The purpose of the present study was to assess the relationship between sediment composition and biological community structure in mixed sands and gravel deposits of the eastern English Channel. Although some species are clearly associated with particular sediment types, the results confirm the lack of correspondence between community composition of the benthos and particle size distribution in unconsolidated sand and gravel deposits. The results also suggest that sample-to-sample variability commonly recorded in the species composition of macrofauna may reflect significant under-sampling by conventional grab sampling techniques. The implications of this for environmental monitoring and impact studies is discussed.

Field and experimental observations on sea anemones (Actinaria) Ammonia viridis (Forskål) and Actinia equina (L.) indicated that in both species body zinc concentrations usually ranged between 100 and 200 ug (g dry wt)1 in waters containing up to 200 μg I1 of the metal. At higher dissolved concentrations, as observed in Restronguet Creek, A. equina exhibited only slightly enhanced tissue levels. However, in the laboratory, zinc levels in Anemonia viridis increased markedly at sea-water concentrations exceeding 200 μg I”1. Studies on the uptake of 65Zn-labelled zinc showed that, when the sea-water concentration was increased from 2 to 52 μg 11, both species absorbed the metal and new equilibria appeared to be reached in about a week. At equilibrium, the concentration of zinc in Actinia equina had risen by up to 11%, and in Anemon ia viridis, by up to 28%. About one third of the difference between the amounts absorbed by the two species may be accounted for by zinc accumulated in the symbiotic algae (zooxanthellae) of A. viridis. Short-term (12 h) experiments showed that, although A. viridis absorbed a significant amount of labelled zinc when the concentration increased from 2 to 52 μg I1, uptake was not much greater when the concentration increased from 2 to 202 μg I1. It is postulated that, up to a sea-water concentration of 202 μg I1, the absorption of zinc is dependent on the amount adsorbed at the body surface: saturation of the surface at higher concentrations leads to more direct dependence on the level of dissolved zinc.

The effects of ten different water temperatures on the growth of newly released ephyrae of Aurelia labiata were explored. Ephyrae grown at 21°C showed the greatest growth, increasing in bell diameter from about 4.0 mm to 14.5 mm in 14 days and remained in good condition for the duration of the experiment. Ephyrae subjected to other temperatures grew at different rates. Ephyrae maintained at 8°C gradually decreased in size during the experiment, shrinking in bell diameter from about 4.0 mm to 3.8 mm by day 14, but remained in apparent good condition. Ephyrae reared at 22.5°C and above everted their bells, were in poor condition, and were unable to feed or swim effectively by about day ten. In this study the optimal temperature range for rearing A. labiata ephyrae was 12°C—21°C, which corresponds with the reported range for this species.

Pinnotheres pisum is a small crab with a carapace between about 2−1 and 18 mm. wide. The females are commonly found parasitic in the mussel, Mytilus edulis, though they have been recorded from other bivalves. The males are free-swimming and are comparatively rarely found in mussels. These small crabs are never abundant, and not more than one female has ever been found in a mussel.

Comparison of the methods of adhesion and locomotion of the typical members of the four classes of the Eleutherozoa reveals a similarity of the adhesive mechanism in the Asteroidea, Echinoidea and Holothuroidea in that adhesion is due in part to suction and in part to the secretion of mucus. The ophiuroid, on the other hand, has tube feet which, because of their lack of a well-defined sucker, must adhere merely by their intrinsic stickiness. The ability to make use of suction results from the possession of a sucker so fashioned that the median part of the disk may be withdrawn from the surface of contact, with the resultant production of a vacuum. The sucker of the asteroid, echinoid or holothurian tube foot is well adapted for this purpose. An essential feature of such a disk is the presence of an arborescent system of connective tissue fibres extending from the basal plate to the outer limit of the ectoderm. By means of this system, the pull initiated by contraction of the longitudinal musculature of the podium is transmitted to the ectoderm of the sucking disk, the central part of which is thereby lifted up. Where suction plays no part in adhesion, as in the Ophiuroidea, the arborescent system of fibres is lacking.

Information on Balaenoptera edeni strandings along the Brazilian south-east coast and feeding associations with other marine vertebrates are reported. A total of 19 strandings were observed from 1972 to 2003 along ≈1200 km of coast. Strandings were evenly distributed among seasons with no distinguishable peaks. Besides the stranding data, opportunistic observations on Bryde's whales engaged in feeding activities were reported from nine cruises along São Paulo and Rio de Janeiro State coasts (22–24°S). Bryde's whales were observed preying on Brazilian sardines (Sardinella brasiliensis) in at least three events, and possibly two others. Associations with other marine vertebrates were observed, and included dolphin fish (Coryphaena hippurus), little tunny (Euthynnus alletteratus), unidentified sharks, terns (Sterna hirundinacea, Sterna spp.), brown boobies (Sula leucogaster), frigate birds (Fregata magnificens), parasitic jaeger (Stercorarius cf. parasiticus), albatrosses (Thalassarche spp.), and bottlenose dolphins (Tursiops truncatus). Stranding data and on-board observations support the hypothesis that Bryde's whales are common in coastal waters of south-eastern Brazil.

