Horizontal and vertical distribution of cephalopod paralarvae (PL) from the Mesoamerican Barrier Reef System (MBRS) in the Western Caribbean was studied during two oceanographic cruises in 2006 and 2007. A total of 1034 PL belonging to 12 families, 22 genera, 24 species, 5 morphotypes and a species complex were identified. Abralia redfieldi, Onychoteuthis banksii and Ornithoteuthis antillarum were the most abundant taxa. The taxonomic identification from these three species was corroborated with DNA barcoding (99.8–100% of similarity). Paralarvae of Octopus insularis were reported for the first time in the wild. Most PL occupied the Caribbean Surface Water mass in the 0–25 m depth stratum. Largest paralarval abundances were related to local oceanographic features favouring retention such as the Honduras Gyre and Cozumel eddy. No day-night differences were found in PL abundance, although Abralia redfieldi showed evidence of diel vertical migration. Distribution of PL in epipelagic waters of the MBRS was probably related to ontogenetic migration, hydrographic features of meso and subscale, and to the circulation regimes dominated by the Yucatan Current. The MBRS represents an important dispersion area for PL, potentially connecting a species-rich Caribbean community with the Gulf of Mexico and Florida waters.

High definition video from a towed camera system was used to describe the deep-sea benthic habitats within an elongate depression located at the western margin of Rockall Bank in the Hatton–Rockall Basin. At depths greater than 1190 m, an extensive area (10 km long by 1.5 km wide) of what appeared to be reduced sediments, bacterial mats and flocculent matter indicated possible cold-seep habitat. Plumes of sediment-rich fluid were observed alongside raised elongate features that gave topographic relief to the otherwise flat seafloor. In the deepest section of the depression (1215 m) dense flocculent matter was observed suspended in the water column, in places obscuring the seabed. Away from the bacterial mats, the habitat changed rapidly to sediments dominated by tube-dwelling polychaete worms and then to deep-sea sedimentary habitats more typical for the water depth (sponges and burrowing megafauna in areas of gentle slopes, and coral gardens on steeper slopes).

We investigated the habitat use and feeding ecology of 10 cetacean species encountered along the south-eastern coast of Brazil (24–26°S) using carbon (δ13C) and nitrogen (δ15N) stable isotopes. Hierarchical cluster analysis distinguished two main groups based on their isotopic patterns. One group included migratory baleen whales (Megaptera novaeangliae and Eubalaena australis) with the lowest δ13C and δ15N values, reflecting baseline isotopic values of their Subantarctic feeding grounds and consumption of lower trophic level prey. Resident species and those occasionally occurring in Brazilian coastal waters highly differed from the migratory whales in their isotopic values. In this group, Tursiops truncatus had the highest δ13C and δ15N values, indicating coastal habits and relatively higher trophic position. Similar δ13C values were observed in Sotalia guianensis, Pontoporia blainvillei, Orcinus orca and Steno bredanensis. However, the former two species had lower δ15N values than the latter two, indicating different trophic positions. The relatively lower δ13C values observed in Stenella frontalis suggest greater influence of pelagic prey in their diet. Furthermore, the lower δ13C values observed in Delphinus delphis and Balaenoptera edeni were associated with upwelling events that occur along the region, affecting the isotopic values of their main prey. Juvenile M. novaeangliae had higher δ13C and δ15N than the adults, which may indicate feeding in areas with different isoscapes and consumption of pelagic schooling fish with relatively higher trophic levels than krill. This study provides preliminary information that are useful to understand the habitat use and coexistence of cetacean species occurring in south-eastern Brazil.

