The sulphonium compound dimethylsulphoniopropionate (DMSP) is commonly found in temperate green macroalgae. To examine taxonomic and regional and local geographical patterns of DMSP production in Australasian algae, I collected 30 species of green algae from 14 sites in three regions, eastern Australia, Tasmania, Australia, and the North Island of New Zealand. The distribution of DMSP content was similar to that seen from other areas of the world. DMSP was found in high concentrations in Ulva and Codium spp. It tended to be undetectable or in lower concentrations in other members of the orders Bryopsidales and Cladophorales. There was no evidence for differences in concentrations among the three regions in the genera Codium and Ulva; however, the invasive subspecies of Codium fragile, C. fragile ssp. tomentosoides, had significantly higher concentrations of DMSP than the non-invasive subspecies. The herbivorous sea slug Elysia maoria had whole body concentrations that were not significantly different from those of its host alga C. fragile ssp. tomentosoides. The distribution patterns of DMSP in Codium spp. do not support the hypothesis that DMSP is used as an antioxidant in this genus. Based on the data collected here and previous reports from the literature, I speculate that one function of DMSP in these algae may be to deter herbivores.

A female Octopus macropus, the first ever observed spawning, attached eggs (4·0×1·2 mm, with a chorion stalk 4 mm in length) individually or in clusters to a hard substrate, and brooded them till hatching. Hatchlings measured 4·0 mm in dorsal mantle length, 5·5 mm in total length and were planktonic; their short arms had seven suckers each, the outer demi-branch of each gill had ten lamellae. The chromatophore pattern confirmed an earlier identification of young individuals from the plankton (Naef, 1923).

The Atlantic–Mediterranean transition zone between the Alborán Sea and the Gulf of Cádiz constitutes the most prominent marine geographic barrier in European waters and includes known phylogeographic breaks such as the Strait of Gibraltar and the Almería-Oran Front. A genetic shift in this area has been previously documented for the European littoral shrimp Palaemon elegans. Here we carried out a phylogeographic analysis with the congeneric and sympatric species Palaemon serratus to test for similar intraspecific genetic differentiation and geographic structure. This littoral prawn is distributed in the Northeastern Atlantic Ocean, the Mediterranean Sea and the Black Sea. We compared DNA sequences from the mitochondrial genes Cox1 and to a lesser extent from 16S rRNA of several Atlantic and Mediterranean populations. Furthermore, sequences from the nuclear gene Enolase were included for corroborating differences between Mediterranean and Atlantic individuals. A pronounced genetic differentiation was detected between the Mediterranean and Atlantic populations, amounting to 10.14% in Cox1 and 2.0% in 16S, indicating the occurrence of two independent evolutionary lineages. Interestingly, specimens from the Atlantic Gulf of Cadiz cluster together with the Mediterranean individuals, indicating that a biogeographic barrier appears to be located west of the Strait of Gibraltar.

It is only within comparatively recent times that it has been proved that the otoliths and scales of certain Teleostean fish can be used for the determination of their age.

Rings of growth, as they are called, are produced on these structures, and it is by counting the number that the age is ascertained, in much the same way as the approximate age of a tree may be determined by counting the annual rings.

Community parameters of diatoms have been used as useful bioindicators for bioassessment of both lentic and lotic systems. The influence of enumeration time periods on detecting community parameters of periphytic diatom assemblages within different exposure times was studied using an artificial substratum in coastal waters of the Yellow Sea, northern China, during the period May–June 2010. Samples were collected at a depth of 1 m, and were examined with different enumeration time periods. Enumeration time periods represented a significant influence on detecting the community features of periphytic diatoms, although no significant changes occurred in periphytic diatom community structure between two enumeration schemes (within 24 h and 24–48 h). The delayed enumeration (within 24–48 h) may result in the similarity of the communities being reduced 10–29%, and in species numbers decreasing and in abundance increasing with exposure duration, respectively. The diversity (richness, evenness and diversity of species) indices were significantly decreased in almost all samples with >10% standard errors at some exposure times by the delayed enumeration scheme. These results suggest that the delayed enumeration may have resulted in the species richness and individual abundance of periphytic diatoms significantly decreasing and increasing, respectively, and thus significantly affected the analyses of species diversity for assessing water quality in marine ecosystems.

Of the three species of the genus Squalus that occur in the Mediterranean Sea, S. blainville and S. megalops are very difficult to distinguish. This study assesses the variability in morphological features that have been used to differentiate between these species. Squalus were collected from stations within the 25-nautical mile Fisheries Management Zone around the Maltese Islands; 349 specimens were dissected and categorized into male and female, mature and immature, and individuals were randomly selected from each category to make up a sample of 169 specimens. For each individual, total length and first dorsal fin parameters were measured, and morphology of denticles isolated from the laterodorsal area, of the upper and lower teeth and of the chondrocranium was analysed. The first dorsal spine was shorter that the fin base in 93% of the specimens, which is typical of S. megalops; this character was not related to either gender or maturity. Chondrocrania with one lateral process (typical of S. blainville) and two lateral processes (typical of S. megalops) were present. Teeth from the same individuals showed morphological features that overlap between S. blainville and S. megalops. Both unicuspid (typical of S. megalops) and tricuspid denticles (typical of S. blainville) were observed on the same individuals. Twelve specimens (six having one and six having two lateral chondrocranial processes) were analysed genetically by sequencing of the mtDNA marker Cytochrome Oxidase Subunit I (COI). All resulted to be S. blainville showing that intraspecific variability in supposedly diagnostic morphological features is large enough to render these unreliable to tell apart these two species, especially in the field.

