Relationships between wet body weight, dry body weight and ash-free dry body weight (AFDW) were established for the aspidochirote sea cucumber Holothuria forskali (Echinodermata: Holothuroidea); a wetdry weight ratio of 6–38:1 was found. Length-weight relations were also determined. Low oxygen tensions and mechanical trauma induced H. forskali to eviscerate (70% of individuals tested). Respiratory measurements of intact and eviscerated sea cucumbers were determined at 17°C. For intact animals, oxygen consumption (ul h1) was directly related to AFDW (the slope of the regression line, b=0–60), whereas weight-specific oxygen consumption (Vo2; ul g1AFDW h) was inversely related to AFDW (b=0–54). Oxygen consumption of eviscerated sea cucumbers was independent of AFDW (b=0-\5), but Vo 2 was inversely related to AFDW (t–0–85). There were no significant differences between the respiratory rates of intact and eviscerated individuals, indicating that H. forskali is not so dependent upon respiratory trees for oxygen uptake as previously assumed.

A key to all nine described marine species of naked lobose amoebae classified in the genus Vannella Bovee, 1965, is presented. All six species studied with the electron microscope have the characteristic surface structure found also in freshwater members of the genus. The key includes five species isolated from British waters, including three new species; a fourth new species is from the Persian Gulf area. Generic identification of Vannella, even in mixed material, can be made readily with the electron microscope, which is sometimes necessary for positive distinction from Platyamoeba. Further identification to species is a light-microscopical procedure. Members of this genus are cultured on bacteria, which are probably their main food in nature.

In a recent study (Ross, 1957) isolated marginal sphincter preparations of the sea anemone, Calliactis parasitica, showed two distinct responses to stimulation: (1) a quick contraction in response to stimuli at frequencies from 0–2 to 3–0 sec, the facilitated response of Pantin (1935 a) beginning only on the second stimulus of a series, with a latent period of about 0 1 sec; (2) a smooth slow contraction in response to stimuli at lower frequencies, with a latent period of not less than 30 sec, and beginning only after several stimuli. This slow movement of the marginal region had not been detected in work on whole animals, but it is similar to the contractions of the ‘slow’ muscles of Calliactis (Pantin, 1935 b) and Metridium (Batham & Pantin, 1950 a). However, Calliactis sphincter shows almost no spontaneous activity.

Both quick and slow contractions had previously been observed in excised sphincters and mesenteric retractors of Metridium (Batham & Pantin, 1954), the chief muscles utilized in the closure of that animal. In all these cases, the quick contraction would seem to be a specialized mechanism for sudden withdrawal superimposed upon, and perhaps developed from, a more primitive and general slow contractile mechanism. As part of a programme to investigate and compare the properties of quick and slow contractions in these muscles it seemed desirable to see what part, if any, slow contractions of the marginal sphincter play in the life of Calliactis. This involved us in a wider study of the neuromuscular activity of this anemone which normally lives on shells inhabited by the hermit crab, Eupagurus bernhardus.

The Pycnogonida are a group regularly recorded in deep-sea benthic samples, although normally in low numbers. Most analyses from such surveys record new species, and many of these remain known only from a few specimens, often only the types. However, the amount of deep sea-bed sampled is necessarily proportionately so small that it may be argued that any species taken are probably common, owing to their having been sampled at all. It is evident from the gaps in the (often world-wide) distribution of these known species and their limited occurrence that deeper water pycnogonid faunas are still at best poorly known (q.v. Child, 1982).

Cochlodesma praetenue is well adapted for a sedentary life in sheltered conditions in soft substrata at low-water mark to a depth of 60 fathoms.

The habits, morphology and ciliary feeding and cleansing mechanisms are described and compared with those of members of the related families Thraciidae, Pandoridae and Lyonsiidae.

The complex ligament is described. The mantle edges are extensively fused. The detailed structure of the siphons is described and related to their function of laying down mucus-lined inhalant and exhalant tubes.

The morphology and ciliary currents of the stomach show modifications similar to those previously described for Pandora. These modifications involve the extent of the major typhlosole and the replacement of an intestinal groove by lateral rejection grooves.

Analysis of three large samples shows that Cochlodesma from the Northumberland coast live for a maximum of 5 years. These animals become mature in their third year, spawning in early November.

The embryonic and larval development of the pipefish Nerophis lumbriciformis is described. The full development sequence lasted 30 d (at 14–15°C), being shortened to 25–26 d at higher temperatures (16–17°C), and hatching occurred throughout a 2–3 d period. Unlike species of the genus Syngnathus, the newly hatched larvae presented a functional mouth apparatus and the yolk sac completely absorbed.

