In April 2000 a massive recruitment of the barnacle Semibalanus balanoides was observed in the Clyde Sea. At one location 700 cyprids 1−1 of this species were recorded. This is ∼3500 times more abundant than previously recorded, and resulted in metamorphosis of some cyprids whilst still in the plankton, as well as massive settlement, with recruits found on adults and in the splash zone. The maximum density recorded was 109 settlers cm−2. Over the next 60 d mortality averaged 85%, resulting in a mean density of 8.4 recruits cm−2 in June 2000. Recruitment varied spatially at the km and m scale (site, shore height) but there was no evidence that it was affected by the presence of adult conspecifics.

In cartilaginous fish, holocephalians and elasmobranchs, the endolymphatic system of the inner ear generally communicates with the exterior via the endolymphatic ducts. The openings of the ducts on the dorsal side of the head were known already by eighteenth-century anatomists (Retzius, 1881). In certain elasmobranchs mineral particles from the environment pass into the inner ear through the ducts. Stewart (1906) described presence of sand grains in the membranous labyrinth of the shark, Squatina. Nishio (1926) found black volcanic particles of varying sizes in the endolymphatic duct, the sacculus and the lagena of Squatina angelus and the ray, Torpedo ocellata, from the gulf of Naples.

I have studied the inner ear of two species of electric rays, Torpedo nobiliana and T. marmorata. Considerable amounts of fine sand grains are found in the endolymphatic system of both species. The mineral particles are kept together by a gelatinous material or occur free in the endolymph. The size of the sand particles varies between 10 and 400μm. The grains are white or transparent, yellow, brownish or black. Mineralogical analysis with a polarizing microscope reveals that 85–90% of the particles consist of quartz, 5–10% of calcium carbonate and less than 5% of an unidentified opaque mineral, possibly corroded felspar. The grains are irregular with rounded or sharp edges. They differ in appearance from the round or lens-shaped concentrically layered aragonite octoconia found in the labyrinth of most elasmobranchs (Retzius, 1881; Nishio, 1926). The present findings seem to be consistent with the results by Stewart (1906) and Nishio (1926) suggesting that certain psammophilous elasmobranchs lack the ability to produce calcium carbonate otoliths and compensate for this by uptake of sand grains through their endolymphatic ducts.

The three-dimensional coral scaffolds formed by the skeletons of the cold-water corals Madrepora oculata and Lophelia pertusa represent an important deep-sea hard substratum and create an optimal shelter for a rich associated fauna in which the contribution of Porifera has still not been fully considered. The taxonomic analysis of sponges collected from two Sardinian canyons (Nora and Coda Cavallo, 256–408 m) and associated with the dead coral matrix resulted in 28 species, including new records for the Mediterranean Sea, Italian fauna or Central Tyrrhenian Sea. In addition, for many species this is the first finding associated with the coral framework or the first documentation of the in situ morphology. The taxonomic comparison with sponge assemblages associated with coral frameworks from Santa Maria di Leuca, Strait of Sicily and Bari Canyon, gave the opportunity to evaluate the similarities among geographically separated banks. Overall, the percentage of exclusive species (recorded only in one site), is very high (81%) and only one species is shared by all four sites, suggesting a low connectivity among the sponge communities. The percentage of shared species is higher for the Maltese community, supporting the role of the Sicily Channel as a crossroads between the communities of the eastern and western Mediterranean basins. Here, 55% of the sponges associated to the coral framework are also reported in shallow-water coralligenous assemblages, indicating a high bathymetric connectivity as well as an ecological plasticity allowing these species to occupy a wide range of small, dark refuges.

Muscle receptor organs (MRO) are present in the abdomen in a wide variety of higher Crustacea (see review by Alexandrowicz, 1967), though most experimental work on these organs has been carried out on representatives of only the Astacura and Palinura, in which the anatomy is relatively uniform. In the very varied group Anomura, they have been reported from among the Galatheidea, Thalassinidea and Paguridea (Alexandrowicz 1952b; Pilgrim, 1960); in the latter paper, they were shown to have properties physio-logically similar to those of the Astacura and Palinura, with slowly- and fast-adapting components. Stretch sensitive organs also occur in the thorax of many forms, but are of two distinct types there. In the posterior thorax are MRO comparable with those of the abdomen, i.e. comprising receptor cell, specialized muscle and a complex innervation of excitatory and inhibitory nerves as well as sensory fibres. In the more anterior thorax are the relatively very simple N-cells, whose dendrites spread among the fibres of non-specialized muscle and which are not known to possess any accessory innervation (Alexandrowicz, 1952a).

