Several methods have been devised for sampling plankton in the different water layers in the ocean, but for many years vertically hauled nets closed by a method devised by Nansen (1915) have fulfilled this purpose. Recently, however, an investigation by Barnes (1949) cast doubt on the validity of this method for quantitative work, and as in his paper he specifically referred to nets of the type used on the ‘Discovery’ Expeditions, the present observations were conducted to determine whether Barnes's findings were of general application to the method.

A new species of the hermit crab genus Pagurus (Crustacea: Anomura: Paguridae) is described from Brazil. This is the first new species described in 30 years, with morphological characteristics of the exilis group.

Galathea intermedia is common, but cryptic, on Clyde maerl deposits where it lives in small groups of mixed sex and age, sharing shelters (typically dead Dosinia shells) to avoid predation. Its appearance is marked by six iridescent blue spots which may play an important role in intra- or interspecific interactions.

Laboratory experiments were carried out upon Elphidium crispum to determine the mechanism by which this species remains epifaunal, by investigating geotaxism, phototaxism, temporal influence and responses through ontogeny. Different size-classes of specimens were tested for phototaxism and geotaxism, over four and five months respectively. Specimens of the smallest size-class tested (250–355 μm) were significantly phototaxic and geotaxic. Significant positive phototaxism was demonstrated in all tests except one, with specimens in the size-class 500–1000 μm giving particularly significant results for the months of June and July 1994. Specimens were significantly geotactic for three of thirteen tests: both negative and positive geotaxism were demonstrated.

An investigation on inheritance in hybrids between the three English species of Echinus was carried out in the Marine Biological Laboratory, Plymouth, during 1909–1912 by C. Shearer, W. de Morgan, and H. M. Fuchs. In a paper published in the Phil. Trans. Royal Soo., Ser. B, Vol. CCIV., p. 255, the results of this work were described in detail. At the time of publication, E. miliaris had been raised from the egg to maturity in the laboratory, in the course of one year, and a second generation had been obtained from these individuals, but none of the hybrid urchins had as yet reached maturity. This year, however, some of the hybrids have become sexually mature, and from them a second hybrid generation has been raised.

The urchins which have formed ripe genital products are four individuals of the cross E. esculentus X E. acutus (referred to below as EA) derived from fertilizations made in 1912. The largest of these urchins now measures 6 cm. in diameter, exclusive of the spines. On May 11th, 1914, two of these hybrids laid eggs in the tank in which they were kept. Naturally these eggs could not be used for experimental purposes, since they were deposited in the sea water of the aquarium circulation, and therefore not under sterile conditions. On June 6th I induced three of the four to deposit genital products without cutting them open, under conditions which excluded the possible presence of foreign eggs or spermatozoa. It is hardly necessary to mention here that, as in all the previous work on Echinus hybrids, the fact of the complete absence of such sperm was made certain by controls of unfertilized eggs, none of which segmented.

Although locally caught drift herrings may be landed at Plymouth from the end of September onwards until the beginning of March, the fishery only assumes economic importance during the months of December and January, when a large number of visiting drifters from both Cornwall and East Anglia are making daily fishing trips, using Plymouth as their temporary base.

Earlier studies on the problems of the Adriatic Sea and the knowledge of its hydromedusae are restricted to the northern part. Will (1844) mentioned six species of hydromedusae found in the Bay of Trieste. Several studies ensued from the northern part of this sea, until Neppi (1912, 1915, 1922), Pell (1911, 1938), Kramp (1924), Babnik (1948) and Benović (1971 a) included other areas. Some specimens from the middle and southern Adriatic are mentioned in the planktonic works of Gamulin (1948, 1976), Hure (1955, 1961), Buljan, Hure & Pucher-Petković (1973) and Vučetić (1957, 1961, 1966).

Rees (1949) has established significant biological differences between the two forms of the copepod Calanus finmarchicus, namely finmarchicus and helgolandicus. It is therefore necessary that in future research on the behaviour of Calanus the two forms should be distinguished.

I have myself published observations on the vertical distribution of Calanus and on the seasonal changes in size of individuals of the populations of this copepod off Plymouth. In order to know whether my results have been vitiated by the presence of the two forms in the collections, I have re-examined representative samples of adult females, using the fifth leg as the distinguishing character. The collections in question were those made in 1926 which formed the subject of a paper on seasonal changes in vertical distribution and in the sizes of individuals of different generations (Russell, 1928); and those made in 1931 and recorded in my paper on the vertical distribution of Calanus in relation to light intensity (Russell, 1934).

