The arrangement of the ciliary sensory organs regularly arrayed on the body is re-described, and it is concluded that these are what are visible as bristles in life. On the head and tail region there are, in addition, stout single cilia, which contain multiple internal tubules, and on the head alone, there are presumed sensory cells which contain cilia within invaginations of the cell surface. Small bunches of pointed bristles occur scattered over the body surface; these are entirely distinct from the sensory cilia.

A new species and genus of brachiopod has been dredged by R.V.‘Sarsia’ on three cruises to the Western Approaches of the English Channel and two to the La Chapelle Bank region. In general appearance it closely resembles Dallina septigera (Lovén) with which it appears to have been confused by Fischer & Oehlert (1891).

In 1956 it was obtained on 13 June at position 48° 33′ N., 10° 05′ W. at a depth of 570–770 fathoms, four specimens of shell length 17–25 mm were taken together with seven D. septigera.

Morphogenetic events during the division of the marine ciliate, Euplotes vannus (Müller, 1786) Diesing, 1850 were investigated using protargol impregnation: (1) the opisthe's oral primordium develops de novo in a subsurface pouch above the marginal cirri; (2) the cirral anlagen for the frontal, ventral and transverse cirri in both dividers develop separately on the surface epi-apokinetally, cirrus I/1 and marginal anlagen for daughter cells are formed de novo separately; (3) the dorsal kinety anlagen occur in a non-typical primary pattern within the parental structures at mid-body, of which the 3 right-most ones produce the 3 caudal cirri for the proter; and (4) the opisthe acquires 2 caudal cirri from the end of the right-most 2 kineties. Based on the data available, the reasons for the variation in the number of caudal cirri in E. vannus are discussed.

The invasive species Caulerpa racemosa var. cylindracea represents a serious threat to the diversity of benthic assemblages in the Mediterranean Sea. In the present study, a removal experiment was carried out to test whether, after 18 months of C. racemosa var. cylindracea exclusion, the macrophyte assemblage resembled a non-invaded assemblage. The results show that in the assemblage invaded by C. racemosa var. cylindracea the number of species, macrophyte cover, Shannon diversity and Pielou's evenness were lower than in the non-invaded assemblage. Erect perennial species were particularly affected and other introduced species were significantly reduced or completely excluded. After 18 months of removal/exclusion of C. racemosa var. cylindracea, only partial recovery of the macrophyte assemblage could be observed. Species numbers, total cover and erect perennial species cover were still significantly lower than in the non-invaded plots. However Shannon diversity and Pielou's evenness had reached comparable levels. In contrast to native macrophytes, the total cover of other introduced species reached a level comparable to the non-invaded plots. In summary, the present study revealed that after 18 months of C. racemosa var. cylindracea exclusion: (i) only partial recovery of the macrophyte assemblage occurred; and (ii) the development of other invasive species was favoured by the absence of C. racemosa var. cylindracea (Sisyphus effect).

Sixteen sediment samples were collected from a square grid (4×4) with a horizontal distance of about 150 m between positions in Århus Bay in the south-west Kattegat (14 to 15 m water depth). Critical shear stress (τc) was measured in all samples and related to sediment parameters: grain-sizes, organic matter, water content, porosity, and chlorophyll-a (chl-a) content, in upper layers. Samples were divided into a low (A) τc group and a high (B) τc group in relation to an erosion rate. A significant (P<0·001) difference in median τc was found between groups A (0·0284 N m−2) and B (0·0380 N m−2). Average chl-a concentrations in groups A (1·4 μg g−1) and B (1·8 μg g−1) were not significantly different (P=0·47) but there was a significant and positive correlation (r2: 0·7, P<0·001) between τc and diatom film abundance. Sediment organic matter and water content were significantly higher in group B compared with A, which contradicts that watery and organic rich sediments generally exhibit low τc. This was explained by the presence of a diatom film cover on the fluff layer that inhibits the action of erosive forces. A fluff layer is characterized by a high water and organic content. The fluff layer was present in the majority of the samples but the highest average chl-a content and a significant (P=0·020) higher abundance of diatom film was observed in group B (high τc). Benthic diatoms were dominated by Haslea crucigeroides, Pleurosigma strigosum, and Bacillaris paxillifer. Spatial variability of sediment parameters was high and variability of a stability/erodibility parameter even exceeded those recorded for highly heterogeneous tidal flats. The occurrence of benthic diatoms at 14–15 m of water depth in the eutrophic Århus Bay was supposedly related to a measured increase in Secci depth in the bay and thereby increased light penetration depth.

