Sargassum muticum (Yendo) Fensholt was first described from Japan as the forma muticus (sic.) of S. kjellmanianum Yendo. Subsequently, s. kjellmanianum and S. miyabei Yendo have been recognised as conspecific with dioecious reproductive structures. S. muticum is monoecious. The taxonomic history of S. muticum and confusions arising are presented.

The spread of Sargassum muticum to regions of the world outside of Japan is illustrated. A distribution map of S. kjellmanianum, S. miyabei and S. muticum in the western Pacific is also presented with a discussion of this selected species group. Further work is required to determine the exact extent of S. muticum in the western Pacific region.

The influence of photoperiodicity on hatching of Sepia officinalis was investigated under different experimental light-dark (LD) conditions. The results are viewed in relation to some relevant properties of the perivitelline fluid (PVF) and the egg capsule during embryonic development. In embryos of S. officinalis the transition from light to dark ap-pears to act as a 'Zeitgeber' or synchronizer. The embryos consistently hatched during periods of darkness, even when the duration of the dark period was short (1–4 h) and replaced part of the natural light period. The hatching rhythm was independent of the embryonic stage at which the experimentwas started. Embryos that developed under a given LD rhythm did not hatch at that rhythm if it was changed or eliminated. In the absence of an external LD rhythm the time to hatching increased. Lack of pigmentation in the egg envelope appeared to reduce the time to hatching. If embryos were exposed to a single dark period of 1–4 h significantly more hatched during darkness while a dark-pulse of ten minutes resulted in no hatching. At the end of embryonic development the egg capsule of S. officinalis becomes thinner due to the expanding PVF. Absence ofthe envelope did not affect embryonic development but dramatically increased mortality and prema hire hatching (96%). Spectrophotometrical investigations indicated that light between 200 and 900 nm is absorbed similarly by the envelope and by female ink. The function of pigmentation in the envelopes remains obscure.

Ecologists examine diet composition in order to assess the spatial and temporal variations in interactions between species, the impact of different species traits on the ecological network structure, and the long-term effects of the removal of different species by small-scale fisheries. In this study, our goal was to compare the diets of silky sharks (Carcharhinus falciformis) and scalloped hammerhead sharks (Sphyrna lewini) off the south-west coast of Mexico in order to infer their diet preferences and spatial distributions. We sampled 164 S. lewini (96 stomachs had food, 68 were empty) and 183 C. falciformis (30 stomachs had food, 153 were empty) in Puerto Madero, Chiapas in 2011. The large number of empty stomachs may be the result of using longline fishing gear, which causes high stress resulting in regurgitation. Based on the index of relative importance (%IRI), the fish Chloroscombrus orqueta (IIR = 27.7%) was the most important species in the diet of S. lewini, while the squid Dosidicus gigas (IIR = 34%) was the primary prey of C. falciformis. Levin's index (Bi) and Shannon's index (H′) confirm that both sharks are generalists, as in other regions. The trophic levels of S. lewini (TL = 4.1) and C. falciformis (TL = 4.2) are characteristic of tertiary consumers; meanwhile, the Morisita–Horn index indicates low interspecific overlap between all categories. These results confirm that these two sharks have different foraging preferences or movement patterns; thus, there is no trophic overlap between species as they play unique roles in the ecological network off the south-west coast of Mexico.

Sponges (phylum Porifera) are important components of the benthic marine fauna known for their interactions with vertebrates and a large number of invertebrates seeking for food, shelter or substrate for attachment. Studies on this subject, however, were restricted only to the macrofauna inhabiting sponges of the class Demospongiae. In the present work, we describe the macrofauna associated with a calcareous sponge in Brazil, Paraleucilla magna. Individuals of this allegedly non-native species were monthly collected during one year in Rio de Janeiro (Brazil). Fifty-one taxa representing ten animal phyla were found associated with P. magna. The most frequent and abundant taxa were Crustacea, Mollusca, Polychaeta and Bryozoa, while echinoderms, cnidarians, ascidians, nemerteans, platyhelminthes and sponges were less frequent or even rare and less abundant. Juveniles of several taxa and pregnant females of Crustacea were found associated with P. magna, but these associations were not exclusive. The macrofauna associated with P. magna did not present a clear seasonality, although it was possible to observe a change in the community composition alongside the year. The volume of the sponges was significantly related to the diversity index (H′) and number of taxa, but not with evenness (J′) and number of individuals. Our results show that P. magna is used as a substrate for attachment and/or shelter by its associates and that most of these associations are just opportunistic. The data presented here reiterate a previous proposal that sponges are important biodiversity reservoirs and that they should be seriously considered in conservation programmes.

