The diet of common wolffish Anarhichas lupus from the North Sea is described, from a total of 143 wolffish stomachs, of which 112 contained food. The main prey were crustaceans and molluscs, together representing almost 70% of diet by relative frequency of occurrence in stomachs. Wolffish >55 cm preferred polychaetes and gastropods while wolffish <55 cm preferred sea urchins and brittle stars. The occurrence of empty stomachs was significantly less in spring than in summer or in autumn/winter. Meal size was lowest in winter and highest in spring. These data reflect a period of low food intake in winter during spawning and tooth replacement, followed by a recovery feeding episode in spring.

Ascension Island in the South Atlantic Ocean is renowned for its globally-important nesting population of green turtles (Chelonia mydas) that has been the subject of long-term research. By comparison, very little is known about the apparently small population of hawksbill turtles (Eretmochelys imbricata) that have been recorded in its waters, thousands of kilometres from known nesting beaches. Here, we collate 10 years of in-water tagging data, opportunistic public sighting records and underwater observations to provide a baseline for future research, and present preliminary data on habitat use derived from two individuals fitted with GPS transmitters. Although public sightings were inevitably biased towards popular recreation areas, the resulting distribution suggests that hawksbill turtles occur year round in Ascension Island's waters along the entire 65 km of coastline. Hawksbills were observed feeding on benthic algae and encrusting sponges, and were frequently seen scavenging on fish discards around the Island's pier at night aided by anthropogenic lighting. Between 2003 and 2013, 35 turtles were captured, measured, tagged and then released. Curved carapace lengths ranged from 33.5 to 85 cm (mean = 48.8 cm) indicating that most (if not all) individuals encountered around Ascension are post-pelagic juveniles. Four individuals were recaptured at least once giving a mean minimum residence time of 4.2 yr (range: 2.8–7.3 yr) and a mean growth rate of 2.8 cm yr−1. Turtles fitted with Fastloc™ GPS devices remained at Ascension Island for the duration of the study (>90 days) and occupied restricted home ranges with an average area of 2.5 km2 and an average ‘core use area’ (50% utilization distribution) of 0.05 km2. Together, these results suggest that Ascension Island serves as a mid-Atlantic developmental habitat for benthic-feeding, juvenile hawksbill turtles on extended oceanic migrations before recruiting to their adult foraging grounds, likely to be located in Brazil or tropical West Africa.

A new species of the genus Tambja is described from the western Atlantic on the coast of Brazil. To date, the genus Tambja was represented in the Atlantic Ocean by nine species but only three of them have been recorded from the western Atlantic: T. gratiosa from the Gulf of Mexico, T. divae from Brazil and T. oliva from the Caribbean coast of the Isthmus of Panama. Tambja stegosauriformis sp. nov. is easily distinguished from all its congeneric Atlantic species of the genus by having very well developed light blue tubercles scattered on the yellowish-orange ground with an elongate crest behind the gill until the end of the tail. The anterior margin of the notum is very wide and elevated and it extends into a kind of lapel around the rhinophores. This peculiar external morphology and its conspicuous coloration characterize this species.

The presence of a diverse range of epibionts was found on Pagurus bernhardus from the west coast of Scotland. The invertebrate species found on the shell inhabited by the crab were the hydrozoans Hydractinia echinata and Dycorine conferta, the cirripeds Balanus balanus and Balanus crenatus, the polychaetes Hydroides norvegica, Pomatoceros triqueter and Circeis armoricana, and the molluscs Hiatella arctica and Anomia ephippium. On the crab were observed the polychaete Circeis armoricana and the amphipod Podoceropsis nitida. In addition, on the gastropod shells occupied by P. bernhardus, ciliate protozoan species were found attached to the hydrozoan Dycorine conferta, this being hyperepibiosis. These ciliates were 6 suctorian (Conchacineta constricta, Corynophrya anisostyla, Actinocyathula homari, Actinocyathula crenata, Acineta sulcata and Acineta corophii), and one peritrich species (Zoothamnium sp.). This is the first time that this hyperepibiosis was observed. In contrast to the epibiont communities observed in previous surveys in the same sampling area, basibiont specimens without D. conferta did not show ciliate epibionts. The ciliate epibionts also were not present on the surface of the shell and crab in specimens with D. conferta; they only appeared in hyperepibiosis on the surface of the hydrozoan. The spatial distribution and abundance of the invertebrate epibiont species were analysed, as well as the morphology, taxonomy and distribution of the ciliate hyperepibionts.

