Multivariate analysis of qualitative and quantitative data from algal communities, collected at three coastal areas of the Aegean Sea in the upper infralittoral zone, has been carried out using the PRIMER software. The aim was to detect groups of species reflecting differences in environmental conditions. A multidimensional scaling of the results demonstrated the presence of three different groups of Cystoseira species, corresponding to different hydrodynamic conditions.

In a collection made with a 2 m stramin ring trawl at 47°03′ N., 5° 47′ W. on 4 July 1956, with 800 fathoms of wire out, I have found a new species of medusa. This specimen is in a comparatively good state of preservation except that the stomach is badly damaged.

The umbrella is hemispherical and the jelly is moderately thick. The form of the stomach cannot be described for certain. Parts of it are to be seen as narrow strips hanging down from the upper ends of three of the radial canals. One of these strips is continued for a short distance along the subumbrella surface towards the summit. It has the form of two short curtains with a space between them which leads into the radial canal. It thus seems quite possible that the stomach is i n fact an open cross with mouth lips extending along each arm as in Staurophora.

Dendrobranchiata shrimp taxonomic composition and spatial and temporal distribution on the Amazon continental shelf (ACS) were investigated along a transect between the sources of the Amazon and Pará Rivers, encompassing an extension of ~250 km towards the continental slope. Plankton was collected with oblique trawls (200 μm mesh size), and nine taxa were found; 59.4% were larvae (mysis or decapodid stages) and 40.6% were juveniles or adults. Acetes was negatively related to chlorophyll-a and temperature, and Luciferidae were positively correlated with months. This study provides novel information on the density distribution of dendrobranchiate shrimps, thus helping to pave the way to characterize a large-scale, hugely relevant area that is poorly studied. As in other tropical coastal areas, there is here an increase in number of taxa with increased distance from the coast. Luciferidae, Solenoceridae and Penaeidae were the most frequent families whereas Sicyoniidae and Sergestidae had the lowest frequency of occurrence nearer the slope. Despite the low larval density of penaeid shrimps, their presence in all months and at all sampling sites along the ACS proves the importance of this area for shrimps with socioeconomic relevance, as well as its importance as a nursery and growth habitat for dendrobranchiate shrimps.

This paper is one of a series on the fecundity of the plaice Pleuronectes platessa L. over a wide area of its geographical distribution and is concerned with the number of ripening eggs in the roes of female Icelandic plaice prior to spawning (see Bagenal, 1962, for references to other areas).

Thirty-eight plaice were caught by the Icelandic research vessel ‘Maria Julia’ on 23 and 24 March 1961 in the Midnessjor area. They were measured and weighed and the otoliths were extracted. The ovaries were preserved in modified Gilson's fluid (Simpson, 1951). I am very grateful to Mr Jon Jonsson who kindly made all the arrangements and Mr Gunnar Joakimsson who prepared the material in Iceland. The fish were very ripe and a few had developed translucent eggs, but spawning had not begun. The subsampling and statistical treatment of the results were the same as before (Bagenal, 1962). The otoliths, after being kept dry, were very difficult to read.

The Icelandic plaice are an isolated population, separated by deep water from the rest of Europe, and there are several spawning areas. currents move clockwise round Iceland and will carry the fertilized eggs and young larvae from Midnessjor and the S.W. coast spawning areas (Thomsen, 1948) to the good nursery grounds of Faxa Bay. Tåning (1929, 1948) has given accounts of the Faxa Bay plaice biology and suggests that ‘the eggs and tiny fry, which are found in the Bay in the spring months, seem mainly to come from the outside, for the greater part most probably from S.W. Iceland’. The eggs from the population offish considered in this paper, from Midnessjór, would drift into Faxa Bay which forms a good nursery ground.

Three methods of determining extinction coefficients of light in sea water have been compared: (a) on water samples contained in a Pulfrich photometer, (b) from brightness profiles determined by aerial photographic survey, and (c) by photoelectric underwater measurements. The ratios of extinction coefficients for green and red light as determined in 1945 by the Pulfrich photometer and by the brightness profile method are given in Table 3, columns 9 and 10. For green light the ratio is about i-8 and for red light 1-3.