The settlement and recruitment of the small brachyuran crab Halicarcinus planatus from the central area of Golfo San Jorge, south-western Atlantic Ocean, was studied. Three different artificial collectors were evaluated: smooth-surface panels, panels covered with synthetic lawn and ballasted plastic boxes filled with remains of fishing nets. In addition, plankton samples were taken monthly and water salinity and temperature were recorded. Between July 2006 and June 2007, the collectors were deployed monthly in the subtidal zone of two nearby localities and collected two months later. The recovered crabs were classified into four stages: settlers, recruits, advanced juveniles and mature crabs. There were differences in the presence of stages among collector types and seasons but not between localities. Settlers and recruits were abundant on the panels with synthetic lawn, while late juvenile and mature females were more frequent in the boxes. Larval stages occur between July and February, and only zoeas I and II were found. The males, which were only represented by early juveniles, were exclusively found on the panels with synthetic lawn, from where they would subsequently migrate to cryptic habitats such as the holdfast of Macrocystis pyrifera. Settlement occurs between September and April. Settlers showed a peak in abundance during November–December, while the recruits showed two peaks, one in December and the other in February–March. For late juveniles, the maximum abundance was recorded in April–May. Ovigerous females were found between May and September, when the experiment ended. Settlement and recruitment of H. planatus in Golfo San Jorge occur over a prolonged period. Individuals may undergo shifts in microhabitat use during this period, probably related to the search for food and shelter, and avoidance of predation and cannibalism.

The object of this short paper is to describe a number of fishes exhibiting interesting abnormalities. It will be seen from the list given below that several of the specimens to be described were sent to the Laboratory on the personal initiative of gentlemen to whom I express my thanks. I am also greatly indebted to Dr. H. A. Harris and the staff of the X-ray Department of the Institute of Anatomy, University College, London, for the beautiful radiograms they supplied.

Anonyx sarsi (Crustacea: Amphipoda) is a widely distributed scavenger and predator in shallow waters of northern seas. It was caught, often in large numbers, in baited traps in the intertidal in Iceland, especially during mid-winter. Although hitherto only sporadically recorded from the intertidal, the species is undoubtedly among the most important carrion feeders there, and probably an important predator as well.

Many Thecosomata (Gastropoda) produce an aragonite shell and are potentially threatened by the increasing ocean acidification. Information about these species is very important for future monitoring of the fate of this group. This paper investigates the distribution, species composition and trophic role of Thecosomata along a transect from the coast into the open ocean off Walvis Bay, Namibia, in September 2010 and January/February 2011. Twenty species were detected, but three taxa (Limacina bulimoides, Limacina inflata and Desmopterus papilio) dominated the community with more than 80% of the total standing stock. Diel vertical migration was observed for both Limacina taxa with higher concentrations in surface waters during night. Desmopterus papilio revealed almost no day/night differences. The highest diversities and abundances were detected at the slope and offshore stations, indicating the oceanic preference of this group; some taxa aggregated at the shelf–open ocean interface. δ15N measurements confirmed the first trophic level of this group; however, significant differences were detected between seasons with higher values in February 2011. This can be related to differences in seston values as the primary food source. Possible biogeochemical causes for these differences like an exhaustion of the nitrate pool or denitrification processes under suboxic conditions are discussed.

Four species of Pinnotheridae inhabit European marine waters, Afropinnotheres monodi, Nepinnotheres pinnotheres, Pinnotheres pectunculi and Pinnotheres pisum. For these four species there are data available on the morphology of their larval stages as well as DNA markers. This information has allowed us to detect some larvae in plankton samples from the Gulf of Cadiz (SW Iberian Peninsula) that do not belong to any of these European pinnotherid species and to be confirmed by DNA barcoding. In this study these findings are shown as a case of early detection of a newly introduced and unknown species in European marine waters.

Styela mammiculata breeds during the summer, probably in August and September. Some eggs are self-sterile. Embryos show a yellow crescent of presumptive muscle cells. The larvae hatch by means of an enzyme. The larval sensory apparatus includes a large unicellular otolith and a small ocellus, which is composed of a single pigmented retinal cell and a single lens cell.

Bopyrids are highly modified epicaridean isopod ectoparasites with the adult females showing extreme specialization of body form when compared with free-living isopods (Shiino, 1965). The smaller males are similar to free-living isopods, retaining the basic cryptoniscus larval form (Naylor, 1972), and are typically found in the brood chamber of the female or attached to the ventral surface of the female's pleon (Salazar-Vallejo & Leija-Tristán, 1989).

