The head of the sperm whale (Physeter macrocephalus L.), which is largely snout and the crest of the skull necessary to support it, may exceed a third of the total weight and a quarter of the length of the whale. This indicates the snout has an extremely important function but few theories regarding its function take into account the overall structure, whilst the detailed structure and proportions of the adult's snout have been almost totally neglected. Similarly, consideration of the thermal properties of the spermaceti oil, which is the most remarkable component and constitutes a large proportion of the head, have been neglected in studies of function.

A new species of the genus Lucernariopsis, of the family Eleutherocarpidae, is described.It is the second species of the genus to be found in British seas and the fourth in this world-wide genus.

Concentrations of lead in the soft tissues of the deposit-feeding bivalve Scrobicularia plana have been compared with the physicochemical characteristics of sediments in 20 estuaries in southern and western England and one in north-west France. The results indicate that the biological availability of lead in the sediment is controlled mainly by the concentration of iron, and that the concentration of lead in the bivalve may be predicted from the Pb/Fe ratio in 1 N hydrochloric acid extracts of surface sediments.

The discovery of a new species of Sarsia hydroid and its medusa and a comparison of this species with Sarsia tubulosa (M. Sars) and S. loveni (M. Sars) have resolved a longstanding problem. In his detailed account of the hydroid and medusa Coryne mirabilis (now accepted as identical and synonymous with Sarsia tubulosa), Louis Agassiz (1860-2, vol. 4, pp. 189-90, 203-4, P's- 17J i8) asserted that it undergoes a change of reproduction in winter and spring. He stated that in late winter the hydroid releases medusae but that in spring the gonophores no longer develop into normal medusae, being retained on the hydranths where they become sexually mature without mouth and tentacles. He based his conclusions on a series of hydroid colonies collected on the shore. Allman (1871-2, pp. 278-9) was strongly disinclined to accept Agassiz's assertion of the specific identity of the two forms of gonophore without stronger evidence, saying that, until the two kinds were found simultaneously or in succession on one colony kept under close observation in an aquarium, the identity of the two forms could not be accepted as proved. Mayer (1910, p. 55), from personal observation of colonies collected on the coast of Massachusetts, came to the same conclusion as Agassiz, but he did not say whether he had followed the succession in an aquarium or had observed one colony throughout, and accordingly his conclusion is subject to the same criticism.

Distinctive flask-shaped cysts have been observed within the loricae of the tintinnids Favella serrata (Mobius),Helicostomella subulata (Ehrenberg), Parundella caudata (Ostenfeld) and Leprotintinnus pellucidus (Cleve) from samples taken by the Continuous Plankton Recorder. Similar cysts occur as a common element in palynological preparations of intertidal sediments from the British Isles. Encystment in tintinnids is now known for over 20 species and appears to be a more important process in the tintinnid life-cycle than previously believed. A possible relationship between tintinnid cysts and the extinct microfossil order Chitinozoa is proposed.

Patella vulgata possesses nine different pedal glands, six of which pour their secretions on to the sole. Proteins secreted by the marginal gland into the marginal groove are used for locomotion, especially when the limpet moves off following a period of adhesion. Another protein-secreting subepithelial gland, sparsely present throughout the foot, is also believed to be used in locomotion. A third gland type is present in the epithelium of the sole. The secretion of these epithelial mucocytes which is a weakly acidic muco-polysaccharide (MPS) is likely to have a locomotory function. Three other sole glands secrete highly viscous acidic MPS. Their secretions are likely to have an adhesive function. The three other glands present in the foot are contained within the side-wall. Of these, two are believed to secrete mucus to protect the animal against desiccation during emersion; and the other, present only in young P. vulgata, pours its acidic MPS secretion into the epipodial streak. This secretion consolidates debris before it is cleared from the pallial cavity; in adult animals, muscular contractions of the foot are powerful enough to clear debris without the help of the epipodial gland.

In Acmaea tessulata the six glands present open out on to the sole and correspond in position, composition and function to the six glands of the sole of P. vulgata. There are no glands within the side-wall.

