Elytra of polynoids show two kinds of luminescent responses, viz. a quick flash (duration ca. 100 msec) and prolonged glow (duration 0·25–10 sec). Quick flashes are produced by nervous excitation; prolonged glow responses accompany or follow fast repetitive flashing, or are elicited by strong electrical stimuli. Anaesthetized isolated elytra still give the prolonged glow response when electrically stimulated. Facilitation is also evident in consecutive glow responses. From these various observations it is concluded that the prolonged glow response can be produced by fast repetitive nervous excitation or by direct electrical excitation of the photocytes. The occurrence of facilitation in glow responses of anaesthetized elytra raises the problem whether the same phenomenon in consecutive normal flashes may be due to intracellular changes taking place within the photocytes.

A one-year study of the reproductive biology of a population of Diopatra marocensis at the Villaviciosa estuary, northern Spain, was undertaken with emphasis on brooding behaviour, larval development and gametogenesis. Field observations together with a histological study of monthly collected individuals revealed that the population was iteroparous, reproducing annually during a short breeding season extending from March to June. The study demonstrated that all individuals of the population at Villaviciosa estuary were producing at the same time eggs and sperm providing for the first time evidence for the occurrence of simultaneous hermaphroditism in D. marocensis. Mature sperm was of the ent-aquasperm type and was stored in modified nephridial chambers in brooding individuals. In the latter, eggs in advanced cleavage phases were also observed inside the coelom suggesting that fertilization was internal. Eggs in late vitellogenesis presented micronucleoli in the periphery of the nucleus, a phenomenon reported previously for few polychaete species. Pure males and females were never found. It is here suggested that in D. marocensis population size may influence sex allocation and that under conditions of low population densities simultaneous hermaphrodites may be favoured. The study of the larval development confirmed the direct development reported previously for populations of Morocco and Portugal. Further results suggest consumption of nurse eggs and adelphophagy by developing larvae.

Two samples of Neanthes succinea (Frey & Leuckart 1847) from the Mediterranean Sea were investigated. Twenty-one loci were analysed; seven of them were polymorphic in both populations. The level of heterozygosity was 2.2% and 4.4% in populations from the Tyrrhenian and Adriatic coasts respectively. The value of Nei's genetic identity index (1=0.965), together with the mean F(IT) (=0.350), shows that the samples can be considered reproductively isolated populations. F-statistics indicate that ME-1 is the discriminant locus between populations.

The rate of excretion of ammonia by Nassarius decreases progressively during starvation. Both Nassarius and Buccinum exhibit a transient peak of ammonia excretion some 16–48 h after a meal. In Nassarius the length of the delay between feeding and maximum ammonia excretion depends on the duration of prior starvation.

Biological and physical evidence suggests that the area south-west of Ireland is one of loss from the Celtic Sea. In winter the shelf water there may cascade to 400 m. or even deeper (Cooper & Vaux, 1949). All the evidence suggests that new water enters the Celtic Sea and English Channel over the continental slope between Ushant and the Sole submarine promontory 250 miles to the west. No evidence exists that the Atlantic surface waters are ever rich enough to account for the enrichment of the English Channel observed in the nineteen-twenties. Although the existence then of sufficiently rich oceanic surface water cannot be excluded, it is much more probable that the enrichment was brought about by some form of upwelling. The cause of this is thought to be composite. Only a few times in a century may the component phenomena work together to produce the maximum effect. Each component needs separate study.

The Porcupine Abyssal Plain in the north-eastern Atlantic Ocean is subject to periodical deposition of phytodetritus and has a highly diverse benthic fauna dependent on this source of organic matter. Among the most abundant species from the northern study site of the Institute of Oceanographic Sciences Deacon Laboratory (IOSDL) at ~48°50′N 16°30′W, 4850 m, is Iosactis vagabunda gen. nov., sp. nov. (Cnidaria: Actiniaria, Iosactiidae fam. nov.), a small endomyarian sea anemone. The fact that this species is a burrower, with a smooth, unspecialized column, and a rounded aboral end provided with a central pit, makes it stand out from the other families of endomyarian anemones and prompted the establishment of the new family Iosactiidae. There is evidence that the closest relatives of the new family are the ‘deep water actiniids’ (e.g. Bolocera, Liponema, Leipsiceras), and the Andresiidae. Long-term in situ time-lapse photographs indicate a unique behaviour of this anemone in that it moves out of its hole at times, presumably exhibiting a hemisessile lifestyle in this peculiar abyssal habitat.