The annual commercial catch from the Southern Zone of the South Australian rock lobster (Jasus edwardsii) fishery is ~1900 tonnes, representing ~50% of total landings from south-east Australia. A single minimum legal size (MLS) of 98.5 mm carapace length (CL) exists across the entire zone. Fecundity (F), size at onset of maturity (SOM) and relative reproductive potential (RRP) of female rock lobsters were investigated in two major fishing regions, i.e. the North Southern Zone (NSZ) and South Southern Zone (SSZ) with a view to providing a basis for future fine-scale spatial management of the resource. F ranged from 45,292 to 466,800 eggs per female and increased proportionally with CL according to the relationship: F = 0.0584 × CL3.1642. F was significantly higher in the NSZ compared to the SSZ but was attributed to differences in lobster size between regions. There was no significant difference in the number of eggs · g−1 of egg mass between areas. SOM, estimated as the size at which 50% of females reached sexual maturity (L50) was higher in the NSZ (104.1 mm CL) compared to SSZ (92.3 mm CL). Approximately 20% of lobsters above the MLS in the commercial catch in the NSZ were under the L50 estimate. RRP, as a measure of egg production, was calculated for each size-class from the product of F, SOM and population length–frequency. The modal RRP size-classes in the NSZ were 117.5–122.5 mm CL, while in the SSZ it was 97.5–102.5 mm CL. Only 6% of RRP was contributed by female rock lobsters below the MLS in the NSZ, compared to 34% in the SSZ. Regional differences in SOM and RRP in the Southern Zone of South Australia suggest that different MLSs may be beneficial, particularly if the fishery is to be effectively managed at finer spatial scales.

Three species of medusae of the genus Podocoryne M. Sars have been collected in the Clyde Sea Area: P. hartlaubi Neppi & Stiasny, P. borealis (Mayer) and P. camea M. Sars. Their hydroids have also been found there, and medusae liberated in the laboratory have been reared to maturity. Detailed illustrated accounts of the hydroids and of the developmental stages of the medusae are given.

The hydroid of P. hartlaubi proves to be identical with the hydroid Podocoryne areolata (Alder), a species long known to liberate medusae, which however have not previously been referred with certainty to any known species of medusa. By priority the name P. areolata has seniority over P. hartlaubi and applies to both hydroid and medusa. The hydroid P. hartlaubi reported from Naples by Yamada is discussed, and is considered to be identical with P. areolata. In the Clyde Sea Area the hydroid has been found only on certain small gastropod shells occupied by hermit-crabs.

The hydroid of P. borealis has hitherto been very inadequately known. The hydroid is very common in the Clyde Sea Area, living on a variety of host animals on muddy grounds. Colonies have also been reared in the laboratory from ripe medusae caught in the sea. Abundant material has accordingly been obtained, making possible a full description of the species.

Recently I have reported experiments which have led me to throw doubt on the universal applicability of the theory of the production of a moult-inhibiting hormone by the eyestalks of the decapod Crustacea (Carlisle, 1953). I suggested that the eyestalk moult-inhibiting hormone might be associated with the existence of a definite moulting season. In animals which possessed such a moulting season moultingwould then be inhibited outside this season, but within the season there might well be no such inhibition. The experiments reported here support a modified form of this hypothesis.

Mud volcanoes are singular seafloor structures classified as ‘sensitive habitats’. Here we report on the sponge fauna from a field of eight mud volcanoes located in the Spanish margin of the northern Gulf of Cadiz (North-eastern Atlantic), at depths ranging from 380 to 1146 m. Thirty-eight beam-trawl samplings were conducted (covering over 61,000 m2) from 2010 to 2012, in the frame of a EC-LIFE + INDEMARES grant. A total of 1659 specimens were retrieved, belonging to 82 species, from which 79 were in the Class Demospongiae and three in Hexactinellida. Two species were new to science (Jaspis sinuoxea sp. nov.; Myrmekioderma indemaresi sp. nov.) and three others recorded for the first time in the Atlantic Ocean (Geodia anceps, Coelosphaera cryosi and Petrosia raphida). Five additional species were ‘Atlantic oddities’, since this study provides their second record in the Atlantic Ocean (Lanuginella cf. pupa, Geodia cf. spherastrella, Cladocroce spathiformis, Cladocroce fibrosa and Haliclona pedunculata). Basic numerical analyses indicated a significant linear relationship between the species richness per m2 and the number of sponge individuals per m2, meaning that in most volcanoes many species occur in equivalent, moderate abundance. Likewise, sponge species richness increased with depth, while the abundance of hard substrata resulting from carbonate precipitation and the fishing activities around the volcanoes had no detectable effect on the sponge fauna. However, in the latter case, a negative trend – lacking statistical support – underlaid the analyses, suggesting that a more extensive sampling would be necessary to derive more definitive conclusions in this regard.