An ecological assessment of Fecampia erythrocephala, reporting its habitat distribution, abundance, host specificity, size-specific prevalence, frequency distribution among hosts, effect on host growth, and its site specificity within these hosts is presented. At the Isle of Man and near Plymouth, Fecampia erythrocephala cocoons were generally abundant on the undersides of rocks in the Ascophyllum and Fucus serratus zones. Infected crabs were also most common in these habitats. Both Carcinus maenas and Cancer pagurus were parasitized at similar prevalences, although the former species was relatively much more common in the habitats where the worm cocoons were abundant. Fecampia erythrocephala did not infect crabs larger than 11 mm carapace width, and prevalence decreased significantly with crab size. Prevalences reached 11% in areas where cocoons were abundant. Together with the large size of these worms relative to the size of the host crabs and the observations on worm emergence, these life history features indicate that F. erythrocephala is a parasitoid of young shore crabs. Fecampia erythrocephala cocoon abundance is often high in localized areas and size-prevalence information suggests that worms mature rapidly in these crabs. This suggests that F. erythrocephala is an important contributor to crab mortality and to the ecology of shore crabs at these sites.

Twenty species of calycophoran siphonophores were identified from the central and south Adriatic Sea in spring 2002. Highest abundance and species diversity were noted at the deepest stations in the south Adriatic. Highest total abundance was found in the upper 100 m. The dominant species above 100 m were Lensia subtilis, Eudoxoides spiralis and Sphaeronectes gracilis, none of which showed diel migration. The first two species correlated significantly with the vertical abundance of microzooplankton, and the last with that of copepods. The most abundant species in the 100-400 m layer was Lensia meteori, whereas Lensia conoidea and Chlausophyes ovata were most abundant below 400 m.

The ascidian Corella inflata (Chordata, Ascidiacea) is common in many areas of Puget Sound, Washington, USA. However, it occurs only in habitats where it is protected from direct sunlight. Previous experiments with artificial lights showed that UV irradiation kills all life stages of this animal. The effects of natural sunlight exposure (measuring survival of adults, juveniles, larvae, and embryos) were compared. We partitioned the light spectrum to separate the effects of UVB, UVA, and visible light (PAR). Natural sunlight severely damaged C. inflata. Adults and juveniles died after 2-5 d. Exposed embryos failed to develop normally and larvae did not settle. As expected, UVB had significant effects, but pronounced effects were also seen when the animals were exposed to longer wavelengths alone (UVA and PAR). Thus, the distribution of C. inflata may be determined largely by exposure to light. Understanding the basic ecology of this species requires consideration of its vulnerability to sunlight damage and the effects of UVB, UVA, and PAR.

This study aimed to identify the effects of different sieve mesh-sizes on processing time, the number of species retained, diversity measures and multivariate community analysis in the North Sea. Samples were collected at 63 sites throughout the North Sea and washed through two successive sieves, 10-mm and 5-mm mesh respectively.  Processing time for whole samples (5- and 10-mm fraction) averaged 91± 25 min compared with 55±16 min for the 10-mm mesh fraction. Altogether 40% of free-living species and 9% of attached species were recorded exclusively in the 5-mm fraction. The majority of these species were rare. Spatial gradients of species diversity and community structure were identical, independent of the mesh-size used. Multivariate community analysis showed no significant difference between descriptions of community structure based on fauna from 10-mm or 5-mm mesh.  The use of coarser sieving mesh would save time and money, if the aims of an epibenthic survey were to describe broad patterns of community structure and relative diversity. It would be possible to process approximately 50% more samples, if the time saved with 10-mm mesh were allocated to additional sampling. However, if information on single species is required, then sorting with the finer sieve mesh will yield crucial information. It was decided to employ a 5-mm mesh for epibenthic monitoring of the North Sea.

Physical factors affecting the fate and functional capabilities of the pedal mucus of Patella vulgata L. deposited in the intertidal have been examined. Mucus dehydration, rehydration and degradation were assessed. Mucus dehydration is dependent on ambient wind speed, temperature and relative humidity. Of these, over naturally encountered ranges, wind speed produces the greatest water loss over a 6-h period and it is surmised that mucus deposited at mid-shore will lose >60% of its water when exposed by the tide on days when the air is not still. The more dehydrated pedal mucus is, the longer it subsequently takes when immersed to reach a fully hydrated state.