The marine rotifer Brachionus plicatilis Müller was grown bacteria-free in a chemostat with the alga Brachiomonas submarina, labelled with Co vitamin B 12, as the limiting nutrient.

Records of parasitic worms from British marine fishes are still rather scanty. A good deal of attention has been paid to the subject of the Trernatodes by Nicoll, whose valuable list (1915) is indispensable to anyone working in this field. Nicoll is himself responsible for the records of the majority of the 49 species of Trematodes given in the second edition (1931) of the “Plymouth Marine Fauna.” The only work done on the Cestodes of fishes at Plymouth appears to have been that of Woodland (1927, a and b), as a result of which 14 species have been placed on record. Very few data are available as to the Nematodes, and none as to the Acanthocephala, of the Plymouth fauna.

Sampling cruises were carried out on three coastal stations of the northern Ionian Sea over one year to investigate the effects of environmental factors on phytoplankton and picophytoplankton composition and succession. Larger phytoplankton (micro and nano fractions) was determined by using the Utermöhl settling technique, while picophytoplankton fraction was determined by epifluorescence microscopy. Furthermore, microbiological procedures were applied to investigate cyanobacterial diversity in the studied area. Results suggested that the most striking feature of phytoplankton communities was the high spatial variability in terms of abundance and biomass, which showed specific coastal Mediterranean values. Undetermined phytoflagellates and diatoms were the dominant groups of the Utermöhl fraction of phytoplankton, while round to rod-shaped small sized cyanobacteria represented the picophytoplankton fraction. Our data suggested that in the northern Ionian Sea the phytoplankton development was related to phosphorus availability and to ‘nitrogen-rich’ waters. Also the picophytoplankton seasonal trend was significantly correlated to N-compounds as well as to water temperature.

In addition to the typical picoplanktonic Synechococcus, the culture techniques allowed us to isolate and identify cyanobacteria belonging to the pleurocapsalean genus Stanieria and the oscillatoriacean genera Geitlerinema, Leiblenia, Leptolyngbya, Oscillatoria, Pseudanabaena and Spirulina. These species represent a minor fraction of the total cyanobacterial community in terms of biomass, but their importance is related to their contribution to the phytoplankton diversity.

The blue shark is a pelagic species having a virtually circumglobal distribution in tropical and temperate seas. In the northern hemisphere, during the warmer months, they extend their range northwards in both the Pacific and Atlantic (Strasburg, 1959; Bigelow & Schroeder, 1948; Templeman, 1963). Between May and October they occur regularly and in considerable numbers around the south-west peninsula of England. Strasburg showed that in the central Pacific blue sharks are opportunistic feeders as were the other pelagic species he studied, their diet consisting mainly of squid and small fish. Bigelow & Schroeder suppose herring (Clupea harengus L.), mackerel ((Scomber scombrus L.), sardines (Sardina pilchardus Walbaum) and a variety of cephalopods to be the chief diet in northern waters, together with Squalus acanthias L. and various bottom fish on the fishing banks. In warmer waters anchovies (Engraulis encrasicolus L.), flying fish and the occasional sea bird caught resting on the water are known to occur in their diet. Bigelow & Schroeder also quote the well-known stories of blue shark following boats for offal and feeding on the carcasses of harpooned whales. Le Brasseur (1964) examined the diet of blue sharks caught by gill net in the Gulf of Alaska and in general confirmed Strasburg's observations. However, he stated that when salmon (Oncorhynchus sp.) were available in gill nets blue shark might selectively feed on them, while by-passing other readily available species occurring in their normal diet. Couch (1862) examined the stomachs of two specimens from Cornish waters, finding herring, mackerel and garfish (Belone belone L.), as well as Squalus and Conger conger L. Lo Bianco (1909) found anchovies and cephalopods in one of two specimens caught in the Bay of Naples, the other of which contained large numbers of flying-fish eggs (Exocoetus sp.).