The mating pattern of Littoraria flava, a typical grazer snail of the supralittoral zone and sometimes the midlittoral zone of boulder shores in tropical and sub-tropical regions, was examined to determine the occurrence of size-assortative mating and sexual selection on size. We also evaluated its reproductive behavioural mechanisms, as well as their implications for the evolution of the species. The population was investigated from May 2001 through April 2002, on an artificial rocky shore composed of a boulder wall at Flexeira Beach, Itacuruçá Island, Rio de Janeiro, Brazil (22°56′S 43°53′W). The current study showed that: (1) copulating pairs were observed only from November through March, indicating seasonal reproduction of the population; (2) linear correlation between sizes of copulating mates were weak but significant, characterizing assortative mating by size; (3) there was sexual selection for female size, i.e. large females were favoured as mating partners over small ones; however, sexual selection on size was not observed among males; (4) there were significant positive correlations between male and female shell sizes and the copulation time; (5) there were significant differences in copulation time among different types of copulating pairs; and (6) mating females were significantly larger than non-mating females, while there were no differences between the sizes of mating and non-mating males, indicating differential sexual selection between sexes. These findings may contribute to the evolution of sexual dimorphism in this species. Male choice behaviour plausibly explains the assortative mating and sexual selection on female size of Littoraria flava. As males chose larger mates because they benefit reproductively therefore large females have increased chances of mating and fertilization (sexual selection for size). Further evidence suggests that large females are more successful than small females in carrying out mating, because large females remain in copulation for a longer time than do small females.

Long-term monitoring programmes of a comparatively small area complement larger scale, but temporally limited surveys and can provide extensive datasets on seasonal occurrence and fine-scale habitat use of multiple species. A marine mammal monitoring programme, involving year-round, land-based observations, has been conducted in Broadhaven Bay candidate Special Area of Conservation, north-west Ireland, during 2002, 2005 and 2008–2011. Nine cetacean and two seal species have been recorded, with grey seal, harbour porpoise, common and bottlenose dolphins, and minke whale present throughout the year. Generalized additive models, taking into account observer effort, sighting conditions (sea state) and interannual variation, did not reveal any significant seasonal patterns in the occurrence of grey seals, bottlenose dolphins and minke whales. On the other hand, common dolphin presence in Broadhaven Bay was highest during autumn and winter. Bottlenose dolphins could be separated spatially from both common dolphins and minke whales in a classification tree by their preferential use of the shallower inshore areas of the bay (<30 m depth). However, common dolphins and minke whales, which occurred mainly in the deeper outer section of Broadhaven Bay, could not be spatially distinguished from each other, and grey seals were distributed over the entire bay. Broadhaven Bay represents an important marine mammal habitat with respect to overall species diversity and the regular occurrence of bottlenose dolphin, harbour porpoise, grey and harbour seals (all listed under Annex II of the EU Habitats Directive).

Two taxa of commercially exploited cuttlefish, Sepia officinalis and S. hierredda, are compared for the first time on the bases of quantitative morphology and allozyme polymorphisms. Morphometric measurements and meristic counts of selected soft and hard (cuttlebone) body characters, with allozyme electrophoretic analysis are used. Samples were obtained from north-west Iberian Peninsula and Senegalese waters (West Africa). Significant differences in mantle width, arm and hectocotylus length, numbers of rows of reduced suckers on the hectocotylus and in most cuttlebone measurements were found. Canonical discriminant functions of cuttlebone measurements for males and females were calculated. Allozyme electrophoresis for 33 presumptive loci showed low levels of genetic variability and 13 diagnostic loci between the two Sepia taxa. The genetic identities (I) in pairwise comparisons of populations of both taxa were I=0·582–0·596, which are typical values for congeneric species. These congruent morphological and genetic results strongly suggest that S. officinalis and S. hierredda are different species.

Several aspects of the biology of Opisthoteuthis calypso were studied based on 38 individuals (23 males, 14 females and 1 indeterminate) retrieved from bottom trawls fished at 871 to 1420 m depth in the Sardinian Channel (central western Mediterranean). Data on full maturity of females are presented for the first time for this species. Information on the distribution, size, structure and fecundity for both sexes is provided, and the biological characteristics of the Sardinian samples are compared to those of other Mediterranean and Atlantic samples. Morphological variability and the peculiar structure of the shell and beak are reported and discussed. Molecular DNA sequences were obtained and compared with sequences available for the genus Opisthoteuthis.