The departure from unity is attributed to the geometry within a confined tube and, within the Pulfrich measuring assembly, of light rays scattered forward by particles present in sea-water samples. In the following year, 1946, comparisons were made between the Pulfrich method and the submarine photometric method of Atkins and Poole. The discrepancies were variable and even larger, the ratios averaging 3-8 for green light and 2-0 for red light.

The brightness profile and submarine photometric methods have not been directly compared, but, by comparing the two sets of determinations against the Pulfrich photometer, it would seem that extinction coefficients determined with the brightness profile method are about 2-2 times those determined by the submarine photometer in green light and about 15 times in red light.

Observations on samples from Spanish trawlers between September and November of 1995 revealed the presence of mated females of Loligo gahi (Cephalopoda: Loliginidae) from 164–285 m depth, in the Western area of the Falkland Islands Conservation Zone. 93.8% of the mature females, and 31.0% of the maturing ones, were mated. Deposition of spermatophores always took place in the oral membrane between the connectives of arms IV. The relationships between sexual maturation and copulation have been analysed, and the hypothesis of mating acting as a ‘trigger’ of the final sexual maturation in Loligo gahi females is proposed and discussed.

The enzymatic activity of aerobic and anaerobic metabolic pathways in Hyalinoecia artifex, a polychaete inhabiting the deep ocean, is reported. In addition, the allometry of its anaerobic and aerobic enzymatic activity is analysed. The aerobic metabolism was measured using the electron transport system activity technique (ETS), whereas the anaerobic metabolism was estimated using the activity of lactate dehydrogenase (LDH), octopine dehydrogenase (OPDH), alanopine dehydrogenase (ALPDH), strombine dehydrogenase (STRDH), and ethanol dehydrogenase (EtOHDH). The ETS activity was about 296.18 (µLO2 h−1 g−1), which is within the range described for polychaetes and other benthic metazoans. The anaerobic enzymatic activity expressed as µmol NADH min−1 g−1 was: LDH = 0.35, OPDH = 0.11, ALPDH = 12.66, STRDH = 10.78 and SDH = 0.48. The slope of the allometric relationship between specific aerobic metabolism and body size was −0.35. In the case of the allometric scaling of the anaerobic metabolism, only LDH presented a significant relationship, with a slope of b = 0.44. This positive scaling is consistent with the pattern emerging from the scarce literature on the allometry of anaerobic metabolism in marine biota.

The variation in convexity of the valves and the development of the pedicle opening in M. echinata is described in shells from a length of 1·2 mm to 13·5 mm and it is concluded that the differences in shell shape and form of the pedicle opening between M. truncata and echinata are of no more than specific value and that the latter species should be transferred from Pantellaria back to Megerlia.

Having attempted to investigate the Polychæte fauna of the Plymouth district during those favourable opportunities which have occurred during the past three years, I now put upon record some few notes respecting a small section of this interesting but extremely perplexing group.

The anatomy of Crenella decussata (Mytiloidea) is described. Individuals of this circumboreal species occupy granular crypts composed of sand grains held in place by mucus. The swollen basal region of the tubule is occupied by an individual, which connects to the sediment surface by two posterior tubes accommodating the inhalant and exhalant streams. There is reduction in musculature and, most importantly, anterior foreshortening of the outer ctenidial demibranchs and loss of the labial palps. This creates an anterior space in the mantle for the initial brooding of fertilized ova by females to the prodissoconch stage. Subsequently, these larvae are transferred to the exhalant tube of the crypt wherein they attach by a single fine byssal thread and are further brooded until the crawl-away juvenile stage is attained. Experimental studies of larval behaviour suggest that parental pheromones sustain the female/offspring bond. Newly hatched individuals responded to parental exhalant water by actively attaching themselves using a byssal thread. This response persisted for 28 days, but not after 55 days when, we suggest, the pheromonal response ceases and offspring are developed sufficiently to take up life in their own nests. Offspring retrieved from parental crypts and fed continuously reached an average shell length of 500 μm after 7.5 months. Brooded offspring thus appear to rely on embryonal energy resources until post-metamorphosis, after which suspension feeding becomes essential for further growth and development before the parental crypt is vacated.