This is the second of three papers describing the structure, properties and buoyancy function of the spermaceti organ of the sperm whale (Physeter macrocephalus Linnaeus 1758). The first paper (Clarke, 1978a) described the detailed structure and proportions of the spermaceti organ and related structures and considered relevant details of the blubber, skin and lungs. Here, three thermal properties of the spermaceti oil are described which are relevant to a study of the function of the oil. Finally, in a third paper (Clarke, 1978b) it will be shown that, over its great geographical and depth ranges, the whale varies considerably in buoyancy due to variations in water density and the volume of air in its lungs and it is suggested that, during dives, the whale can control its own density by changing the temperature of the spermaceti oil of the head and may attain neutral buoyancy in dives deeper than 200 m.

The gills of Patella consist of a row of triangular shaped leaflets suspended from the roof of the pallial groove. The surface of each gill is thrown into a series of transverse furrows. Tufts of cilia are irregularly distributed over the surface and generate a current of water which flows in the opposite direction to the flow of blood within. The central part of the gill comprises a large haemocoelic space traversed by trabeculae which contain muscle fibres and suggesting that the flow of blood through the gill may be under nervous control. A blood channel runs around the periphery of the gill.

The epithelial layer bounding the blood space comprises a single layer of columnar epithelial cells. The outer surface is protected by a structured mucopolysaccharide glycocalyx held in place by a dense mat of microvilli. The cells contain clearly defined mitochondria, Golgi complex, lysosomes, rough and smooth endoplasmic reticulum. In addition, the non-ciliated cells are characterized by a layer of membrane-bound granules, of unknown function, in the apical cytoplasm.

Phagocytes are frequently found associated with the basement membrane. They contain large membrane-bound granules and appear to move outwards between the epithelial cells to expel the granules at the outer surface of the gill. It is possible that the gill has an excretory as well as respiratory role in the physiology of the animal.

Observations during four dives in the submersible ‘Alvin’ in June 1976 revealed that ctenophores were the most abundant large plankters between 400–700 m. From specimens collected with a slurp-gun device, Bathocyroe fosteri gen.nov., sp.nov., a species characterized by strong lobes, large auricles and red pigmentation of the gut, is described. Few ctenophores have been collected previously from deep water, but observations from submersibles indicate that several species occur throughout the mesopelagic zone.

This paper will discuss the buoyancy of the sperm whale throughout its range and show that the whale probably has some control over its own buoyancy. Evidence will then be presented in support of the hypothesis that the whale can attain neutral buoyancy at depths greater than 200 m by control of the temperature of the spermaceti oil in its head. As a basis for this, papers describing the detailed structure and proportions of the whale (Clarke, 1978a) and some physical properties of spermaceti oil (Clarke, 1978b) have already been published.

In Torbay, Nemertesia antennina (L.) hosts more than 150 epizoic species, most of which do not occur on other substrata in the area (Hughes, 1975). Five species, the amphipods Ericthonius brasiliensis (Dana), Pseudoprotella phasma (Montagu) and Corophium sextoni Crawford, and the gastropods Cingula semistriata (Montagu) and Cingula semicostata (Montagu), constitute 68 % of the free-living epizoites and are sufficiently abundant throughout the year to allow a study of their life-histories.

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.

The survivorship of marine invertebrates that have a life span of less than 2 years is usually assessed by observing the decrease in abundance of animals from samples taken frequently throughout the life of an identifiable cohort or generation (e.g. Crisp, 1971). This method is only suitable for species with approximately simultaneous recruitment so that the animals can be aged with reasonable accuracy and the mortality before the end of the recruitment period can safely be ignored. Such age-specific survivorship data can be used to calculate secondary production by revealing the number of animals that reach successive weights (= Allen curves) (Crisp, 1971).