Whilst examining the branchial morphology of the upogebiids, Upogebia stellata (Montagu), Upogebia deltaura (Leach) and Upogebia pusilla (Petagna) as part of a wider study of the physiological ecology of thalassinidean mud-shrimps, some shrimps were observed to have a branchial gall (distended branchiostegite) containing a bopyrid parasite. In this short note we add to the previous records of two bopyrid species and briefly discuss the host/parasite relationship.

Parasitized material examined: U. stellata (three males, two females) collected subtidally using an anchor dredge from White Bay, Isle of Cumbrae, Scotland (55°48'N 4°55'W) at depths of 25–30 m. A single male specimen of U. deltaura was caught using a box corer from the Irish Sea (54°7'N 3°27'W). Upogebia pusilla (one male, one female) were collected intertidally from the Arcachon Basin, France (44°40'N l°10'W) by Professor J.P. Truchot. Prior to examination, the mud-shrimps were preserved in 10% buffered formalin, the parasites removed, rinsed with distilled water and transferred to 70% ethanol. Some preserved material was also available from the Robertson Collection housed at the University Marine Biological Station Millport.

Parasitized mud-shrimps had an enlarged branchial chamber, or branchial gall, a result of branchiostegite deformation caused by the presence of the parasite. When the parasite was removed from the branchial chamber, the gills appeared splayed and flattened but showed no other signs of disturbance or damage.

Killary Harbour is a fjord or sea loch on the west coast of Ireland. With the growth of aquaculture the harbour has become the site of both raft mussel cultivation and more recently, salmon farming. The successful management of these resources requires a detailed knowledge of the harbour's hydrography and ecology. In 1980/1 an extensive survey of the harbour was made. Papers dealing with primary productivity (McMahon & Patching, 1984) zooplankton (Ryan et al. 1986) and the biology of mussels (Rodhouse et al. 1984 a, b, 1985) have already been published. In this paper, we describe the phytoplankton of the harbour and factors which influence distribution and growth.

Sand sole, Solea lascaris, were collected along the Portuguese coast, between October 2002 and July 2003, to examine feeding habits, age and growth and sexual cycle. The most important prey items were Mysidacea, Amphipoda and Polychaeta. Differences in diet according to season and length size were found: Amphipoda were very important in diet during winter, while Echinodermata were consumed mostly in summer; smaller individuals feed on Amphipoda while larger feed on Decapoda. Age of S. lascaris was determined from sagittae otoliths. The length of fish analysed ranged from 61 mm to 340 mm. The von Bertalanffy growth equation parameters differed significantly between sexes (L∞ = 342.3 mm, k = 0.50, t0 = −0.87 and L∞ = 264.5 mm, k = 0.82, t0 = 0.13, females and males, respectively). The highest values of the gonadosomatic index were obtained in winter and spring, when the highest proportion of individuals at spawning stage was recorded.

1. Measurements of hydrogen ion concentration, of phosphate concentration, and of temperature all show at certain seasons a well-marked gradient from surface to bottom. The upper 10–20 metres is more alkaline, notably depleted of phosphates and warmer.

2. Settled summer weather and deep water, free from irregularities of the bottom, favour the formation of such a gradient. Its breaking up is occasioned by wave action and the cooling of the surface water in autumn.

3. Thermal stratification in the English Channel arises at each station, and is not due to the inflow of warm over colder water.

The material upon which the following account of the development of P.canaliculata is based was mainly obtained in 1902 when working in the Laboratory at Plymouth. The larvæ were first noticed, and their identity suspected, in April of that year, and identification was made certain by keeping the larvæ in the “mysis” stage until they moulted into the post-larval form, some individuals being kept also through several subsequent moults. The intermediate stages were all taken from the plankton, since I was unable to hatch the larvæ from the egg. The only egg-bearing female seen at that time was taken on the Eddystone Ground on April 29, and her eggs were so far advanced that, although she was unfortunately killed, a few larvæ escaped from the eggs and made it possible to obtain some idea of the structure of the first zoæa.

During a short stay in Plymouth during April, 1922,1 was able not only to pick out a few more specimens from the plankton then brought in, but also, by working through a large number of preserved plankton samples, to obtain a considerable amount of additional material, mainly of later stages. A few specimens have also been found in samples of plankton from the North Sea preserved at the Fisheries Laboratory at Lowestoft, for the loan of which I am indebted to Mr. A. C. Hardy. But the larvæ of this species are much rarer in the North Sea than in the neighbourhood of Plymouth, where they are quite common.