Inactive Mn concentrations have been measured in lobster tissues. In the internal tissues of fresh animals, muscle contains 0.5–1.1 μg/g wet tissue, hepatopancreas contains 4.1–5.7 μg/g, excretory organs contain 2–5.5 μg/g and the blood contains 1.4–3.8 μg/g. Gill Mn concentrations are very variable and up to 30 μg/g are found. About 98 % of the Mn in the body lies in the calcified exoskeleton. Concentrations in the carapace are variable and are of the order of 100–300 μg/g of wet tissue. Possible ways in which the body Mn content may be controlled have been studied.

Manganese is lost from the blood during starvation and is absorbed so slowly from solution in sea water that normally an appreciable amount of the body Mn must be absorbed from food. Absorption from the stomach takes place via the hepatopancreas and the amount absorbed appears to be proportional to the Mn concentration of the stomach fluid. Similarly, there is no evidence that the slow absorption of Mn from solution in sea water across the gills can in any way be controlled and it may be a passive rather than an active process.

1. The vertical distribution of many species in daylight in the Plymouth area is shown, as a result of the examination of a number of serial hauls taken with the stramin ring-trawl between the dates April 2nd and August 6th, 1926.

2. It is shown that probably the errors introduced by the employment of a non-closing net are for the present purpose negligible.

3. The indications are that most species have an optimum level at which they live, in the daytime, the actual depth varying from day to day according to weather and other conditions.

4. A few species appear to show no preference, being present equally abundantly at all depths or showing marked changes in the region of greatest abundance from day to day.

5. A provisional list is given on page 567, showing the order in which many of the different species appear in greatest abundance from the surface downwards.

6. The vertical distribution appears to differ for the two sexes of Calanus finmarchicus, the males tending to avoid the surface layers more than the females.

7. The presence of the medusa Cosmetira pilosella in fair numbers in a catch in the daytime in the Plymouth region would seem to be a reliable indication that the net has been fishing below 20 metres.

8. A catch of Calanus finmarchicus made by the stramin ring-trawl consists nearly always of over 80 per cent adults.

9. No attempt has been made definitely to correlate behaviour with external factors: more observations are to be desired.

10. Brief notes are given on the seasonal distribution of various species. The danger of drawing conclusions about seasonal abundance from daylight hauls only is shown by the results for Tomopteris helgolandica (p. 575).

The perivisceral and ambulacral fluids of Asterias rubens have been shown to be not only isosmotic but isoionic with sea water, even if that medium is diluted by nearly half. However, there is a slight accumulation and regulation of calcium in the perivisceral fluid and to a much more marked extent, potassium in the water vascular system. The rapidity with which the potassium diffuses away when the ambulacral fluid is dialysed against sea water suggests that its presence in the water vascular system is due to an active accumulatory mechanism. This mechanism is capable of functioning when the animal encounters sea water of significantly reduced salinity, over the temperature range 0—20° C and extends throughout the season apparently uninfluenced by the breeding cycle or sex of the animal. Smaller animals tend to have a higher concentration of potassium in the water vascular system than do larger ones. Direct and indirect measurements of salt loss under various conditions, together with observations on the rate of lithium transfer, suggests that the integument is very permeable to many ions as well as to water. This supports the hypothesis that the ionic regulation observed results from an active process and not merely from an impermeability of the integument, although measurements with potassium itself have not yet been made.

Cetacean sightings are reported from opportunistic deployment of observers on fishing boats during 1998–1999 in Galician waters (north-west Spain), a region of high biodiversity, intensive fishing activity and an important cetacean habitat. During 111 trips, a total track length of 8128 km and estimated area of approximately 9840 km2 was surveyed, including both inshore and offshore waters.  The most frequently sighted species were common dolphins (Delphinus delphis) and bottlenose dolphins (Tursiops truncatus). Taking account of biases in the survey data, the former species was most commonly sighted in deeper offshore waters (>200 m depth) with the highest sightings rate in the second quarter of the year. Bottlenose dolphins were seen mainly in inshore waters to the south of Galicia but also in offshore waters further north. Sightings rates were higher when the observers' boats were engaged in fishing than when travelling. Published dietary data suggest that this may simply indicate that dolphins tend to congregate in fishing areas where their main prey occur.  Several different treatments of the data were used to derive relative abundance indices (taking account of observation biases and of spatial variation in survey coverage). These calculations suggest that there may be around 7000–10,000 common dolphins and 600–1000 bottlenose dolphins in Galician waters, although dedicated surveys are needed to produce robust estimates.  Other species seen during surveys included the long-finned pilot whale (Globicephala melas), harbour porpoise (Phocoena phocoena), Risso's dolphin (Grampus griseus) and fin whale (Balaenoptera physalus). Incidental observations from boats and land-based surveys supported the high relative abundance of common dolphins and, in inshore waters, of bottlenose dolphins, as well as providing additional records of porpoises and Risso's dolphins.