Exploration of the New England and Corner Rise Seamounts produced four new species of chrysogorgiid octocorals with the spiral iridogorgiid growth form. Three species are described as new in the genus Iridogorgia and one is described in the new genus Rhodaniridogorgia. Both genera have representatives in the Atlantic and Pacific Oceans. Iridogorgia magnispiralis sp. nov., is one of the largest octocorals encountered in the deep sea and seems to be widespread in the Atlantic.

Counting the numbers of phytoplankton organisms in water samples is time-consuming. A knowledge of the kind of organisms present and their relative numbers is essential, but it is useful to have in addition a measure of the quantity of organic substance present. A number of methods have been suggested for measuring the standing crop of phytoplankton and these have been summarized recently by Strickland (1960).

Samples of male Illex argentinus were taken from the catch of a Japanese squid jigging vessel on the Patagonian Shelf during March 1986 and an analysis was carried out on the morphometrics of the somatic and reproductive organ systems in relation to maturation. The data show that growth and maturation occurred simultaneously during most of the time that Illex argentinus males were on the feeding grounds over the southern Patagonian Shelf. In a squid of a ‘standard’ mantle length the whole body mass increased relative to mantle length during maturation and this could be attributed to the increase in mass of the reproductive and accessory reproductive organs. During maturation the mantle and digestive gland mass showed no significant change relative to mantle length. The mass of the head increased and the mass of the viscera decreased relative to mantle length. In male Illex argentinus, as in the female, the energy and nutrient resources for maturation are derived from the squid's food and during the course of maturation there is an increasing shift of emphasis from somatic growth to production of gonad and accessory reproductive organs. The proportional investment of body mass in reproductive and accessory reproductive organs predicted for a fully mature male Illex argentinus was less than half that of the female.

Studies by many workers on the subtle ecological relationships of marine organisms suggest that the distribution of these organisms may be controlled, at least in part, by trace organic substances in their environment. These substances may range from ‘toxins to vitamins and hormones’ (Lucas, 1955). Saunders (1957) has reviewed the interrelations ofdissolved organic matter and phytoplankton and considered the possible roles of organic metabolites in the growth of the algae. The presence of several vitamins, for example, B12, thiamin, niacin and biotin, has been demonstrated in natural waters, but the possible occurrence of plant hormones has not previously been considered.

Rafting on floating macroalgae is a common dispersal mechanism of marine benthic invertebrates. Most benthic macroalgae are inhabited by diverse epifaunal communities but not all organisms may be adapted to live on floating algae. In particular, knowledge about the immediate effects of algal detachment on the associated biota is limited. Herein, we studied the composition of the communities of mobile invertebrates on benthic thalli of Ascophyllum nodosum and compared it with detached thalli that had floated for short periods. The community of the mobile invertebrates changed significantly within the first minute after detachment of the algae and showed decreased diversity and a tendency towards reduced abundances in most taxa. However, during the subsequent two hours of floating at the sea surface the species composition did not change further. A comparison of the size-spectra of the gastropod Littorina obtusata from attached and detached algae did not reveal differential migratory activity among size-classes of these gastropods. Most of the species encountered in this study are common rafters in coastal and offshore waters, which are well capable of holding onto floating seaweeds. Therefore, our results indicate that the animals actively abandoned the macroalgae immediately after detachment. A benefit of this behaviour may be to avoid increased predation risk in the open water. The fact that individuals remain associated with their algal host after detachment indicates the importance of rafting dispersal for a great variety of phytal species that might lead to range expansion and regional population persistence through metapopulation effects.

Recent molecular studies have shown that the sponge order Haploslcerida is polyphyletic as the freshwater sponges appear to be more closely related to other demosponges than they are to the marine haplosclerids. Within the marine haplosclerid clade relationships viewed via 18S and 28S rRNA gene phylogenies suggest that the suborders and many families and genera are also polyphyletic. However, both of these genes are on the same locus and do not evolve completely independently. We have analysed mitochondrial Cytochrome oxidase 1 gene fragments from 44 species of marine Haplosclerida and show conclusively that the classification of this group needs complete revision. Molecular data show a very complicated phylogeny supporting very few morphological hypotheses and little geographical pattern. However, the molecular data contain a great deal of phylogenetic signal at many taxonomic levels and support phylogenies drawn from the other genes.

