A new genus of terebellid polychaetes is described, from material collected from living colonies of a stony coral (Mussismilia hispida) in the State of São Paulo, south-eastern Brazil. Articulatia is characterized by possessing notopodia from segment 5, neuropodia from segment 5 or 6 with double rows of uncini from segment 7 until near pygidium. Up to segment ten, notopodia with bilimbate capillaries; from segment 11 onwards two types of notochaetae are present, articulated chaetae, due to a deep cut at the sulcus of the third tooth, as well as capillary chaetae, both types with serrated blades. The presence of deep-cut chaetae is unique among all previously described terebellomorph polychaetes. This new genus is compared with other terebelline genera, and the phylogenetic analysis previously performed for the group is rerun, in order to determine the position of Articulatia within the subfamily. The type species of the new genus, A. aberrans, is also new to science and herein described.

Changes in total lipids and fatty acid profiles (FAPs) of gonad, digestive gland, mantle and muscle of the tropical scallop Nodipecten nodosus were examined during coastal upwelling and upwelling relaxation periods. Total lipids were most abundant in digestive gland, and intermediate in female gonad. Multidimensional scaling analysis of similarities (MDS-ANOSIM) and similarity percentage analyses (SIMPER) revealed significant changes of FAPs of the four tissues during the upwelling and upwelling relaxation periods. During both periods, SIMPER analysis revealed an internal similarity index greater than 90% for FAP of each tissue. However, during upwelling the gonad-FAP showed a lower dissimilarity index with the digestive gland-FAP (10), than with muscle-FAP (11) or mantle-FAP (13). In general, during upwelling, the fatty acids 16:0, 18:0, 16:1 n-7, 20:5n-3, 22:6n-3 and total PUFAn-3 explained 42 to 63% of variance between tissues; during upwelling relaxation, these fatty acids together with 14:0 and 18:1 n-7, explained 46 to 64% of variance. During upwelling period, MDS-ANOSIM showed a close association between FAP of digestive gland and gonad, suggesting a rapid transfer of fatty acids between these tissues, and consequently, that N. nodosus follows an opportunistic strategy during this period. In contrast, during upwelling relaxation, the slow and continuous fall in total lipid contents of digestive gland (September to November) and the progressive reduction of MDS distances between FAPs of digestive gland and gonad (August until November), suggest a gradual transfer of lipids from digestive gland to gonad to support the gonad development observed during this period. This suggests that N. nodosus switches to a conservative strategy during the upwelling relaxation period.

Multiple locus allozyme heterozygosity has been shown to be weakly, but significantly correlated with certain fitness parameters in bivalves. Immune function of individual Mytilus edulis from the Menai Strait, Wales, UK was assessed monthly over one year (1997–1998) by measuring total blood cell (haemocyte) counts, differential haemocyte counts (% basophils and eosinophils), phagocytic capability (by zymozan uptake) and intracellular superoxide generation. Sampled mussels were also scored at 9 allozyme loci. Mussels were then grouped into multiple locus heterozygosity (MLH) classes and plotted separately against the different measures of immunocompetence. No significant association was present between MLH and total haemocyte count, phagocytic capability or intracellular superoxide generation. However, there was a significant association between MLH and the character (basophilic or eosinophilic) of circulating haemocytes (r2=0·057, P=0·002). Highly heterozygous individuals tended to have significantly more eosinophilic haemocytes circulating in the blood than highly homozygous individuals. Eosinophilic haemocytes are known to have a high capacity for phagocytosis of invading organisms and these results may therefore be interpreted as increased health (=fitness) in more highly heterozygous individuals.

Respiration rates normalized to chlorophyll a of laboratory cultures of Brachiomonas sp., Gyrodinium aureolum, Synechococcus sp. (clone WH 7803), Pycnococcus provasolii (clone W48–23) and Phaeocystis sp. showed a positive relationship with growth photon flux density (Ig). It is argued that this constitutes an energy conserving strategy of adaptation to conditions of low irradiance. The ratio of respiration to light-saturated rate of photosynthesis (R/Pmax) also showed a decrease with decreasing I. Algal cell size, within the investigated range (0·2 to 1380 pg C cell-1), showed little influence on biomass-specific respiration rates.