Upon infesting the hermit crab Pagurus proximus the parasitic barnacle Peltogaster reticulatus typically forms a single externa on each host. In vivo, histological and histochemical study revealed that most P. reticulatus with a single mature externa also exhibited three or four primordial externae and several buds of earlier developmental stages. It is shown that stolon buds and primordial externae in P. reticulatus internae intensively express alkaline phosphatase activity, the classical histochemical marker for mammalian embryonic stem and primary germ cells. Ovaries of the most developed primordial externae were filled with growing oocytes, so the process of oogenesis begins in the externa rudiments of P. reticulatus before the externae appear on the surface of the host body. Since the interna, which is connected to the mature externa, also integrated three or four additional primordial externae and several earlier buds, P. reticulatus, a non-colonial species based on the common presence of a single externa in each host, appears to have a hidden colonial organization at the parasitic stage of its life cycle.

The objective of the study was to investigate the seasonal variations in proximate and fatty acid composition of wild sobaity (Sparidentex hasta) for a one-year period during (i) pre-spawning (October–December), (ii) spawning (January–March), (iii) post-spawning (April–June) and summer (July–September). Five male and five female fish were collected from market each month and used for the study. Skinless fillets from both sides of sobaity were taken, chopped, minced, frozen and freeze dried. Freeze-dried ground male and female fish samples were pooled separately and homogenized for proximate composition and fatty acid analysis. The results of the investigation showed that the muscle proximate composition and fatty acid profile of sobaity differed significantly (P < 0.05) among different seasons with the highest muscle lipid during the pre-spawning and spawning season. Palmitic acid (C16:0) was the most dominant muscle fatty acid followed by oleic acid (C18:1n-9). The muscle docosahexaenoic acid (DHA, C22:6n-3) levels in pre-spawning and spawning seasons were significantly (P < 0.05) higher than those in other seasons. A good n-3/n-6 ratio (2.26–3.11) and the higher DHA levels (10.16–11.47%) observed in muscles during the pre-spawning and spawning season indicated a better nutritional value of sobaity at this time of the year.

A study was conducted over eight consecutive days in February 2010 in which daily variations in the vertical distributions of heterotrophic bacteria, mesozooplankton and ichthyoplankton at 1–1200 m in the South-western Atlantic Ocean were investigated. Diurnal and nocturnal samples were collected at an oceanographic station at four regional depths: Tropical Water (TW) (1 m), South Atlantic Central Water (SACW) (250 m), Antarctic Intermediate Water (AAIW) (800 m) and Upper Circumpolar Deep Water (UCDW) (1200 m). Bacterial, mesozooplankton and larval fish densities significantly differed between sample depths but not between sampling tow times. In total, 154 zooplankton species and 18 larval fish species were identified. The highest number of taxa was obtained from the night-time TW trawls. This depth zone had the highest densities of mesozooplankton, larval fish and bacterioplankton (auto and heterotrophic), associated with the highest temperature and salinity and the lowest inorganic nutrient concentrations. Two sample groups were identified based on their mesozooplankton and larval fish compositions: night-time TW and other water masses (daytime TW, SACW, AAIW and UCDW). Thirty-two indicator species were detected in night-time TW. The copepod Nullosetigera impar was, to the best of our knowledge, identified for the first time on the Brazilian coast. Our results showed significant variability in the abundance and vertical distribution of mesozooplankton, bacterioplankton and larval fish along the water column in an oceanic area. We have provided new data and insights on the composition and vertical distribution of mesozooplankton, larval fish and bacterioplankton in deep waters in the South-western Atlantic Ocean.

The investigation of the trawling-grounds in Start Bay, Torbay, and Teignmouth Bay, which had been previously investigated in 1895–8 by Messrs. Stead and Holt, was resumed by the Marine Biological Association in 1901, under authority from the Devon Sea Fisheries Committee.

This is the first report on the presence of basking sharks Cetorhinus maximus in Galician waters (north-west Iberian Peninsula) from sightings, strandings and incidental catches by fishing gear. Morphometric, biological, geographic and temporal data on 19 basking sharks recorded from 1988 to 1998 are presented. Average total length is 401·4 cm. Male:female ratio is 0·6. Seventy per cent of records are from incidental fishing catches in bottom gill nets. Approximately 74% of sharks were recorded during February, March and April, which may suggest that the species occurs seasonally in this area.