As part of the programme of study of the geology of the western approaches initiated at Bristol by Prof. W. F. Whittard (Whittard, 1962) information has been accumulated concerning the distribution and nature of the metamorphic rocks exposed in a series of inliers between Start Point in the east and Dodman Point in the west.

Early dredgings in this area were described by Worth (1908). Six core samples and two dredgings of metamorphic rocks are listed by Hill & King (1953). Mica schist in situ is recorded by Holme (1953). Various cruises in R.V. ‘Sarsia’ from 1957 onwards have yielded seventeen cores and further dredged samples. Additional material, collected from the exposed parts of the Eddystone reefs or obtained by diving at critical localities, has become available through the kindness of members of the staff of the Marine Biological Laboratory at Plymouth.

Sixteen cores and eight dredged samples serve to demarcate an area of schistose rocks, extending some 24 miles from east to west and 7 miles in maximum width from north to south, off the southernmost part of Devon (Fig. 1). These rocks, with an exception to be noted, compare closely with those exposed on land, between Bolt Tail and Start Point, south of a well defined east-west boundary (Ussher, 1904; Tilley, 1923). There are examples of quartz-muscovite-chlorite schists precisely like the Start Mica-schists and Bolt Mica-schists described by Tilley. Albite porphyroblasts, in a rock dredged near East Rutts (Fig. I, 1262) which is transitional to Tilley's ‘schists of composite origin’, show well the contorted swarms of carbonaceous inclusions which he describes (1923, p. 180).

Last autumn the occurrence of a small Siphonophore in the produce of the surface tow-nets attracted my attention. I first noticed it in the contents of a small net, worked five miles south of the Eddystone, on September 12th, and afterwards it was obtained in great abundance close to the. Plymouth Breakwater, and even inside the Sound. It was brought in numbers to the Laboratory almost every day up to about the middle of October, but after the end of that month it was not seen again.

Coastal ecosystems are highly complex and driven by multiple environmental factors. To date we lack scientific evidence for the relative contribution of natural and anthropogenic drivers for the majority of marine habitats in order to adequately assess the role of different stressors across the European seas. Such relationship can be investigated by analysing the correlation between environmental variables and biotic patterns in multivariate space and taking into account non-linearities. Within the framework of the EMBOS (European Marine Biodiversity Observatory System) programme, hard bottom intertidal communities were sampled in a standardized way across European seas. Links between key natural and anthropogenic drivers and hard bottom communities were analysed using Boosted Regression Trees modelling. The study identified strong interregional variability and showed that patterns of hard bottom macroalgal and invertebrate communities were primarily a function of tidal regime, nutrient loading and water temperature (anomalies). The strength and shape of functional form relationships varied widely however among types of organisms (understorey algae composing mostly filamentous species, canopy-forming algae or sessile invertebrates) and aggregated community variables (cover or richness). Tidal regime significantly modulated the effect of nutrient load on the cover and richness of understorey algae and sessile invertebrates. In contrast, hydroclimate was more important for canopy algae and temperature anomalies and hydroclimate separately or interactively contributed to the observed patterns. The analyses also suggested that climate-induced shifts in weather patterns may result in the loss of algal richness and thereby in the loss of functional diversity in European hard bottom intertidal areas.

The results of an investigation into coelenteron content of the Antarctic sea anemone Urticinopsis antarctica Carlgren, 1927 are presented. Remains of invertebrate animals and fishes were found in the gastrovascular cavity of anemones. Some of them were damaged by digestion and were considered as food items of U. antarctica. These items were molluscs Addamussium colbecki (Smith, 1902), Laevilacunaria pumilia Smith, 1879, Eatoniella caliginosa Smith, 1875 and one not strictly identified gastropod species from the family Rissoidae; a crinoid from the family Comatulida; sea-urchin Sterechinus neumayeri Meissner, 1900; ophiuroid Ophiurolepis brevirima Mortensen, 1936 and a fish Trematomus sp. In contrast to the prey mentioned above, three specimens of amphipods Conicostoma sp. were not destroyed by digestion. They may represent commensals, which live in the gastrovascular cavity of the anemone.

Suspensions of heart-body tissue and of coelomocytes in solutions of porphobilinogen produced uroporphyrin. This affords additional evidence for the haematopoietic function of the heart-body, and for the view that the free porphyrins found there and in the haemoglobin-containing coelomocytes are formed by these tissues' own activity in haem synthesis.