Regular monitoring of the status of cetacean populations is essential for conservation, policy and management. By using a passenger ferry as a scientific research platform, this study provides information on seasonal, annual and longer-term changes in the occurrence of three cetacean species along a relatively fixed transect through the English Channel and the Bay of Biscay. Data were collected over an 11 year period through the Biscay Dolphin Research Programme (BDRP). Surveys were conducted every month from 1996–2006 between Portsmouth, England and Bilbao, Spain by a team of experienced observers using standard techniques. From a 0.125° by 0.125° grid, cells were surveyed in each year and where each species was recorded they were identified using a geographical information system (GIS). A rapid analytical method—species occupancy (defined as the proportion of surveyed cells that a species was detected in)—was used to assess whether there were any trends in occurrence over time for three cetacean species. From this analysis, a significant trend to increasing occurrence of harbour porpoises in summer months in the English Channel was identified. There were also increases in the occurrence of common dolphins in the English Channel in winter months and striped dolphins in the Bay of Biscay in winter months corresponding with a decrease in summer occurrence, across the study period. However, while consistent, these trends were not significant.

Although the larva of Porcellana is one of the earliest known decapod larvae and at a later date the different stages of P. longicornis were well described by Sars (1889), there is yet much that is unknown. Few larvae have been actually hatched from the egg and in no case has the number of larval stages been definitely ascertained. In order to fill in some of the gaps in our knowledge a detailed study of the two common Plymouth species was begun (P. longicornis and P. platycheles). Unfortunately, war conditions made it difficult to obtain material and many specimens were lost as the result of air-raids; it was therefore not until the summer of 1942 that the work could be finished.

It is now possible to distinguish between the two species in all stages. Both have been hatched from the egg, larvae from the plankton have moulted and the post-larvae have been obtained from the last larvae. A comparison with Gurney's (1938a) notes on the species from the Red Sea and his general comments on the larvae of the genus and its relatives (1942) is of much use. These, with the first larvae of Petrolisthes armatus hatched by myself at Bermuda and certain larvae described by other workers, have made it possible to make some progress in the elucidation of the relationships of the larvae.

Porcellana longicornis and P. platycheles are both common at Plymouth; but whereas the latter is confined to coastal waters and lives between tidemarks and down to about 3 fathoms, the former has a much wider range and although occurring withP. platycheles between tidemarks extends to well beyond the Eddystone grounds.

The concentrations of organophosphoric acid triesters (OPEs) in water samples from Maizuru Bay were in the range of 3.0–62 ng/l. In general, the concentrations of OPEs were found in the order of TBXP > TDCPP > TCEP > TBP > TCP > TPP > TEP. The organophosphorous pesticides (OPPs) diazinon, fenitrothion, iprobenfos and chlorpyrifos were detected in water samples. The concentrations of OPEs in sediment from Maizuru Bay were in the range of <0.5–56 µg kg−1 dry weight (dw). Among OPPs, diazinon in sediment samples were in the range of 1.8–71 µg kg−1 dw. However, the detection frequencies of fenitrothion and chlorpyrifos in sediment were low. The concentrations of OPEs in mussels from Maizuru Bay were in the range of <1–34 µg kg−1 wet weight (ww). The concentrations of OPEs were found in the order of TBP > TDCPP > TCP > TBXP = TPP = TCEP. Pesticides were detected in mussels, but these concentrations were lower than the acceptable daily intake (ADI) values. The partition coefficients between water and sediment (Kws) of diazinon and fenitrothion were 200–1300 and 200–300, respectively and the partition coefficients between water and biological samples (Kwb) of diazinon and fenitrothion were 700–3300 and 450–700, respectively, suggesting that these pesticides accumulate in biological samples at higher rates than in sediment.

Using light microscope histology and scanning electron microscopy, the secretion, storage and discharge of copious quantities of mucus has been demonstrated in the algadwelling harpacticoid copepod Diarthrodes nobilis (Baird). The mucus is secreted by cells closely associated with large haemocoelomic reservoirs, located in the cephalothorax and urosome, which store the mucus prior to its discharge through large integumental vents (up to 38 μm in greatest dimension). A denned behavioural sequence is recognized whereby the animal utilizes discharged mucus to construct an enmeshing capsule. Late stage nauplii are also capable of capsule fabrication.

The mucus bag presumably, acts as a rich and rapidly degradable substrate to marine prokaryotes and is therefore rapidly colonized; suspended organic and inorganic materials are also trapped by the mucus. Observations on gut contents and browsing activity of capsule inhabitants indicate a direct trophic dependence of D. nobilis on the bacteria and organic agglutinations that adhere to the mucus. Utilization of such nutritive materials supports a ‘mucus-trap’ hypothesis recently proposed as a feeding strategy in meiobenthic nematodes.