Temperature is one of the most influential factors for the sexual maturation of fishes, but understanding of the extent to which temperature affects the maturational schedules is limited in multiple-spawning fishes over a protracted season. This study examined the effect of temperature on sexual maturation of Japanese anchovy Engraulis japonicus siblings under high and low temperature regimes on different birthdates. The maturation probability differed between the two temperature regimes. Specimens in high temperature regimes matured at much smaller size and younger age than their counterparts. Also, a significant difference in the maturation probability between sexes was found at low temperatures, but not at high temperatures. Our findings show that temperature affects the maturational schedules of siblings of Japanese anchovy, suggesting that the size and age at sexual maturation could differ among cohorts, even in a given sampling location and/or year.

All the currently known species of Guitarra with spiny isochelae have been reviewed by SEM: Guitarra fimbriata, Guitarra indica, Guitarra bipocillifea, Guitarra abbotti and Guitarra laplani. A new species from Namibia;Guitarra flamenca, is described, which is characterized by bipocilla-like spiny isochelae similar to those of Tetrapocillon atlanticus, placochelae in two different morphological categories and very robust megascleres. After a revision through SEM of the specimen of Guitarra fimbriata var. indica, it clearly belongs to Guitarra flamenca sp. nov. The morphological variability of the placochelae and the spiny isochelae across the Guitarra-species has been analysed and the main parameters useful to differentiate species are highlighted.

Semele solida and Tagelus (Tagelus) dombeii are two tellinacean bivalves which coexist in the lower intertidal zone of a sandflat in south-central Chile but follow different feeding strategies. Wheras T. (T.) dombeii is a suspension-feeder, S. solida is a facultative deposit-feeder. In this study, digestive gland indices and reproductive cycles were described in relation to annual food availability and related to their feeding modes. Results showed that gonadic index cycles were similar for both species, with highest values being observed during the spring when water temperature was still on the rise and microflagellate and centric diatom density was at its peak. However, histological analyses indicated that the spawning period of T. (T.) dombeii extended from November 1995 to March 1996 and from August 1996 to January 1997, whereas S. solida presented a continuous spawning period that extended from September 1995 to December 1996. Results suggest that extended spawning throughout the winter by S. solida is a consequence of its ability to feed on bottom deposits when food in suspension is low.

The Gammarus here described is found in Chelson Meadow, a large tract of reclaimed land lying near the mouth of the Plym, and protected from the tidal water by an embankment. The land is drained by ditches, which empty into the Plym at low water by means of sluice-gates. The sea-water enters in volume only at the highest tides over the top of the sluice-gates, but there is a constant slight infiltration of salt water through the embankment.

Trichosphaerium sieboldi is a marine amoeba with a cosmopolitan distribution. The ability of three strains, from different geographical regions, to digest a range of macroalgae was investigated. Prior to these experiments, methods were developed for the axenic cultivation of T. sieboldi. Algae included Fucus vesiculosus, F. spiralis, Laminaria digitata, L. saccharina, Mastocarpus stellatus, Palmaria palmata, Porhyra sp., and Ulva sp. All were degraded with equivalent ease; typically 50% of the tissue biomass was removed within seven days. The wall of this amoeba was studied to obtain clues on how a protist could be digesting macroalgal tissue. The fibrous nature of the outer cell wall presumably allows the wall to part and remesh during consumption of large particles. It is suggested that during digestion of macroalgae, the wall is parted to enable digestive enzymes to be localized along the surface of the seaweed wall, effectively forming an ‘enzyme pocket’. Trichosphaerium has both polysaccharidases and glycosidases, notably glucosidase, cellobiosidase, mannosidase and fucosidase. These enzymes work in concert to facilitate the breakdown of the complex polysaccharides found across the range of seaweeds used. These studies suggest that T. sieboldi could be a primary invader of seaweeds in the field. They also suggest that some protistan groups may be important in the degradation and recycling of algal material in coastal waters.