The growth of littoral and sublittoral barnacles has been studied in some detail using linear, surface or volumetric measurements (see Barnes & Barnes, 1959). The growth curve in terms of linear dimension generally included an extended straight section which implies, assuming a constant shape, that the volume is increasing with time in proportion to the area (Crisp, 1960). Hence a plot of basal diameter against time is the simplest characteristic of the growth during most of the life of an isolated specimen. In most studies the shells are measured at daily, weekly or monthly intervals and the effect of different factors on growth evaluated. Thus, it has been claimed experimentally that many factors influence directly the growth of barnacles. These factors and their effects are outlined in Table 1.

Using 14C as a tracer in experiments of 2–3 h duration it has been demonstrated, both with individual species in culture and natural populations, that marine phytoplankton from tropical inshore waters releases products of photosynthesis insoluble extracellular form. The relative extent of this excretion varied between 1% and 20% of the total carbon fixed but on any particular occasion the amount of extracellular products was approximately proportional to the amount ofphotosynthesis which had taken place. An inverse relation-ship between relative extent of excretion and phytoplankton abundance as measured by chlorophyllα concentration was found, in agreement with the results of previous workers. The relative extent of excretion did not appear to be greatly different in brackish water of 12–3% salinity from that in ordinary sea water.

Submarine caves with sulphurous springs at Cape Palinuro, Campania, Italy, have a richer fauna than expected from the known oligotrophic nature of the cave habitat. Warm water containing sulphide issues from springs and rises above the cooler ambient sea-water with a sharp thermocline/chemocline between. The warm water then escapes from the caves mixed with cooler sea-water, probably inducing an inflow of ambient sea-water. Bacterial mats, often dominated by large species of attached bacteria resembling Beggiatoa, line the upper parts of the inner caves and act as primary producers, fixing CO2 by means of the autotrophic enzyme ribulosebisphosphate carboxylase. Many of the animals in the innermost parts of the caves live close to the chemocline or just below, where they would experience fall-out of bacterial organic matter, and some carry filamentous bacteria on their tubes and hard parts. Dominant members of the community include sponges, cnidarians, and tubicolous polychaetes.

Although much investigation has been made on the food of adult fish the information as to the food of the very young is scattered and fragmentary. It is the purpose of this paper to report on the food of a number of post-larval fish which have been examined fresh from the tow-nettings through the year 1917 from Plymouth Sound within the Breakwater and outside as far as the region of the Panther and Knap Buoys (about 2 miles from the shore) and occasionally from Cawsand Bay. The food of a number of preserved post-larval fish has also been investigated which were taken in the Young Fish Trawl in 1914 and reported on by Dr. Allen (1917).

Field surveys were conducted in order to collect information on the occurrence of wild Artemia populations in hypersaline environments such as salt lakes, lagoons and salty rivers. The mating behaviour of Artemia populations and the presence or absence of males were carefully recorded. Sampling involved the use of plankton nets. Collected cysts were characterized on the basis of their diameter and chorion thickness, while nauplii (instar-I) were characterized on the basis of their total length. Artemia populations were found at 17 different geographical locations scattered over 12 Iranian provinces. All Iranian Artemia populations are parthenogenetic with the exception of Artemia urmiana from Urmia Lake. During the last five years severe salinity increase has caused a dramatic reduction of population sizes in several hypersaline settings in Iran. The study of cyst and naupliar biometry revealed substantial differences between populations and can be used, to some extent, for their discrimination. Cyst diameter mean values range from 243.2 to 285.4 μm. For some Iranian parthenogens, cyst diameters were among the smallest recorded so far for parthenogenetic Artemia. The total length of newly hatched nauplii ranges from 455.5 to 529.8 μm.

A method is described for obtaining growths of phytoplankton in samples of crude sea water, similar in composition but several hundred times more dense than phytoplankton communities occurring in the sea.

The ratio of nitrogen to phosphorus utilized by such communities has been determined.

They use ammonium in preference to nitrate, although the latter may be many times more concentrated than the former.

They use urea and uric acid as sources of nitrogen.

Certain amino-acids when added as sources of nitrogen were attacked by the bacteria in the community and either the ammonium set free or both the ammonium and the amino-acid were used by the phytoplankton. Others, as d-leucine, were not utilized, or, as l-leucine, only slowly utilized.

Sodium nucleinate and caseinate were rapidly broken down when added to crude sea water by bacterial action, and the phosphate produced utilized by phytoplankton. There was no significant utilization of glycerophosphate.