There has existed in the past, and still does exist, considerable confusion both in the question of a satisfactory basis for the classification of ascidians and that of the validity of many species.

The principal orders and families are fairly stereotyped, and confusion and divergent opinion is mainly confined to the internal classification of the various families. These differences have a twofold origin, in that classifications have been constructed by various authors on three distinct bases, and that it is very difficult to distinguish between structures which are similar through relationship and those which are similar through convergent or parallel development. Further difficulty arises from the fact that authors describing a new species with a view to fitting it into one particular classification, have often given insufficient details for its accurate inclusion in another scheme. There is also divergent opinion as to the correct nomenclature that should be employed, but with that this paper is not concerned.

Lights were attached to the headline of a bottom trawl during a series of tows at 1000 m depth in the Rockall Trough (north-east Atlantic). There was no significant difference in the overall numerical abundance of demersal fish between the trawl catches with light and the controls with no light. A principal components analysis based on the total fish catch between the experimental and the control stations showed no segregation. At the individual species level significant differences in catch rate were found for eight species. These are discussed in relation to the small amount of available information on the visual systems of deep-sea demersal fish and their diet.

The intertidal insect Anurida maritima (Apterygota: Collembola) has a circatidal rhythm of locomotory activity on the soil surface which was observed during both the day and the night. The main function of this activity was foraging for food. When a superabundant food supply was provided on the upper shore, this completely repressed the usual migration to the lower shore. There was a clear rhythm in feeding activity which was highest shortly after the sea uncovered the insects' shelters and declined rapidly during the intertidal period. The circatidal rhythm of locomotory activity persisted in the laboratory in constant light for seven days (15 cycles). A free-running rhythm underlying the degree of aggregation was also detected.

An accessory organ of the circulatory system has been found in Sepia officinalis and Loligo forbesi, situated on the inner surface of the mantle around the posterior pallial vessels. It is spheroidal in shape and consists chiefly of muscle fibres forming bundles anastomosing with one another, most of them taking a general circular course round the artery and the vein. In Sepia the muscle bundles are more loosely arranged, being imbedded in connective tissue of soft consistency; they are not continuous either with the musculature of the vessels or with that of the mantle, and show certain structural differences from them. The nerves approaching this organ from various directions carry elements of two systems: (a) fibres given off by the branches innervating the neighbouring mantle muscles; (b) elements of the vasomotor system; these are 3 trunks consisting of fibres of small calibre and containing groups or rows of ganglion cells. One of these trunks associates with one of the main mantle nerves, another runs through the retractor muscle of the branchia. Within the accessory organ they intermingle with the motor fibres, but the nerve bundles passing to the posterior pallial vessels consist of fibres of the vasomotor system only; it is possible that the muscles of the accessory organ are supplied, in addition to their motor innervation, with fibres of the vasomotor system.

A specimen of the oilfish, Ruvettus pretiosus, was captured from the northern Adriatic (Gulf of Trieste) and represents the northernmost extension in range of this species in the Adriatic Sea.

Growth in Loliolus noctiluca (Myopsida: Loliginidae) in Western Port, Victoria, Australia was studied from statolith growth increments. Tetracycline staining experiments verified previous work on tropical forms of this species that showed growth increments to be deposited daily. A logistic growth function described the relationship between length and increment number. There appear to be major differences in the form of growth, longevity and life history pattern between tropical and temperate forms of this species. These are probably attributable to differences in environmental conditions.