A method of demonstrating cellulose utilization in biological systems by measurement of the turbidity of a cellulose suspension in a photo-electric absorptiometer is described. The crystalline styles of Ostrea edulis and Mytilus edulis appear to contain a cellulolytic factor as yet uncharacterized.

Six species of rotifer, including one oceanic species and representing four genera, are recorded for the first time from Plymouth. Remarks are made on various interesting features of their anatomy, details are given of their times of occurrence at Plymouth, with notes on their location and known distribution in other parts of the British Isles, and in foreign waters.

Attention is called to the apparent poverty of the Plymouth marine and brackish-water Rotifera as compared with that of Liverpool, investigated at length by Galliford. It is stressed that no exact conclusions as to the reason for this can be made until after a more exhaustive survey, as some likely habitats adjacent to the Sound were not investigated. Attention is also called to the caution which must be exercised in terming rotifers marine, as most of those collected in coastal waters appear at present to be confined to areas where a considerable amount of fresh water is discharged into the sea. At least two species, one of which occurs in the Sound in May, are known to be truly oceanic, having been found in mid-Atlantic.

It is suggested that ‘brackish’ and ‘estuarine’ are the terms most applicable to the majority of coastal rotifers in the present state of our knowledge.

The annual pattern of burial depth in natural populations of the infaunal bivalves Tagelus dombeii (Tellinacea) and Venus antiqua (Veneracea) is described in relation to annual food availability in both the water column and the sediment and abiotic factors (temperature and salinity) at Coihuín tidal flat, in southern Chile. A field experiment in which burial depth was measured in situ each month (over 14 months), with the aid of a fixed-length nylon thread attached to the shell. For T. dombeii the results showed a significant increase in burial depth with increasing bivalve size and syphon weight. Tagelus dombeii had a mean burial depth of 17·5 cm, which was three times more than in V. antiqua (5·30 cm). The burial depth dynamics for both species displayed a strong correlation with food availability in the water column. Approximately 60% of the variability in burial depth in T. dombeii and V. antiqua was explained by concentration of chlorophyll-a in the water column. Food concentration on the sediment surface did not effect burial depth, i.e. deposit feeding seems to be of minor significance in either species.

The stomach contents of 1096 specimens of Chelidonichthys lucerna were examined in order to analyse their diet composition according to fish size, sex, depth and season. Sampling was carried out from May 2005 to March 2007 during several bottom trawl surveys in the Adriatic Sea (north-east Mediterranean). Feeding activity was more intense in juveniles than in adults. The most important prey was Crustacea (mainly Decapoda: Brachyura, such as Goneplax rhomboides, Liocarcinus spp., Philocheras spp.) and Teleostei (mainly European anchovy Engraulis encrasicolus and black goby Gobius niger). There was no difference between male and female diet. Feeding habits varied with size, with fish dominating the stomach contents of larger specimens. Finally, fish increased in winter and crustaceans in summer. Chelidonichthys lucerna shows a generalist and opportunistic foraging behaviour, preying mainly epibenthic and nectobenthic organisms.

Population density, biomass, seasonal growth and gonad index of the heart urchin Echinocardium cordatum were monitored in muddy sediments of the Seto Inland Sea, Japan, from July 1998 to July 2000. Rates of sediment ingestion by the urchin were also measured. Juveniles settled in winter and their growth in the first year was rapid. Individual somatic mass in terms of ash-free dry weight (AFDW) increased from about 0·1 to 40 mg while the test length increased from about 2 to 20 mm. At the end of the second and third year (early December), somatic mass averaged 90 and 120 mg AFDW (test length=30 and 33 mm), respectively. The gonads of both year-classes matured during this period and spawning followed within two months. Individual E. cordatum (test length=29–34 mm) ingested sediments at rates of 14–43 mg wet weight per hour. Population density (28 m−2) and AFDW biomass (2·8 g m−2) of E. cordatum (test length [ges ]15 mm) were high at the start of monitoring (July 1998), remained relatively constant through the next spring and rapidly decreased to <2 m−2 and <0·2 g AFDW m−2, respectively, by December 1999. When abundant, E. cordatum comprised about 60% of the macrobenthic biomass in the study area and its annual production in AFDW reached about 1·5 g m−2 y−1, suggesting substantial contributions of the urchin in material cycling through the sediments.

The solitary ascidian Styela clava is recorded for the first time in Portuguese waters. It was found at three sites on the west coast of Portugal. This represents the southern limit of its recorded distribution in European waters. The Portuguese specimens are described and compared with UK specimens.

