation of this iconic sponge in the region remains unknown. We investigate over 200 barrel sponge samples from Indonesia, and neighbouring as well as more distant localities (Saudi Arabia, Tanzania, Thailand, Taiwan, Java, Sulawesi and the Great Barrier Reef, Australia) using the mitochondrial cytochrome oxidase subunit 1. We compare our results with those from the studies on the congeneric barrel sponges Xestospongia muta from the Caribbean, and Xestospongia bergquistia from the Indo-Pacific, and observe a high degree of overlapping haplotypes between the three barrel sponge species, likely indicating the presence of ancestral polymorphisms. We discuss the implications of these findings to better interpret the phylogeography of barrel sponge taxa in the Indo-Pacific.

As an inherent function of a community, body-size spectrum has been increasingly used as a useful indicator in global ecological research. The colonization dynamics of biofilm-dwelling protozoa with regard to body-size spectrum were studied based on a 1-month baseline survey in coastal waters of the Yellow Sea, northern China. Samples were collected at time intervals of 1, 3, 7, 10, 14, 21 and 28 days from depths of 1 and 3 m. A total of seven body-size ranks were identified based on a trait hierarchy. The individual abundance of the protozoa at each body-size rank was well fitted to the logistic model equation. The body-size spectra showed a clear shift in probability density during the colonization period at both depths. The multivariate approach demonstrated that the temporal dynamics in body-size spectra of the protozoa may be divided into initial (1 day), transitional (3–7 days) and stable (10–28 days) stages during the colonization period. These results provide useful information for ecological research and monitoring programmes using biofilm-dwelling protozoa in marine ecosystems.