The feeding ecology of the southern thorny skate, Amblyraja doellojuradoi, on the Argentine Continental Shelf was evaluated using generalized linear models. Amblyraja doellojuradoi preyed mainly on crabs (85.41% index of relative importance (IRI)) and to a lesser extent on polychaetes (4.98% IRI), teleosts (3.28% IRI), isopods (2.03% IRI), other crustaceans (1.52% IRI) and other invertebrates (2.78% IRI). As individuals increased in size, the consumption of crabs also increased and the consumption of polychaetes and other invertebrates decreased. The study area was divided into a northern (36°–43°S) and a southern (43°–50°S) region. Regarding the latitude of capture, it was observed that A. doellojuradoi mainly fed on crabs in the north and on fish, isopods and other crustaceans in the south. Females of A. doellojuradoi had a stronger preference for fish and isopods than males. As to sexual maturity, immatures fed more on polychaetes and other crustaceans than did mature. The ontogenetic change in feeding habits could be attributed to body size and an increasing ability to capture larger prey, rather than to food availability. However, this point cannot be confirmed because little is known about the benthic fauna of this area.

This study aimed to examine the responses of RNA/DNA ratio in Perna viridis under different nutritional status via both field and laboratory studies, and hence evaluate the usefulness of this ratio as a rapid growth biomarker in the mussels. First, the effects of size (small: 30–40 mm; medium: 40–50 mm; large: >50 mm) and tissue type (adductor muscle, foot, gill and hepatopancreas) on the RNA/DNA ratio were investigated in P. viridis collected from three different sites with different degrees of eutrophication in Hong Kong waters. Across all sizes, the mussels collected from a fairly ‘eutrophic’ mariculture zone had significantly higher RNA/DNA ratios in their gills than those from the other two relatively clean sites. The RNA/DNA ratio in small mussels was generally higher than in medium and large individuals, though such a size effect significantly interacted with tissue type and site. Second, we conducted a 10-day comparative laboratory study to elucidate the influence of starvation and feeding on the RNA/DNA ratio in the mussels. We observed that both hepatopancreas and foot muscle generally exhibited significant and rapid response to such a short-term starvation or food addition. The present results confirmed that the RNA/DNA ratio in P. viridis is a sensitive biomarker to gauge their growth and general health condition in accordance with food availability and/or eutrophication condition.

Serial-section electron micrographs have been obtained of the phagocytosis of Prochloron cells by amoebocytes of the ascidian Lissoclinum voeltzkowi (Michaelsen). This may answer the hitherto puzzling question of how the host tunicate benefits from photosynthetic symbionts situated in an excurrent water flow.

The aim of the paper has been to treat the data of the Plaice experiments on Growth and Maintenance, carried out at Cawsand and Lympstone during 1929 and 1930, in a statistical manner. The experiments for each sex, year and place have been resolved into experiments with an average plaice during the “average” 14 days of the third growth season. Growth and food-percentage indices have been provided and a fairly high degree of correlation between food and growth has been indicated, and shown to be uniform for the sexes. Regression coefficients indicating the facility with which food is utilised for purposes of growth have been worked out and have been shown to vary with place and year, but not with sex. Maintenance demands have been evaluated and shown to be slightly greater in males than in females. The diminished demands during winter months have also been evaluated. The outstanding features of the results are the distinct differences shown between the Cawsand and Lympstone plaice, which differences it is suggested arise out of size differences to a large extent.

In 1866 Hincks described the hydroid Cuspidella humilis: later, in his History of the British Hydroid Zoophytes (1868, p. 210), he added two further species to the genus, C. grandis and C. costata. At that time the reproduction of Cuspidella was not known.