Oxygen microenvironments adjacent to mussel (Mytilus edulis) and periwinkle (Littorina littorea) tissues were described using micro-optodes. For mussels these environments did not differ from the surrounding water body in either static or stirred conditions. Consequently no difference was seen in the MO2 of mussels within stirred and unstirred respirometers. An oxygen extraction efficiency of 30% was recorded for mussels in stirred and unstirred conditions. Under static conditions, periwinkles, with their weak ventilatory arrangements, were not capable of ventilating the surrounding water efficiently, and their tissues were surrounded by hypoxic seawater, even in fully aerated water. The resultant build up of oxygen gradients close to the tissue surface led to measures of oxygen consumption representative of hypoxic conditions in fully aerated, unstirred respirometers. Stirring of the contents of the respirometer immediately prior to final oxygen concentration measures was insufficient to counter this effect, which could only be avoided by continuous artificial stirring of the respirometric chamber water. These findings have considerable implications for study of the oxygen consumption of aquatic animals with limited ventilatory capacity, such as gastropod molluscs.

During ArcticNet surveys aboard ‘CCGS Amundsen’ in 2011, several subtidal stations located in Canadian Archipelago were sampled in order to study the composition of their benthic communities. Among the abundant material sampled, several specimens of rare polychaete species were found. Examination of this material showed four species not previously recorded in the area, and a new species described herein. Descriptions of these specimens are given in this work. Ophelina brattegardi Kongsrud et al., 2011 is characterized by a body composed of 27–28 chaetigers, by having the parapodia of the last four chaetigers shifted to the ventral side of the body, and by lacking branchiae in mid-body chaetigers. Macrochaeta polyonix Eliason, 1962 is unique within the genus in having several (instead of one or two) compound neurochaetae in anterior parapodia. Chaetozone acuta Banse & Hobson, 1968 is characterized by having spines from anterior third of the body and arranged in bundles composed of just a few chaetae. Chaetozone jubata Chambers & Woodham, 2003 can be distinguished from similar species by having very long capillary chaetae from chaetiger 2 or 3. Finally, Dialychone hervyae n. sp. is characterized by bearing four pairs of radioles with narrow flanges, by the bilobed tip of its first peristomial ring that projects beyond the collar, and by the paleate thoracic notochaetae bearing long mucros.

The family Syllidae, aside from representing the most species-rich family in Annelida, is characterized by a number of sexual and asexual reproductive strategies. With the exception of a few viviparous species, the subfamily Syllinae is characterized by schizogamous reproduction with pelagic larval stages and without parental care. Laboratory rearing of ripe specimens of Syllis rosea showed a different reproductive strategy, hitherto unknown in this subfamily. While male stolons rapidly degenerated after fertilization, female ones released large eggs in a gelatinous cluster attached to the middle-posterior chaetigers. The gel mass progressively compacted as a cocoon wrapped by the stolon body; 7 days after the deposition the larvae hatched out from the cocoon at the metatrochophore stage and the female stolon died after a few days. After hatching the larvae remained associated to the stolon, and young specimens of S. rosea survived up to the 3-chaetiger stage. Until now cocoon brooding by the stolon has only been reported for some Autolytinae. The production of gelatinous egg masses and parental care are known in basally branching clades within Syllidae, suggesting that this reproduction mode might retain some ancestral features. The scarce knowledge about reproductive cycles in Syllinae does not allow clarification whether this strategy is unique for S. rosea, or it occurs in other congeneric species. Further research is needed to understand possible relationships between sexual reproduction and phylogeny, stolon morphology and its adaptation to parental care, and ultimately between reproductive strategies and ecology.

Samples containing the marine ostracod Callistocythere badia were collected from upper shore rockpools on Filey Brigg, north-east England in order to examine the life cycle and genetic structure of the species. Reproduction occurred during spring/summer after which the adults died; juveniles over-wintered as A-1 instars. No males were ever found during the study. Analysis at three polymorphic loci (Gpi, Pgm and Mpi), showed significant deviations from Hardy–Weinberg equilibrium, and significant linkage equilibrium at and between all loci. The genetic data and absence of males confirm that Callistocythere is an asexual species. There was a significant positive relationship between the number of clones found within a pool and rockpool size, but not with algal habitat heterogeneity.

Two new Appendicularians: Inopinata inflata gen. nov., sp. nov. and Mesopelagicn caudaornata gen. nov., sp. nov., from the family Oikopleuridae (Lohmann 1915), subfamily Oikopleurinae (Lohmann 1896a), are described from specimens collected at mesopelagic depths (660–840 m) in Bahamian waters by the ‘Johnson-Sea-Link’ manned submersibles.