Chromosomes of Haliplanella luciae (=H. lineata) (Verrill) were studied by a simple method that involved examination of Giemsa-stained preparations. The preparations were made from early embryos after fertilization in the laboratory. This is the first report of chromosome number for the acontiate sea anemones. A modal diploid number of 32 chromosomes was observed in metaphase plates. The method reported here is applicable to studies of chromosomes of other Actiniaria in which external fertilization occurs, with mature gametes being released from individuals of both sexes.

The auto-fluorescence patterns of the medusae observed under a fluorescent microscope with blue light excitation allows to distinguish two species of Eugymnanthea, this even when they are still attached to the hydroid as small medusa buds despite the occurrence of a sex-dependant pattern in E. japonica. A total of four distribution patterns of green fluorescence, including non-fluorescence, could be found. Three of them are found in E. japonica, called ‘subumbrellar fluorescence type’ except for non-fluorescence, while another type is found in E. inquilina, called ‘umbrellar margin fluorescence type’. During the short life of the medusa the latter type remained invariable for up to six days in E. inquilina, while the pattern observed for up to seven days in E. japonica changed sometimes, but it always remained distinguishable from the pattern found in E. inquilina. Therefore, the fluorescence pattern is a reliable taxonomic character. Fluorescence was not found in unfertilized eggs, planulae 2–8 days old, parthenogenetically produced larvae, or in the hydroids of the two species. The auto-fluorescent and possible bioluminescent tissues of these Eugymnanthea medusae could have some unknown biological significance.

The post-larval stages of Ammodytes species captured in the young fish trawl and small-meshed nets during the cruises of s.s. Oithona in the year 1919 were separable into two well-defined series, A and B respectively. Details of the hauls of the trawl and nets with dates and localities are to be found on pages 210–212 of Mr. R. S. Clark's account of the cruises in the present volume.

Considering the adult forms of Ammodytes known to occur in Plymouth waters, it is observed that Ammodytes lanceolatus, Lesauvage, and Ammodytes tobianus, L. are frequently met with, but no record is to hand at present of the occurrence of Ammodytes cicerellus, Rafin., although the latter has been taken frequently in the Atlantic. In regard to the larvæ and post-larvæ, none comparable to those assigned to A. cicerellus by Louis Fage (1, p. 17) have been described previously as occurring in this district, nor have such forms revealed themselves in the material under present consideration.

In endeavouring to identify the post-larvæ of any species, a study of the characters of the adults is often of great help, but in the case of Ammodytes species the only features of the adult which seem to be of value in this respect are the number of vertebræ and the relative length of the head to the total length of the body, and even so these characters, on account of the difficulty of determining them, are not so helpful as they would appear to be. Other characters have therefore to be sought for, and the following are those by which Series A and B have been distinguished:—

Seven populations of Holothuria polii were sampled from the eastern and western Mediterranean coastal waters of Tunisia and screened electrophoretically for genetic variation at 11 allozyme loci. Six among the seven polymorphic loci were out of Hardy–Weinberg equilibrium (HWE) in at least one population. In the same way, the multilocus test showed deviation from HWE in all populations. These populations showed heterozygote deficiency. Genetic variability was relatively low. The number of alleles per locus ranged from 2.09 to 2.27 (average = 2.15), and the observed heterozygosity varied between 0.14 and 0.20 (average = 0.17). The observed overall differentiation among populations was slight but significant, with a mean FST value of 0.024 (P < 0.001). Pairwise FST values reflected the differentiation of the two populations, which were at the margins of the range sampled, from all the others. Our data suggest a population structure consistent with separation by Mediterranean Sea basins that might reflect different local biogeographical zones.

In intertidal poikilotherms with wide geographic distribution, physiological variations are ubiquitous, due to phenotypic plasticity and/or individual geographic variation. Using the grapsid crab, Cyclograpsus cinereus as a study model, acclimatization differences in respiratory physiology were evaluated among populations along the Chilean coast, covering a latitudinal gradient of about 2000 km. This species inhabits the supratidal zones and, therefore, is subject to constant immersion and emersion periods, producing physiological acidification due to CO2 retention, mainly in the branchial cavity. Individuals of six populations were collected along the coastline of Chile and were exposed to air for different time periods in the laboratory. The following parameters were measured: pH, Ca2+, Cl− and haemolymphatic lactate dehydrogenase (LDH) enzyme activity. Populations from lower latitudes were significantly different from those from central and southern Chile, with a higher haemolymphatic pH variation and higher Ca2+ level, along with lower levels of Cl− and LDH enzyme activity. This indicates that the populations from lower latitudes, which are subject to higher air temperatures during emersion, have a higher homeostatic capacity during emersion periods than those of intermediate and higher latitudes. This response seems to be determined by genetic bases due to adaptation to the local environment.