‘During the month of July 1900 the Lord Commissioners of the Admiralty consented, at the request of the Council of the Royal Society, to place H.M.S. “Research” at my disposal for an investigation of the plankton of the Bay of Biscay’ (Fowler, 1904). The area of study was 78 x 20 nautical miles and bounded by the latitudes 46° 43' N and 47° 29' N and longitudes 7° 15' W and 8° 18' W. Fowler (1909) subsequently worked up the halocyprid Ostracoda from tow-net samples taken either with a 20 in (45 cm) diameter net with either 45 or 60 mesh (i.e. pore apertures of about 0.50 or 0.35 mm), or a mesoplankton-net that could be opened and closed. The nets were lowered to depth and left dangling while the ship drifted. This was the first attempt to study the vertical distribution of halocyprid ostracods, and the only study considering this planktonic group in the Bay of Biscay for another 74 years, apart from Colman (1962), who identified the contents of his plankton samples only to Order. Fowler's results were dogged by his taxonomic misconceptions (Skogsberg, 1920). He believed that many of the larger species were later moult stages of smaller ones, e.g. he synonymized C. macrocheira Müller with C. magna Claus. Fortunately he illustrated most of the forms he was dealing with and it has been possible to re-ascribe them with reasonable confidence.

Two reciprocally monophyletic mitochondrial clades of the commercially valuable jellyfish Catostylus mosaicus are endemic to south-eastern Australia. Here, medusae in the two clades are shown to differ also in colour and in the dimensions of their papillae, oral disk, and bell depth. They are referred to two varieties recognized in 1884 by von Lendenfeld. The clade occupying localities adjacent to Bass Strait is redescribed as subspecies C. mosaicus conservativus; the clade from New South Wales and southern Queensland spans the type locality (Port Jackson) of C. mosaicus and is designated C. mosaicus mosaicus. Their ecology and colour, in the context of von Lendenfeld's original descriptions, and the implications for fisheries are discussed.

The white-beaked dolphin Lagenorhynchus albirostris is the most numerous cetacean after the harbour porpoise Phocoena phocoena in the North Sea, including Dutch coastal waters. In this study, the diet of 45 white-beaked dolphins stranded on the Dutch coast between 1968 and 2005 was determined by analysis of stomach contents. Although 25 fish species were identified, the diet was dominated by Gadidae (98.0% by weight, 40.0% in numbers), found in all stomachs. All other prey species combined contributed little to the diet by weight (2.0%W). The two most important prey species were whiting Merlangius merlangus (91.1% frequency of occurrence (FO), 30.5%N, 37.6%W) and cod Gadus morhua (73.3%FO, 7.4%N, 55.9%W). In numbers, gobies were most common (54.6%N), but contributed little to the diet by weight (0.6%W). Three stomachs contained different prey compared to the others: one animal had taken 2250 gobies, accounting for 96.4% of all gobies found; one animal had fed on 29 small sepiolids; and one animal had solely taken haddock Melanogrammus aeglefinus. Squid and haddock were not found in any other stomach. The overall diet showed a lasting predominance of whiting and cod, without clear changes over time (35 years) or differences between sexes or size-classes of dolphins. This study adds to earlier published and unpublished data for Dutch coastal waters and agrees well with studies of white-beaked dolphins from other parts of the species’ range, in the North Sea and in Canadian waters, with Gadidae dominating the diet on both sides of the Atlantic.

Marine reserves and restocking initiatives are sometimes used as a tool to enhance spiny lobster stocks. In such initiatives it is crucial to follow the movement of lobsters once they are released at sea in restocking experiments.

This paper presents the results of the application of an ultrasonic telemetry system to the monitoring of 11 lobsters (90±14 mm mean carapace length) released in the Capo Gallo-Isola delle Femmine Marine Reserve in north-western Sicily, central Mediterranean. The system comprised transmitters glued onto the lobster carapace, and manual as well as automated receivers to locate tagged animals. The data (i.e. number of detected signals) were tested to assess any difference in the diel activity of lobsters. The field study lasted 79 days in total. Lobsters remained in the study area for periods ranging from a few hours to the entire duration of the study. The longest distance travelled by a tagged lobster was 2.2 km. The number of signals varied significantly across the day, with the highest value recorded in the full-light hours (1000–1500), but they were not sufficient to assess clearly the diel activity of the released lobsters.

The interpretation of data suggests that: (1) released lobsters preferred a deeper habitat than that of the release site; and (2) the lobsters that reached a rough rocky area with available shelters settled there, while those that did not meet such a habitat soon moved out of hydrophone detecting range.