We describe a new genus and a new species of Polycladida, Namyhplana henriettae (Platyhelminthes, Euplanidae), which lives associated with the tubes of the bivalve Bankia martensi in the fjords of the South Pacific Ocean in Chile. This species is characterized by a ribbon-like body, light brown colour, anterior region devoid of pigment, few eyes, no tentacles, pharynx in the anterior region of the body with few folds, independent gonopores anterior to the medial body line, seminal vesicle strongly muscularized, digitiform penian papilla oriented posteroanteriorly, a curled vagina, and a large Lang's vesicle ventral to the intestine. A phylogenetic analysis of the Euplanidae, based on morphological characters, is presented. With the dataset used, the family Euplanidae does not seem to be a monophyletic group. The new species is closely related to Taenioplana teredini (also discussed here) which presents life-habit characteristics that are similar to those of the new species.

The analysis of changes in benthic community structure using multivariate techniques has been successfully applied to the detection and monitoring of impacts caused by oil related activities. A survey to assess the status of the benthos was performed prior to a scheduled exploratory drilling at Banco Sarmiento, a shoal located off the eastern mouth of the Strait of Magellan (south-west Atlantic). The aims of this study are to provide baseline data about the composition and structure of the subtidal macrobenthic assemblages, to analyse the relationships between biodiversity and environmental variables, and to compare its benthic assemblages with those of neighbouring areas. Multivariate analyses classified the stations in two major groups, one composed of relatively shallow stations with coarse sediments dominated by filter-feeders, and the other consisting of stations with a high proportion of sand and mud dominated by deposit-feeders. Poorly sorted sediments had higher species richness than well sorted sediments. Shallow stations showed the lowest taxonomic distinctness due to the occurrence of a high proportion of bryozoans encrusting hard substrata. A five-fold increase in biodiversity can occur at scales of tens of km, suggesting that generalizations on regional biodiversity patterns should be made with caution because of the different gears used during the collection of samples, and should be based on a thorough knowledge about the physical environment.

The mackerel fishery began off Plymouth in January, and boats from Yarmouth, Lowestoft, Newhaven, Brighton, Eastbourne, Hastings, Plymouth, together with a considerable number of Mount's Bay boats (Porthleven, Newlyn, and Mousehole) were engaged in the above fishery. Fish were found about the 13th January fifteen to twenty-five miles south-west of the Start Point, of a very fine quality, and were caught in considerable quantities for some few nights, catches from two lasts (20,000) down to few hundreds per boat. Westerly and south-west winds prevailing (strong breezes), very stormy weather set in, and fishing operations were interrupted for three weeks, when the boats got to work again, meeting only with light catches for some weeks, February and March were not very successful months, easterly winds set in and continued throughout above months, and practically nothing was done till latter part of March and beginning of April, when boats fell in with fish south-west of Eddystone fifteen to twenty-five miles. There fish were not so fine in quality as those of January, and appeared to be quite distinct from the latter. Some good hauls were secured, one last (being about the largest catch) to few hundreds per boat. The fishing continued up to May, and boats did fairly well, a good average earnings was obtained, prices kept up, especially during Lent.

Two new species of rotifers belonging to the Dicranophoridae are described from marine psammon collected at a depth of 30–40 m in the Mediterranean near the island of Elba, Italy. Myersinella uncodonta sp. nov. is characterized by two colourless eyespots; single, incurved acute apical rami teeth; two needle-shaped, slightly incurved elongate unci; manubria with forked head and crutched cauda; outer margin of rami angular postero-laterally. Myersinella longiforceps sp. nov. is characterized by two large red eyespots; a pair of extremely elongated, gouge-shaped apical rami teeth; two short, needle-shaped unci; manubria with forked head and double-crutched cauda; outer margin of rami rounded laterally, tapering towards fulcrum. This is the first report of the genus Myersinella from marine environments.

The “Scottish Marine Station for Scientific Research” has now been at work for a little over four years, so that the present seems a fair opportunity to inquire what has been accomplished by its means. The object of the present article is to supply this information, and to show to what extent the results obtained have justified the expectations of its promoters.