In order to elucidate the ecological significance of polychromatism in Idotea baltica (Crustacea: Isopoda), the distribution of the various phenotypes was studied for three consecutive years in a population from the Bay of Naples. The most abundant morphs were uniformis (males: 394%-100%; females: 24·6%-84·1%) and maculata (males: 0·59·8%; females: 0%·50%), their distribution varying throughout the year. The assessment of some biological characters (females size, fecundity and embryonic stages of development) did not show any differences accounting for preferential fitness of these phenotypes. Moreover, it was observed that phenotypic diversity in colour morphs followed seasonal changes in the substrate composition. In agreement with other investigators, it has been suggested that the camouflage function of polychromatism may have a fundamental role in the reduction of predation, and favour Idotea baltica colonizing a variety of changeable habitats.

We deployed jaws of the common thresher shark (Alopias vulpinus) on the seafloor at ~1000 m depth off Monterey California for 8 months. The jaws disintegrated, with all the hyaline cartilage disappearing, leaving some fragments of tessellated cartilage and the teeth. Two different Osedax species, O. packardorum and O. talkovici were found to have bored into the roots of some of the teeth, and were using the dentin pulp, which is rich in collagen, as a food source. The enameloid crowns of the shark teeth and the tessellated cartilage showed no signs of Osedax activity. This is the first demonstration of Osedax exploiting a source of food that is not bone. This raises questions as to the original food source of Osedax ‘bone worms'. Examination for the presence of Osedax in the skeletons and teeth of Mesozoic and possibly even Palaeozoic fossil sharks, bony fish and reptiles is warranted.

The South China Sea (SCS) is a biodiversity hotspot, however, most biodiversity surveys in the region are confined to shallow water reefs. Here, we studied the benthic habitat and fish assemblages in the upper mesophotic coral ecosystems (MCEs; 30–40 m) and SWRs (8–22 m) at three geographic locations (Luzon Strait; Palawan; and the Kalayaan Group of Islands) in the eastern SCS (also called the West Philippine Sea) using diver-based survey methods. Mean coral genera and fish species richness ranged from 17–25 (per 25 m2) and 11–17 (per 250 m2) in MCEs, respectively; although none of these were novel genera/species. Coral and fish assemblages were structured more strongly by location than by depth. Location differences were associated with the variability in benthic composition, wherein locations with higher hard coral cover had higher coral genera richness and abundance. Locations with higher algae and sand cover had higher diversity and density of fish herbivores and benthic invertivores. Fishing efforts may also have contributed to among-location differences as the highly exploited location had the lowest fish biomass. The low variation between depths may be attributed to the similar benthic composition at each location, the interconnectivity between depths due to hydrological conditions, fish motility, and the common fishing gears used in the Philippines that can likely extend beyond SWRs. Results imply that local-scale factors and anthropogenic disturbances probably dampen across-depth structuring in coral genera and fish species assemblages.

Spontaneous swimming activity of O-group common sole (Solea solea) was evaluated using a video-tracking system under laboratory conditions. An experiment was conducted during two consecutive days on individuals sampled in June, July, September and November (2004) in a coastal nursery ground (Pertuis Charentais, Bay of Biscay, France). The measured behavioural variables were: distance travelled and frequency of occurrence of burying, swimming and immobility. O-group sole showed a relatively clear circadian activity in line with the artificial light conditions (day, twilight and night). Swimming activity of O-group sole decreased drastically from June to July, thereafter remaining at a very low level in September and November. Such important changes reflect the transition between the exploratory behaviour of the post-colonization period and a well established sedentary behaviour remaining until the onset of winter. These results highlight the potential limitation in habitat use capacities of O-group sole once settled in coastal nursery grounds.