Several Gobius species and also Aphya and Crystallogobius are common near Plymouth, from up the estuaries in the neighbourhood of Saltash to the west and Chelson Meadow to the east, as far as the open sea, well beyond Rame Head and the Eddystone Lighthouse. It has, however, always been difficult to determine the young of the various species as they usually differ very little from one another and it is hoped that the following notes may be a help in the elucidation of the subject.

A method, suitable for routine use, of determining total iron in sea water is described. The water is acidified to about o·13N with hydrochloric acid and is heated for 5 h in an autoclave at 140°C. Iron is determined absorptiometrically with 1:1 phenanthroline after reduction with hydroxylamine hydrochloride.

Tests of the method, collection and storage of samples and the variability of results are described.

Iron contents of water samples from the English Channel and the Bay of Biscay are reported.

Statoliths of the jumbo flying squid Dosidicus gigas (Cephalopoda: Ommastrephidae) in the eastern Pacific in 1995, 1996 (non-El Niño years) and 1997 (El Niño year) were analysed to observe whether unusual temperature increases due to El Niño was recorded in the concentration of trace elements. In addition to calcium (the major element), trace elements of manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), and strontium (Sr) were detected. Strontium concentration in the calcified tissue of some aquatic animals changes with environmental variables. However, yearly comparisons revealed that Sr concentration did not significantly differ between the El Niño year and non-El Niño years. Instead, the Sr concentration differed with squid habitats. Strontium concentration in statoliths of D. gigas from Peruvian waters (high salinity) was significantly higher than those from Costa Rican waters (low salinity) regardless of El Niño.

Some examples of relationships between hydroids and epibionthic diatoms from the Mediterranean Sea are described, verifying the kind of interaction existing between the two partners. The athecate Eudendrium racemosum hosts an extremely rich diatom assemblage, mainly comprising Licmophora spp., Amphora spp. and Cocconeis spp. On the contrary, only adnate growth forms (Cocconeis pseudonotata, C. dirupta) were observed in diatom communities growing on the external side of thecate species Campanularia hincksii, Clytia linearis and Synthecium evansi. Some diatom species (Cocconeis notata, Cylindrotheca sp. and Navicula sp.) are able to survive in the intrathecal microenvironment. They live in the narrow space between hydrotheca and polyp, receiving protection and probably using the nutrients produced by hydroid metabolism. Sunlight can penetrate through transparent thecae and reach the diatom layer, making photosynthesis possible.

The Asian date mussel, Musculista senhousia (Mytilidae), is a good example of a species that has dispersed outwards from its native area through human-mediated transport, establishing sustainable populations in distant parts of the world. The date mussel, which is endemic in the Western Pacific region, appeared and became very abundant in the Sacca di Goro, a brackish lagoon in the Po River Delta (northern Adriatic Sea, Italy) in the early 1990s. Effects of M. senhousia on macrobenthic biodiversity were assessed over a ten year time period. At the study site, the increase in abundance and spread of M. senhousia resulted in an alteration of the pre-established macrobenthic community. Changes in benthic dynamics seemed apparent, through the inhibition of epifaunal, suspension-feeding taxa (Ficopomatus enigmaticus, Mytilaster minimus), and the enhancement of detritivores (Neanthes succinea, Streblospio shrubsolii, Microdeutopus gryllotalpa). It is hypothesized that the Asian date mussel was initially successful because it exploited a naturally disturbed, sparsely occupied environment, rather than interjecting itself among and displacing existing species. Musculista senhousia acted, at least initially, as a colonizer rather than an invader.

Improved coral cultivation will facilitate the reduction of wild harvesting, reef restoration, preservation of biodiversity, and the use of corals as model experimental organisms. In this study, we examine species-specific responses in growth and survival of corals from the effects of light, water motion and artificial (i.e. non-living aquarium trade) food supplements. Three species representing distinct, diverse and abundant coral genera were chosen (Montipora capitata(Mc), Porites compressa (Pc) and Pocillopora damicornis (Pd)) for three experiments to examine: (1) the interaction of water flow and light on growth and survival of Mc and Pc; (2) the effects of artificial foods on Mc, Pc and Pd; and (3) the effects of increasing dosage of artificial foods in an open system on Mc and Pc. Pc thrived at the highest light levels with low flow, while Mc exhibited bleaching and reduced growth in the same conditions and grew best in shaded treatments. High constant flow (~11 cm s-1) resulted in slightly less overall growth than low constant flow (~4 cm s-1). Some artificial foods resulted in a significant increase in growth in Mc and Pd, but not in Pc. These combined results suggest that Mc may be more heterotrophic than Pc. This study illustrates that each species has unique requirements for optimal growth conditions that can be determined by relatively simple and low cost experiments, but that ideal conditions for one species might not be generalized to others.