An array of nano-scale protrusions, called the nipple array, is found on the body surface of various invertebrates, and this structure is believed to decrease light reflectance and water wettability on the surface in the terrestrial environment. However, its potential functions have not been well studied in aquatic environments. Clavelina spp. are colonial ascidians that have the nipple array on their integumentary matrix (i.e. tunic). We examined the physical properties on the surface of the tunic of C. cyclus and C. obesa, such as hardness, wettability and refractive indices, to evaluate the functional importance of this structure. The tunic cuticle of both species was covered with the nipple array, and the cuticle of C. cyclus was bent into folds forming parallel plications. The Clavelina tunic was very soft and had high bubble- and oil-repellency. The refractive-index deviation between the tunic and seawater was 0.07–0.095 for 589-nm light (D-line). Rigorous coupled wave analysis (RCWA) showed that the nipple array slightly reduced reflectance on the surface and the parallel plications reduced the reflectance still more. The nanoimprinted plates imitating the parallel plications have higher bubble repellency and lower reflectance than the flat plates. These findings support the functional importance of the plications as well as the nipple array.

The chain catshark (Scyliorhinus retifer) is a member of one of the most well studied groups of elasmobranchs (Order: Carcharhiniformes), yet its feeding strategy is unknown due to the inaccessible deep water environment in which it lives (greater than 200 m). To investigate the feeding biology of captive S. retifer, high-speed videography was used to document the kinematic events during capture of two differently sized fish pieces, ‘large’ (scaled to the mouth width), and ‘small’ (scaled to one-half the mouth width). Despite a significant delay in the timing of select kinematic variables for large food captures, a multivariate analysis of the feeding behaviour indicated that overall, food capture kinematics and strike behaviour in S. retifer were not statistically different between large and small items (MANOVA, Wilks' Lambda P =0.598, df=4,24). Food capture in S. retifer was suction-dominant, with items being drawn into the mouth about twice the distance that the predator moved. While suction-dominant food capture appears to be an advantage to benthic predators, it contrasts sharply with the phylogenetic position of S. retifer among several ram-feeding carcharinoid sharks including Cephaloscyllium ventriosum, a member of the same family (Scyliorhinidae). Thus, feeding mode in carcharinoid sharks seems to reflect their ecology and does not appear to have been phylogenetically constrained.

Seasonal changes in spatial structure of biomass of submerged aquatic vegetation (SAV) and environmental variables were evaluated in Celestun Lagoon, an estuarine habitat in Mexico. Geostatistical techniques were used to evaluate spatial autocorrelation and to predict the spatial distribution by kriging. The relative contribution of 11 environmental variables in explaining the spatial structure of biomass of SAV was evaluated by canonical correspondence analysis. Spatial partitioning between species of SAV was evident: the seagrasses Halodule wrightii and Ruppia maritima dominated the seaward and central zones of the lagoon, respectively, whereas the green alga Chara fibrosa was constrained to the inner zone. The spatial structure and seasonal variability of SAV biomass were best explained by organic carbon in the sediments, salinity and total suspended solids in the water column. Analysis at different spatial scales allowed identifying the importance of spatial structure in biotic and abiotic variables of this estuarine habitat.

It is well known that vision is the main physical factor governing the formation and maintenance offish shoals, and that, in general, shoals break up when the light intensity falls below a certain level. Breder (1929, 1942), Newman (1876), Parr (1927, 1931), and others, have shown this by laboratory experiment.

During a commercial fishing voyage to the Barents Sea it became possible, by means of a recording echo-sounder, to study the shoaling behaviour of cod in deep water relative to light intensity. The observations were made aboard the Hull trawler Lancella whilst fishing in a depth of 110 fathoms at Skolpen Bank in September 1955. For this a Kelvin and Hughes recording echosounder type MS. 24J was used, the depth range across the chart being 55 fathoms. The scale was phased so that the region between 80 and 135 fathoms deep was displayed.

In his search for evidence illustrating the botanical/zoological affinities of the sponges (Porifera), James-Clark (1867) studied a number of colourless flagellates. The genus Salpingoeca (Craspedophyceae, Christensen, 1962; cf. Chadefaud, 1960) was thus erected to comprise certain solitary, lorica-dwelling organisms, characterized by a single anterior flagellum encircled by a ‘filmy, membranous, colourless collar’ (James-Clark, 1867).

About fifty species (approximately twenty marine) are at present allocated to this genus, provided it is defined as e.g. by Norris (1965) and Bourrelly (1968) (i.e. including Lagenoeca Kent and Pachysoeca Ellis).

A growing body of literature shows that benthic communities are hierarchically structured on spatial and temporal scales. In two study locations at Helgoland (North Sea), the northern and the western locations, we: (1) investigated the variation in abundance of specific algae and invertebrates at two spatial scales; and (2) evaluated the relationship between elevation and specific species at these scales. We were also interested in using this information about the spatial pattern of individual algae and invertebrates as well as the patterns of elevation to help develop a monitoring programme of the rocky intertidal. We examined the variation of individual algae and invertebrates by means of a hierarchical nested design. Data were taken from five replicates per plot, with plots located in transects (two transects per location).