Sagartiogeton laceratus Carlgren. was observed in 1979 in large numbers (11–20 m) in shallow water (5 m below chart datum Sullom Voe) at Whaal Firth, Yell, Shetland, at a site named Stany Pund. It was recorded at a nearby site, Poita, at a lower density (1–2 m) in deeper water (6–8 m below CD.), and was also recorded as ‘common’ at the shallow head of the firth.

Very large numbers of Aurelia aurita (L.) were observed within the sheltered, shallow arm of the firth, within the upper few metres of water.

Each year since 1979 the same occurrence has been noted, and in the summer of 1980 the predation of Sagartiogeton upon Aurelia was observed and photographed on several occasions. These observations were repeated in 1982.

Sagartiogeton laceratus is found attached to shell fragments in silt, the column inclined towards the current. During ingestion the tentacles shorten, and the mouth, disc, and column, distend many times their normal dimensions. (Estimated to be 400% for the column, disc.)

It seems likely that the occurrence of both species in sufficiently large numbers to make predation noteworthy is due to the position and depth of Whaal Firth. It forms a north facing ‘trap’ on the eastern side of Yell sound through which ebb and flood tides move rapidly. The total length of Whaal Firth is approximately 7 km of which 4 km are relatively exposed, and 3 km sheltered.

This study investigated the diet of longnose stingray Hypanus guttatus in the tropical waters of north-eastern Brazil. Samples were obtained from monthly sampling of artisanal fisheries from August 2007 to July 2008. A total of 258 specimens were examined, 127 females and 131 males, and stomach contents analysis suggested H. guttatus to be a generalist and opportunistic predator feeding on the most available prey in the environment. There was no significant difference in the diet composition of males and females, or between seasons. However, an ontogenetic dietary shift was observed with larger individuals having an increased proportion of molluscs in the diet, whilst smaller individuals predated primarily on small crustaceans.

Members of the genus Phascolion Théel are probably the most familiar of sipunculans because most species inhabit the empty shells of molluscs and other similar structures and are therefore easily collected in dredge samples. Although the genus is represented in most seas and depths, few species have been investigated in detail and much of our knowledge is based on studies of the widespread Atlantic species P. strombi (see Åkesson, 1958; Hylleberg, 1975; Kristensen, 1970; Wesenberg-Lund, 1929). P. strombi is known to be remarkably plastic in many of its characters, particularly external, to the extent that Gerould (1913) was able to distinguish seven varieties in the western Atlantic region alone. Much of the variation in the size and colour of P. strombi, and in the form of the skin papillae, especially those generally termed ‘holdfasts’ or ‘adhesive papillae’, may be attributable to the size and type of shelter that is inhabited but experimental evidence is lacking. It follows that a similar degree of external plasticity to that recognised in P. strombi must be assumed for most, if not all, Phascolion, presently totalling around 45 species. Many Phascolion species have been erected on single or just a few specimens showing only slight differences of dubious systematic significance.

Taxonomically, the genus is very difficult and no satisfactory key to the species has yet been devised. As a first step, there is a need for definitions of subgenera, preferably based on internal characters which are not subject to environmental influences. To this end, the retractor systems of the north-east Atlantic species described below have been studied and compared with the type specimens of species from other areas.

By “post-larval stage” I wish to indicate that stage in the developmental history of Arenicola at which the full adult number of somites has appeared, and the body is already distinguishable into (a) an anterior chætigerous region, and (b) a posterior achætous region or tail, but in which the gills are not yet completely formed or have not yet even made their appearance.

Taxonomic diversity and temporal patterns in abundance of periphytic ciliate communities across taxonomic levels were studied to monitor water quality in Korean coastal waters during April 2007. Specifically we compared two methods based on an artificial substrate (glass slide): the polyurethane foam enveloped slide (PFES) and the conventional slide (CS) systems. The results demonstrated that: (1) the colonization patterns of the ciliate communities at all taxonomic levels showed a lower variability in the PFES system than those of the CS system; (2) The taxonomic diversity (Δ) and taxonomic distinctness (Δ*) were significantly higher in the PFES system than those in the CS system; and (3) all four taxonomic diversity/distinctness indices represented lower variability in the PFES system than those of the CS samples. These findings suggest that the PFES system is more effective than the CS system for measuring the colonization patterns and taxonomic distinctness parameters that are increasingly used as potential indicators of water quality. This conclusion supports our previous suggestion that the PFES system is a better tool than the CS system for monitoring water quality in the marine ecosystem, using periphytic ciliates.