The aim of this work is to describe the skeletal morphology of the early stages of the colonies of Stylaster sp., settled on artificial panels placed along a coral reef in the Bunaken Marine Park (North Sulawesi, Indonesia). The youngest observed stage deriving from the planula settlement is represented by a well developed primary cyclosystem symmetrically budding two secondary cyclosystems in a very early phase of growth. Successively each cyclosystem starts its vertical growth producing new cyclosystems sympodially arranged. At the same time the basal disc of the first cyclosystem enlarges producing a flattened crust from which new colonies arise. Vertical and encrusting forms are considered different modalities to face the problem of space competition in marine benthic organisms. The colonies of Stylaster sp. grow using both strategies resulting in the asexual reproduction of several colonies from a single settled planula. The new cyclosystems originate as small volcano-like elevations having the centre filled with calcium carbonate. Gradually this calcareous matrix dissolves starting from its perimetric zone and leads to the formation of the gastrostyle and the ring palisade. It is plausible that the cells composing the stolon nets deeply pervading the calcareous structure are responsible for this skeletal plasticity.

A new species of Orthonectid, Rhopalura granosa from Heteranomia squamula L., is described. The female is fusiform, and about 190 to 230μ, long, and 55 to 75μ broad. The male is also fusiform, but less than half the size of the female, being only 87 to 95μ, long and 20μ broad. R. granosa is distinguished from all other known species of Rhopalura by the presence in the male of large refringent bodies in the anterior cone, and in the first row of cells of the second ring. The male of R. ophiocomce Giard, a species closely allied to R. granosa, has the refringent bodies in the cells of the second ring only.

The notodelphoid copepods parasitic within Ascidians have been generally ignored for a long time. In May 1932 the present writer collected a considerable number at Millport Marine Biological Station, and was amazed at the frequency with which they occur. It may be that the Clyde area is especially favourable to their development, or it may be that the season was particularly good, for about thirty specimens were collected of ten species, of which at least one—the subject of the present paper—was new to science. If this abundance of forms is indeed usual, it is difficult to understand why records are not more frequent, and it would be interesting to learn how frequently these fascinating and aberrant forms are lost in the course of class dissections of their hosts.

Stomatogenesis of the marine scuticociliate Metanophrys sinensis, collected from a molluscan culturing pond in Qingdao, China, was studied using protargol impregnation method. The morphogenetic sequence develops in the proter: the remnant of parental paroral membrane gives rise to the paroral membrane and scutica, and the three parental membranelles were inherited. In the opisthe: the paroral membrane, membranelles 1, 2 and the scutica originate from the parental paroral membrane, while parental scutica gives rise to the membranelle 3. This suggests that M. sinensis has a relatively similar morphogenetic pattern to the members of the genus Uronema.

On an intertidal mud flat in the Ria Formosa (southern Portugal) Abra ovata (Mollusca: Bivalvia) showed effective meiobenthic and macrobenthic dispersal (i.e. of individuals smaller and larger than 1 mm). This was important to compensate for mortality caused by shore crabs during summer. It was observed in the laboratory that A. ovata deposited eggs in capsules on the sediment surface; after 11–15 d at 20°C benthic juveniles of 210–220 (im shell length hatched from these capsules. A pelagic larval stage was missing. Large numbers of specimens of about 1 mm shell length colonized protected buckets between February and June.

Two ascidians have been collected in the region of Plymouth that do not fit the descriptions of known species sufficiently well to be identified with them. They are species of Trididemnum and Distaplia.

These genera are represented in waters around the British Isles only by Trididemnum tenerum (Verrill) and Distaplia rosea Delia Valle. If Trididemnum niveum should be a valid species and not a synonym for T. tenerum as considered by Hartmeyer (1924), it also is probably present. Accordingly, any species that cannot be identified with these forms must either be new, or must represent geographical extensions of species not previously recorded. In this last respect, the possibility of the Mediterranean Distaplia magnilarva reaching the western Channel must be considered. As the following discussions indicate, the conclusions are that the two forms described here cannot be properly identified with any of the above and are to be treated as new species.

Trididemnum alleni n.sp. is named after the late Dr E. J. Allen, so long the inspiring and humane director of the Plymouth Laboratory, while Distaplia garstangi n.sp. is so named as a small tribute to Professor Walter Garstang for his pioneering interest in the ascidians of Plymouth waters.

Trididemnum Alleni sp.nov.

Colonies are usually small, less than a centimetre in greatest length, and about 3 mm. thick. They are brilliantly white, an appearance retained even in preserved specimens of long standing. The surface is uneven. They are commonly attached to Eunicella and larger hydroids such as Antennularia at depths of from 10 to 30 m., and have been recorded with certainty only from the Plymouth area of the English Channel.