At the northern location, the highest variability in cover of most algae and invertebrates occurred at the scale separated by about 50 m (scale: transect). This was a direct result of differences between the high- and the low-shore. Most species at high-shore showed a relatively low frequency of occurrence in contrast to a highest frequency of occurence (~100%) and maximal values of cover at low-shore. However, neither a linear nor a non-linear relationship between elevation and the specific species occurred. At the western location, the highest variability in most macroalgae and invertebrates investigated was among replicates (10s of centimetres apart). No relationship between elevation and individual species occurred at this location. Macroalgae at both locations were more consistent over time than invertebrate species. Our results suggest that the relevant processes shaping the individual macroalgae and invertebrates at the Helgoland rocky intertidal vary between locations and the specific species.

The potential causes of variation in macroalgal and invertebrate species at different spatial scales are discussed and suggestions for a future monitoring programme are given. Temporal inconsistency in the spatial patterns, and the fact that some individual algae and invertebrates comprising the benthic assemblages vary at different scales, speak in favour of a multiple-scale sampling approach for monitoring change in the intertidal communities at Helgoland.

Chondrilla nucula is a morphologically simple species defined by the presence of spherasters in its skeleton. For a long time C. nucula was considered a cosmopolitan species, however, in 1999, a molecular study demonstrated the existence of a species complex with at least four cryptic species, besides C. nucula. At that time, those four new species were not formally described because the morphological differences observed did not reflect species differences and were attributed to plasticity. Since then, researchers working on Chondrilla species suggested that the skeletal organization, the distribution of spherulous cells and the type of surface should be used to differentiate species. Individuals of Chondrilla aff. nucula from one population in Arraial do Cabo, Rio de Janeiro State, Brazil, were collected monthly and analysed in order to test the validity of those three characters to separate the species of Chondrilla. Moreover, to determine if the differences in spicule dimensions previously found were seasonal, we also quantified the diameter of the spherasters throughout the year. Our results demonstrate that all analysed characters are extremely variable and that spicule size can vary even at the same locality. The present study shows the importance of testing the variability of morphological characters before describing new species. Unfortunately, until valid taxonomic characters are found, the Atlantic Chondrilla species will have to remain undescribed.

Some meiobenthic harpacticoid copepod species cannot be successfully cultured, therefore empirical models were developed to estimate their development times, using literature data, but taking into consideration several empirical rules previously formulated to model the development of planktonic copepods. The present models demonstrated the overwhelming influence of rearing temperature on egg development time, and of body length on total development time and indicate a capacity to adapt development rates to environmental temperature.

Water, carbon, and nitrogen contents were analysed in both juvenile and adult specimens of Diaphus theta, Stenobrachius leucopsarus, and S. nannochir, which are the dominant myctophid species in the subarctic and transition waters of the North Pacific. The relationship between body length and dry weight, carbon content, and nitrogen content of these three species were expressed as double logarithmic equations. The differences in chemical content among the different size-classes of each species may be associated with reproductive biology.

In earlier behavioural studies carried out at the Plymouth Laboratory, Pagurus bernhardus L. displayed no activity towards its symbiotic actinian, Calliactis parasitica (Couch) (Ross, 1960; Ross & Sutton, 1961 a). This was in marked contrast to other familiar pagurid/actinian associations, e.g. with Dardanus spp., in which the pagurid participates actively in the transfer of Calliactis to its shells (Brunelli, 1910; Faurot 1910; Ross & Sutton, 1961 b; Ross, 1970, 1974). In the case of P. bernhardus and C. parasitica, laboratory trials showed that contact of the anemone's tentacles with a shell, even an unoccupied shell or one of a living gastropod, releases a sequential behaviour pattern in which the anemone frees its pedal disc and somersaults to the shell. It has been argued (Ross, 1967) that this association exists solely because of the behaviour pattern by which C. parasitica climbs on shells.

Two ovigerous females of the processid shrimp Processa macrodactyla were caught in April 1997 at 13 m depth in coastal waters of Rota, Cádiz Bay, south-western Spain (36°36′N 6°18′W). Rearing was terminated after nine zoeal stages, when larvae moulted to the first juvenile instar. Descriptions of the appendages of every instar have been made so as to: (1) compare the larval morphology with that of other previous described known species in the genus Processa (P. canaliculata, P. edulis, P. elegantula, P. modica, P. nouveli); and (2) with those larvae not ascribed to a certain species in order to facilitate the specific identification of unknown collected planktonic larvae. When describing P. macrodactyla some characters remained, with few exceptions, invariable in their setation form ZI to ZIV or ZV, to then change and maintain until the last zoeal stage. This can be due to intermediate moults, with the result that some larvae unite the characters of Stages ZIV and ZV and others those of ZV and ZVI.