Field observations of small (<20 mm) individuals of Mytulus galloprovincialis at Littlehampton (West Sussex) on the south-eastern coast of England showed that many collected as recently dead shells had a distinctive pattern of damage around the posterior valve margins. Laboratory experiments confirmed that small Carcinus maenas (<22 mm carapace width) were capable of inflicting a similar style of damage. Small C. maenas fed successfully on a range of mussel sizes (5–20 mm shell length), positively correlated with carapace width. All used the same technique to access the bivalve prey, that is, by marginal mandibular chipping in order to achieve sufficient damage to allow insertion of a chelal dactyl between the valves. Mandibular chipping has previously been reported upon from non-chelate decapods and juvenile lobsters. The chelae of juvenile C. maenas are small and have a lower mechanical advantage than has been reported upon for adult conspecifics which, in any case, are not highly adapted for durophagy. We suggest that because of the poor mechanical performance and small gape of the chelae juvenile C. maenas behave as though they were achelate. As well as broadening our understanding of the repertoire of known feeding behaviours of C. maenas, our study may also provide an insight into the evolution of durophagy within the Decapoda.

As Moseley (1879) noted, it may be imprudent to assume there must always be a ‘reason’ for observed displays of bioluminescence. However, knowledge of the colour of the light emitted may be useful for examining some of the theories about the function of marine bioluminescence. Certainly the colour of the light is important in predicting the rate of its attenuation in sea water, and the ease of perception of the light by the organism itself, or by potential predators, prey, or mates. In addition, the colour of the light may indicate something about the compounds responsible for producing the light. The present paper presents some bioluminescent emission spectra of freshly caught organisms from the Sargasso Sea.

This study was carried out to determine the amphipod fauna in Mar Piccolo, Mar Grande and the Gulf of Taranto. Material in this study was obtained from 96 stations at different depths (maximum depth: −50 m) using various methods depending on the substrata. A total of 65 species was determined and 25 species are new records in the seas of Taranto. Microdeutopus gryllotalpa, Ericthonius brasiliensis, Monocorophium insidiosum, Elasmopus rapax, Gammarus aequicauda, Gammarus insensibilis, Leucothoe spinicarpa, Lysianassa costae and Pseudoprotella phasma were the dominant species and have been found in all areas considered. The comparison of the data shows that the area examined presents a high difference regarding biocenotic index. The highest number of species was collected in the Gulf with 1944 individuals, belonging to 58 species and 19 families, followed by Mar Grande with 1448 individuals belonging to 36 species and 11 families; finally Mar Piccolo with 698 individuals, 12 species and 6 families, in the First Inlet and 546 individuals, 18 species and 6 families, in the Second Inlet.

The production of chemicals from the brown seaweeds is one of the oldest branches of the chemical industry, having its origin as far back as 1720 when soda was first produced from kelp in France, and soon after taken up in Ireland, Scotland and Norway. Until the early nineteenth century this was the only source of this chemical on which the glass and soap industries were built up. When the cheap Leblanc soda later became competitive the industry was able ot switch to potash and iodine production, a demand for which had arisen about the same time. This industry reached sizeable proportion, as is evidenced by the fact that in 1820 more than 20,000 tons of kelp were produced in the Outer Hebrides, involving the collecting and burning of about a million tons of cast weed.

Seasonality of the reproductive cycle for Cancer pagurus was determined using three biological indicators: extruding sperm plugs (mating period), extrusion of eggs (spawning period) and presence of empty egg capsules (hatching period). Sperm plugs were found only in recently moulted females, indicating that mating coincides with moulting periods. Cancer pagurus mating indicators were observed during the summer months and into autumn; spawning occurred in winter, and broods were hatching throughout the summer into early autumn. Size at maturity, was assessed using a variety of reproductive and morphometric criteria; estimates from reproductive criteria are generally larger than those from morphometric criteria and these differences are often indicative of ‘functional’ vs ‘behavioural’ maturity. In C. pagurus, size at maturity estimates ranged from 101.6–125.0 mm carapace width (CW) in males and 110.7–147.3 mm CW in females; the sizes at functional maturity proposed are larger than those from morphometric indicators.

On the basis of extensive material from Plymouth an attempt has been made to determine the specific limits of the European species of the eolid genus Eubranchus Forbes. From a study of the living animals, jaws, radulae and reproductive systems, it is concluded that five species can be recognized as occurring commonly in Britain, Eubranchus tricolor Forbes (=Galvina viridula Bergh), E. farrani (Alder & Hancock), E. pallidus (Alder & Hancock), E. cingulatus (Alder & Hancock) and E. exiguus (Alder & Hancock). These species are all variable in coloration, but they can nevertheless be easily distinguished by coloration as well as by morphological and ecological characteristics. A further species, E. doriae (Trinchese) from the Mediterranean, was also examined and appears to be distinct. No material of Eubranchus rupiurn (Moller) and E. vittatus (Alder & Hancock) was available for examination, but these are provisionally maintained as distinct species. The European species of Eubranchus are compared with species from other parts of the world in an attempt to decide how many genera should be recognized. It is concluded that the armature of the penis and the liver branching do not form good generic characters, and that consequently Capellinia is to be regarded as a junior synonym of Eubranchus.