Spectral reflectivity and transmission of the iridescent cuticle of six species of male Sapphirina (Poecilostomatoida: Copepoda) were measured by microspectrophotometry. Sapphirina angusta and S. opalina showed two spectral peaks of reflection, one at about 420 nm and the other at wavelengths longer than 750 nm. Sapphirina auronitens and S. gastrica had dominant peaks at wavelengths longer than 500 nm. Sapphirina ovatolanceolata had peaks between 430 and 600 nm, while S. metallina had various peaks along a wide range of wavelengths. The peaks at the longer wavelength in S. angusta and S. opalina may be related to the red pigments in the subcuticular layer of the species, or a result of a second-order effect of the multilayer system. The spectra of transmitted light were complementary to those of reflected light, indicating that the iridescence is caused by the interference of light by the integumental multilayer structure. The present results are also consistent with the hypothesis that the iridescence has a role in increasing the contrast of males against the ambient light conditions in the daytime distributional depth of the species.

In connexion with a study of plankton-benthos interrelationships off the coast of Northumberland, an apparatus was designed for the collection of plankton in the immediate vicinity of the sea-bottom, a layer usually missed by ordinary plankton sampling gear. The present account is a brief description of this apparatus, together with some notes on its handling at sea and the work carried out with it on board the Dove Marine Laboratory's boat, the Pandalus II.

I was fortunate in having the willing co-operation of numerous people who helped in various ways, and to whom I am very greatly indebted. These included my father, Mr E. Bossanyi; Mr T. E. F. Sanderson of Eastcote, Middlesex; Prof. A. C. Hardy, Oxford University; Dr C. E. Lucas, Fishery Laboratory, Aberdeen; Prof. A. D. Hobson, Director of the Dove Marine Laboratory; Dr H. O. Bull, Assistant Director; Messrs Ellis and Co., Engineering Works, Swalwell, County Durham; the Department of Mechanical Engineering of King's College, Newcastle upon Tyne; and the entire scientific, boat and technical staff as well as research students at the Dove Marine Laboratory. Without them, the design, construction and employment of the apparatus would not have been possible.

The morphological characteristics of a new isolate of a dorso-ventrally flattened athecate dinoflagellate obtained from Hong Kong (HK) waters is described. Partial sequences of the large subunit ribosomal RNA gene were obtained and a high degree of similarity was observed with various species within the genus Karenia. Phylogenetic comparison suggested the Karenia sp. HK forms a clade with the newly described species K. papilionacea from New Zealand but not with authentic K. brevis from North America. Karenia sp. HK is the first K. brevis-like dinoflagellate characterized by molecular cladistics from the South China Sea and the results call for re-examination of the status of other K. brevis-like morphotypes described from the region.

Individuals of Lysmata wurdemanni first mature in a male phase (MP) and then change to the external phenotype of females (female-phase=FP). The FPs retain the male gonadal system and function both as male and female (simultaneous hermaphrodites). The cost of maleness to FPs on fecundity was estimated with an experiment in which the social environment (FP opportunity to function as a male) was varied. The effect of maleness on brood size (number of embryos brood−1) and frequency of spawning (interspawn interval in days) was measured in FPs maintained in different social environments (treatments) over two complete spawning cycles. In treatment 1 (isolated FP) and 2 (1 FP, 1 MP), FPs could only function as females. In treatments 3 (2 FPs) and 4 (5 FPs, 5 MPs), FPs could breed both as male and female.

Baseline brood size was described for FPs with a regression equation of brood size on FP body size (carapace length). Brood size is positively and isometrically related to FP size. Brood sizes, adjusted for FP body size using the baseline regression equation, were compared among treatments 2–4 (isolated FPs in treatment 1 did not produce fertile broods). Brood sizes were significantly greater in FPs in treatment 2 (only female breeding) than in treatments 3 and 4 (both male and female sexual function possible). However, spawning was less frequent (longer interspawn intervals) in treatments 1 and 2 than in treatments 3 and 4. Total fecundity over a four-month breeding period was estimated with a model using mean treatment brood sizes and interspawn intervals. Estimates of total fecundity in FPs functioning both as male and female were much lower, in spite of somewhat more frequent spawning, than those in which male function was not allowed. The ‘price’ (cost) of maleness on fecundity appears to be compensated by the high selective advantage of male mating ability in the simultaneous hermaphrodite FPs of Lysmata species.