Metschnikoff (1886, p. 83 and Taf. V, Fig. 1) described the development of the eggs of Laodicea cruciata and reared them to the hydroid stage. These had sessile hydranths and elongated polyps with ten slender tentacles, long and short alternating. Metschnikoff remarked on their similarity to Cuspidella.

The coast of Aragua is a home of bottlenose dolphins (BND), Atlantic spotted dolphins (ASD) and fishermen (FIS) from four towns. A photo-identification study was carried out on BND to estimate their home ranges. From 2004 to 2008, 100 field surveys were carried out along 30 km of coastline (92.12 km2). In each sighting of BND, information regarding date, time, latitude/longitude and photographs were registered (ASD and FIS were registered without photography). The data were analysed using a Geographic Information System to estimate Minimum Convex Polygon (MCP) and Fixed Kernel (FK) at 95%. The home ranges of BND were estimated for seven individuals. This included three females (29–31 sightings) with estimated areas ranging from 33.90–39.90 km2 with MCP (36.79–43.31% of the study area) and from 80.47–101.31 km2 with FK (109.97–104.26%). For the remaining four dolphins (14–20 sightings) the estimated areas ranged from 9.67–22.34 km2 (MCP), the predominant depth of these home ranges varied from 51–100 m (χ2 = 24.5, df = 2, P = 4.785 × 10−6). For the pods of ASD the estimated area ranged 75.23 km2 with MCP (81.66%) and 119.86 km2 with FK (130.11%) with predominant depths of 101–200 m (χ2 = 24.5, df = 2, P = 4.785 × 10−6). The area used by FIS ranged 93.27 km2 by MCP and 228.49 km2 by FK. Finally, the overlap area of BND, ASD and FIS ranged 24.75 km2 (26.86%). We point out this locality presents important oceanographic and ecological aspects which deserve to be the subject of application of management plans for the conservation of its habitat and species.

A brief reference to the state of opinion concerning the water movements off S.W. England is made. Then a series of Drift Indicator records relating to 28 days of observation at 6 fathoms depth from the Seven Stones Lightvessel is presented and discussed. An overall flow of water towards the S.E. quadrant and of speed approaching 2 miles per day characterised the entire period. The residual current as worked out for the individual records, displayed considerable variation in speed and direction—setting as frequently towards the northern half of the compass as towards the southern, but more frequently towards the eastern half than towards the western half. There were pronounced changes in the wind speed and direction, and it appears as though the wind can drive the water at 6 fathoms depth towards a point to the right of its own direction, no matter from which of the four quadrants it blows.

In May, 1933, during routine gonad examinations, a hermaphrodite specimen of Echinocardium cordatum was observed. It was collected in the sandy beach of Port Erin Bay at low water of ordinary spring tides, and was 4.7 cm. in length, which corresponds, in a normal specimen, to an age of about four years. The external colour was dark, although not more so than in other specimens in the batch, but the gonad was exceptionally pigmented—almost black. In this locality the colour of the test and gonad becomes progressively darker with increasing age, and affords some measure of the latter.

The specimen was examined within half an hour of being collected, and portions of the gonad were fixed within ten minutes of being opened, so that fertilization and segmentation could not have advanced in the laboratory to the stage found. Smears from the gonad showed ova, of which about 50% were ripe, together with ripe spermatozoa. The gonoduct contained ripe ova, together with segmenting ova and early embryos. Figure 1 is a photograph of the contents of the gonoduct, taken immediately after opening, and showing ova with a four-cell stage and a blastula. Cultures were set up in sterile sea-water, from the contents of the gonoduct, and also from the gonad itself, as well as a control fertilization from normal urchins, and from all of these normal early plutei were reared. Those cultures from the hermaphrodite specimen did not, however, develop much further, possibly owing to premature fertilization in the abnormal conditions in the gonad.