Mussels (Mytilus edulis L.) were held under five different experimental conditions for 8 weeks during which measurements of physiological condition, and certain cytological and cytochemical observations, were made. The mussels were then induced to spawn and the numbers of eggs released, the weights of these eggs, and their biochemical composition, were determined. During the experiment new gametes were developed by mussels under all conditions, but there was also a simultaneous regression and resorption of previously formed gametes, particularly in mussels under the greatest stress from high temperature and lack of food. The degree of stress experienced by the animals was measured as the scope for growth, or the energy available for somatic growth and the production of gametes. The distribution and activity of lysosomal enzymes within the Leydig tissue of the mantle suggested that autolysis of these cells occurred, coupled to the mobilization of glycogen for gametogenesis. Mussels under stress produced fewer and smaller eggs, in smaller follicles, than mussels not under stress. The biochemical composition of the eggs (as µg of biochemical component per mg of egg) did not vary consistently with adult condition, but eggs from stressed females had less lipid and protein than eggs from normal females. It is suggested that these relationships between the physiological condition of the adult, gametogenesis, fecundity and the biochemical content of the eggs are important for understanding the impact of the environment on ecological fitness.

Little is known about the swimming of fish in which flexures of the body and caudal fin are not the main means of locomotion. Breder (1926) provides brief descriptive accounts and a useful classification of the main non-body modes of locomotion in teleosts. These are discussed in general terms by Harris (1937, 1953), Marshall (1965, pp. 31–41) and Lighthill (1969).

An acute toxicity threshold of 0·09–0·10 ppm added copper was determined for specimens of Mytilus edulis from the Menai Strait which were exposed to copper (as CuSO4) in a flowing sea-water system.

Results are presented which show that the closure response of the mussel to added copper is a three-part process. First, a sharp adduction of the shell valves is seen at a mean total copper concentration of only 0·021 ppm, then as the copper concentration rises, ‘testing’ behaviour is observed and finally the shell valves close to isolate the animal from its environment. The complete valve closure mechanism only operates at added copper concentrations of 0·2 ppm or more. The initial behavioural reaction of valve adduction at low concentration occurred at a significantly higher mean total copper concentration (0·16 ppm) in mussels which had been previously acclimated to 0·02 ppm total copper in sea water for 10 days.

The second maxilla is innervated typically by 35 motor neurones in Nectocarcinus antarcticus and about 39 in Cancer novaezelandiae. Muscles are multiply innervated. Within one species variations in the number of motor neurones innervating any muscle do occur but are not common.

The myxinoid cyclostomes, of which the hagfish Myxine glutinosa L. is one of the best known examples, are of unique biological interest as representatives of a group of jawless vertebrates which probably had their origin in the pteraspidomorph ostracoderms of the Ordovician era (Nybelin, 1973). They have been much studied by comparative anatomists and physiologists but somewhat neglected by ecologists. There is, for instance, very little critical information on their normal feeding biology. Perhaps one reason for this is that, although hagfish may be extremely abundant locally (their principal habitat requirements are stable, soft muddy sediments and a salinity in excess of 31 %, (Gustafson, 1935)), they tend to be missed by most exploratory fishing and biological sampling programmes. This is because benthic sampling techniques are often ill-adapted for the capture of large active organisms capable of swimming and burrowing and because, unless blocked by the catch, the cod-end mesh sizes of the trawls used by most British commercial fishermen would easily permit the escape of even the largest hagfish. However, the research otter trawls used by the Department of Agriculture and Fisheries for Scotland (D.A.F.S.) for surveying the North Sea stocks of the deep water pink shrimp, Pandalus borealis Krøyer, are fitted with cod-end covers of small mesh, and it is found that the catches frequently include small numbers of hagfish, presumably caught while swimming close to the bottom, or possibly when buried in the surface of the sediments. The present study is largely based on the examination of hagfish collected during the D.A.F.S. Pandalus surveys of 1975 and 1976. The remaining material was kindly provided by Dr J. B. Buchanan of the Dove Marine Laboratory at Cullercoats, Northumberland.

Larval anisakid nematodes are among the most abundant helminth parasites of commercially exploited marine fish in the North-East Atlantic. Consequently, the biology of Anisakis and Phocanema in commercially sized fish from the North-East Atlantic has been quite extensively studied in recent years (see for example Davey, 1972; Rae, 1972; Young, 1972; Platt, 1975). There is, however, little available information on the occurrence of larval anisakids in small fish or species not used for human consumption. This is an important gap in our knowledge since information on the infection of such fish will increase our understanding of the circulation of these parasites within the marine environment and the levels of infection in commercial species.