This study analyses the possible relationships between body size and length of cnidae from different tissues of the sea anemone Oulactis muscosa. We describe the cnidom, providing new qualitative and quantitative data. Our description adds spirocysts for tentacles and acrorhagi, and is more precise about the ranges and types of basitrichs, microbasic b-mastigophores, and holotrichs. We distinguish two types of holotrichs in the acrorhagi, and differentiate between microbasic b-mastigophores and basitrichs in the actinopharynx and mesenterial filaments. A relationship between cnida length and body weight was not demonstrated. The results are based on a complete account of cnida types from all tissues, and considering the great number of capsules measured (5400) and the modern statistical tools employed, we think that a normal distribution of cnida lengths is uncommon, perhaps refuted. This finding is very important when a quantitative analysis of cnidae is necessary and an adequate statistical tool must be used. We have shown that generalized linear models are an alternative and therefore analyses can be done with parametric methods despite the non-normal distribution of cnida size. The use of these statistical tools should be generalized since appropriate package for analyses (like the R package) are available from the web and the obtained results are robust and powerful.

The occasional reports of butterflies sighted at sea or landing on ships many kilometres from the nearest land indicate the transport of insects by wind from terrestrial to marine environments. However, the frequency with which insects are blown out to sea, the abundances of airborne insects over and on the surface of the sea, the eventual fate of these insects and their possible ecological roles are rarely considered (Bowden & Johnson, 1976).

The minke whale (Balaenoptera acutorostrata) is a widespread, opportunistic species showing spatial and seasonal variations in diet according to local availability of prey. Although previous research has been conducted on the foraging strategies of this small rorqual whale, in terms of prey aggregation and assimilation, relatively little has been published on the foraging association of this species with coastal seabirds. Over the past five years, minke whales occurring along the outer coastline of the southern Moray Firth in north-east Scotland during the summer and autumn months have been recorded foraging in the presence of seabirds, such as kittiwakes (Rissa tridactyla), herring gulls (Larus argentatus), guillemots (Uria aalge) and shearwaters, which form dense feeding rafts at the water's surface. The formation of bird rafts notably occurs independently of the presence of B. acutorostrata, believed instead to be the successive result of prey concentrated at the surface by predatory schooling fish from below rather than by activities of the whales themselves. In this area of the North Sea, schooling mackerel (Scomber scombrus) constitute the most significant component of the summer fish biomass and are believed to perform the role of compacting targeted sandeel (Ammodytes spp.) prey into concentrated bait balls almost exclusively. The resulting ball of prey is consequently available to the foraging whale, which can be seen opportunistically utilizing successive bird rafts rather than expending unnecessary energy corralling the Ammodytes prey by traditional, active entrapment methods. The role of the mackerel in increasing both the rate and density of sandeel ball formation (as indicated by the presence and activity of associated bird rafts) is therefore thought to be very significant in this inshore Scottish location. Changes in oceanographic variables such as water temperature have been directly correlated with the migration of S. scombrus. The observed inter-annual variability in B. acutorostrata distribution in the outer Moray Firth may subsequently be related to the respective distribution and abundance of these migratory, pelagic fish species.

Shipworms (teredinids) are highly specialized marine bivalves that consume terrestrially derived wood. Changes in environmental variables may result in shipworms spreading into the Baltic Sea – which would have devastating consequences for maritime cultural heritage and submerged wooden structures. We investigated the distribution and abundance of the shipworms Teredo navalis and Psiloteredo megotara along the Swedish coast in 2006–2008, and compared our findings with data collected at partly the same locations in 1971–1973. Wooden test panels were submerged in near-surface waters at 18 harbours. The presence of shipworms was determined by X-ray radiography of each panel. Sea surface temperature and salinity data were analysed to investigate whether any changes in distribution were correlated to changes in environmental variables. We found that past and present distributions of T. navalis were similar – indicating that no range expansion of shipworms into the Baltic Sea has taken place the last 35 years. The abundance of T. navalis was similar between decades at all investigated sites except two (Arild and Barsebäckshamn), where abundances were higher in 2006–2008. The abundance of T. navalis varied along the coast and was positively correlated to mean sea surface salinity, but not to mean sea surface temperature (2006–2008 data). The distribution and abundance of P. megotara were similar during the two study periods with only single observations at a few sites. In conclusion, we found no evidence of range expansion of shipworms along the Swedish coast.