There is sometimes a significant bias in the sex ratio of fish caught by longline. Usually, more females than males are caught. The possible reasons for unequal sex ratios in longline catches are listed and discussed. One sex could be more common in the area where the fishery takes place because there really is an unequal sex ratio in the population or because the other sex preferentially occurs in different places. Alternatively, longline fishery might preferentially catch one of the sexes. This could be a result of size difference between the sexes and thus a different response to the given hook size or bait size. Finally, sexes could differ in their feeding behaviour. There is growing evidence that females—not only of fish—are ‘energy maximizers’: they find food faster and spend more time feeding than do males. Thus, fishing methods using bait are likely to catch a higher proportion of females than fishing methods that do not use bait.

The composition of fatty acids was studied in the mussels collected in the Mar Grande of Taranto (northern Ionian Sea) during the four seasons. Micro-, nano- and picophytoplankton abundance, biomass and composition have been also evaluated. Fatty acids compositions were investigated for lipid biomarkers to establish the contribution of phytoplankton to the mussel diet. Saturated (SAFA) and monounsaturated fatty acids (MUFA) were the most abundant components, followed by polyunsaturated fatty acids (PUFA). The seasonal variations in the SAFAs, MUFAs and PUFAs were not significantly different during the whole study period (ANOVA, P < 0.05). The most abundant identified FAs were 16:0 (27.51–33.80% of total FAs), 14:1 (3.35–9.91% of total FAs), 18:1n9 (2.92–8.87%), 16:1 n7 (4.53– 7.61%) and 24:1n9 (0.43–8.84%). The most important PUFAs were 22:2 (2.35–3.48% of total FAs) and also 18:2n-6 (1.66–2.61%). PUFAs were characterized by low percentages of n3 and n6 FAs. Analysis of specific FA markers for diatoms (16:1n7, 20:5n3), phytoflagellates and dinoflagellates (16:0, 18:4n3) showed a negligible contribution of phytoplankton to the mussel diet.

In order to assess the effect of feeding deprivation on growth and condition of field-caught newly settled juvenile plaice Pleuronectes platessa, a 3 week starvation experiment was conducted and changes in RNA/DNA ratio, Fulton's K condition index and recent otolith growth were measured. Fed ad libitum and starved fish were analysed after 0, 1, 2, 3, 4, 5, 7, 9, 14, 16 and 22 days of starvation. In parallel, field newly settled juvenile plaice were collected weekly over the settlement period (between April and May 2005) in the adjacent intertidal zone of the Canche estuary (eastern English Channel, France) and fish performances were estimated. After starvation day 4, Fulton's K condition index and RNA/DNA ratio of juvenile plaice significantly differed between treatments while recent otolith growth differed between treatments after day 9 of the experiment procedure. Results indicate that the three biological parameters are sensitive indices and can be used to accurately assess nutritional condition of wild juvenile fish. Values of 0.32 for RNA/DNA, 0.83 mg. mm−3 for Fulton's K index, and 3.99 µm for recent otolith daily growth were defined as critical threshold values below which juvenile plaice can be classified as ‘starving'. When comparing these experimental values with those from field-caught newly settled juvenile plaice, less than 1% of wild individuals can be classified as ‘starving' whatever the index. Our results suggest that feeding conditions throughout the settlement period on the Canche intertidal nursery ground are favourable to juvenile plaice development and survival, and hence to the recruitment success.

Pleuroncodes monodon, an important fishery resource and key species in the Humboldt Current Large Marine ecosystem, has a prolonged reproductive period from winter until end of summer, and during this time females incubating their embryos are exposed to seasonal variation in food availability and in temperature. Additionally, in order to ensure successful reproduction and survival of embryos, changes occur in the main internal reserves and/or sources of energy of P. monodon. The aim of this study was to determine the extent of seasonal variation (winter vs summer) in the lipid content and fatty acid composition of ovigerous females and their embryos. The results show that a higher percentage of saturated and polyunsaturated fatty acids are found in females in winter. Similarly, the composition of fatty acids in embryos found here indicates that winter embryos have more saturated fatty acids and essential fatty acids (C18:2n6cis, C18:3n6 and C22:6n3) than do summer embryos. According to PCA analysis of fatty acid profile, samples from summer may be distinguished into two isolated groups with conspicuous variations in fatty acids profile of embryo and hepatopancreas. While in winter, the opposite pattern occurs in the fatty acid profile of embryo and hepatopancreas. These variations may be related to relevant physiological processes (reproduction and growth) and of their ontogeny (development and survival of offspring). Seasonal variation in the lipid content and composition of fatty acids of P. monodon could directly impact this species’ reproduction and survival and subsequently could have consequences on the food web and fishery exploitation.