Accounts have been given in previous papers (1925, 1926, 1928) of measurements of submarine illumination carried out near Plymouth by means of photo-electric cells. A further paper (1929, 3) recorded the results so obtained during 1928. An account is now given of photo-chemical measurements made in that year, simultaneously with the photo-electric measurements.

In other papers (Ford, 2 and 3) attention was directed to a study of the changes in length which occur during the transformation of the transparent eel-shaped larval clupeoid into the silvery and scaled adolescent fish. The change in position of the anus and fins relative to the vertebræ was considered in connection with the altering proportions of the different body intervals as development proceeds, and simple models were used to illustrate important features.

Now the freshwater eel has its transparent larval stage and metamorphosis. As in the clupeoid, length-proportions change during development, while anus and fins undergo marked migrations with respect to the myomeres. It was therefore thought to be of no little interest to analyse the length-changes during development in a manner similar to that adopted for the herring, sprat and pilchard. Professor Johannes Schmidt most kindly supplied me with material upon which to work, and I have made much use of data already published by him in reports on his great pioneer investigations. I have also drawn extensively from the data given by Dr. Leon Bertin in his paper on the migrations of the anus in the eels during ontogeny. I may be permitted to add that much which follows is suggestive in nature, rather than proven fact. Nevertheless, it should prove of interest in its direct bearing upon questions of fundamental biological importance.

Since 1921 hydrographic data have been collected by the S.S. Salpa and several merchant vessels, the records being published in the Rapport Atlantique and the Bulletin Hydrographique each year. A description of the conditions in the mouth of the Channel—the varying temperature, salinity, and movements of the water masses—during the years 1925–1928 was published in this Journal, Vol. XVI., pp. 791–820, and included a review of the objects of these investigations and the methods used in working up the collected data. This present publication forms a continuation of this. The same methods of dealing with the data have been used.

The characters widely used for identifying members of the Ampelisca diadema group of species (A. diadema, A. spinipes, A. tenuicornis and A. armoricana) are reassessed. Highly variable characters are discarded in favour of more stable ones. Both sexes of all four species known from the north-east Atlantic are figured and diagnoses and a key to the species are provided.

This paper describes the incidence and pathology of a copepod parasite (Sarcotaces sp.) in two species of deep-sea bottom-living fish. The fish Lepidion eques (Moridae) and Coelorynchus occa (Macrouridae) are common on the continental slope to the west of the British Isles at depths from about 400 to 1300 m and 700 and 2000 m respectively.

In both species the parasite was located beneath the skin. In L. eques it was found primarily on the head, whereas in C. occa it was present on the mid to lower flank, often close to the anal vent. Excision of the parasite from the host tissue showed it to consist of a pyriform sac filled with inky black fluid. Detailed histological investigations revealed the parasite wall to be a highly complex structure. Within the gut fluid shown to be of haematogenous origin, numerous copepod nauplii were often observed.

A pilot study was conducted to follow condition and swimming performances over two months using three samples of 50 juveniles of white sea bream, Diplodus vulgaris. The initial result indicated that the weight-length relationship followed the model; W=5.2xl0-3L349. According to this relationship, condition indices were estimated for each individual as the observed weight related to the computed weight. Measures of swimming velocities realized in an artificial flume show variations through time with an increase and decrease directly correlated to condition indices. Maximum speed of an individual was measured at 12.3 cm s1. Analysis of environmental conditions indicated that the decrease of condition index and swimming performances was related to bad weather which induced turbid water in juvenile habitats.

Individual identification using Hi8 video images was tested on the population of estuarine dolphins, Sotalia guianensis that inhabit the Cananéia estuary, south-eastern Brazil. Between June 2001 and August 2002, 25 different dolphins were identified by nicks on the dorsal fin (80%) and by the association of cuts and scratches on the dorsal fin and the body's dorsal region (20%). The existent marks were used to create an identification key to ease the matching between dolphins. The animals were present on 100% of the sampled days, and some of them were repeatedly registered at the same sector in the area, suggesting that although they occupy an extensive area, they use it in an intended way. When compared to researches that used photographs to identify cetaceans, the video images showed some loss of information, nevertheless the analysis could be done without impairment of results, therefore this method proved to be efficient.