Three new species of Fritillaria are described from specimens collected by a remotely operated vehicle (ROV) between 180 and 735 m depth in Monterey Bay, California. Fritillaria rex becomes the largest species now described for this genus (trunk length up to 10 mm, tail length up to 18 mm). This species is characterized by five or six narrow muscle bundles on each side of the tail, slit-shaped spiracles, a spherical ovary and a cylindrical testis. Fritillaria amphigonadis (trunk length up to 5.2 mm, tail length up to 7.5 mm) is characterized by two narrow muscle bundles on each side of the tail, slit-shaped spiracles, paired spherical ovaries, and a unique pi-shaped testis. Fritillaria lucifer (trunk length up to 4.1 mm, tail length up to 7.0 mm) has 12 extremely thin muscle bundles distributed broadly across the tail, rounded spiracles, a spherical ovary and a U-shaped testis. An additional mesopelagic Fritillaria appears to be consistent with the description of the Mediterranean F. fage, but specific differences in pharyngeal cells, cellular patterns on the tail, and gonadal morphology suggest that the specimens from Monterey Bay are a new variety, F. fagei mbarii. Based on the relatively limited number of collections (i.e. only 20 specimens yielding four unique taxa), it would appear that the possible diversity of larvaceans that live below the surface mixed layer is significantly underestimated.

Invasive predators can have wide-ranging effects on invaded ecosystems and identifying the prey spectra and preferences of invaders are important steps in assessing their potential impacts on native biota. In this study, we investigated prey preferences of two invasive crab species (Hemigrapsus sanguineus and Hemigrapsus takanoi) that recently invaded Europe's shores and compared them with preferences of native shore crabs (Carcinus maenas) of similar size. In laboratory experiments, all three crab species preferred animal over algal prey. In general, sessile mussels (Mytilus edulis) were preferred over motile amphipods (Gammarus locusta) by all three crab species but amphipod predation was lower in the invasive compared with the native crabs. For the two invasive crab species, this pattern was the same in treatments where prey was offered separately (no-choice treatments) or simultaneously (choice treatments), while for the native crabs, mussel preference disappeared in choice treatments. The general preference of mussels by all three crab species suggests that local invasions of crabs most likely lead to increased competition among crabs. In addition, given that local densities of invasive crabs are often much higher than those of native crabs, predation pressure on native mussels can be expected to strongly increase at invaded sites. In contrast, local predation pressure on amphipods may be less affected by the crab invasions. Further field studies are needed to establish the magnitude of competition and predation pressure exerted by the invaders under natural conditions.

Many crustaceans with spatial segregation may present differential body coloration depending on the habitat they inhabit. Since crustaceans are unable to synthesize carotenoids, individuals must acquire them from their diet, so diet changes can modify individual coloration. The burrowing crab Neohelice (=Chasmagnathus) granulata inhabits the intertidal, from the uppermost parts of salt marshes to the lowest mudflat zones with a spatial segregation of different size-classes. They are primarily deposit feeders in mud flats and herbivorous–detritivorous in the salt marsh. We analysed the effect of intermoult length on the carapace colour of N. granulata, and the changes in carapace colour with crab size and zone. Crab colour varied between unvegetated and vegetated areas. Some of these differences were in part caused by colour changes related to crab size. Larger crabs show less intensive colours, and given that they inhabit the upper part of the intertidal a differential coloration pattern occurred between zones. In field experiments intermoult duration affected crab colour and some body regions analysed showed differences between zones unrelated to size.

Adult specimens of Capitulum mitella were collected in August 2011 in the intertidal zone of Dinghai, Fuzhou, Fujian, China (26°16′N 119°48′E). The morphology of the cypris larva reared under our conditions was determined using scanning electron microscopy (SEM). Special emphasis was given to the carapace, lattice organs, antennules, thoracopods and furcal rami. The whole carapace surface is sculptured by slender ridges demarcating rectangular or irregular polygonal areas with very fine pores. The cyprid possesses five pairs of lattice organs, arranged as two anterior and three posterior pairs. The second segment carries a preaxial seta 2 and a postaxial seta 2. The third segment carries a postaxial seta 3 outside the attachment disc, whereas a postaxial disc seta, an axial disc seta and two radial disc setae are located inside the attachment disc. The attachment disc is somewhat bell shaped. A series of slender cuticular flaps forms a distinct ‘velum’ around the base of the disc. The fourth segment carries four subterminal setae and five terminal setae. The cyprid bears six pairs of biramous natatory thoracopods consisting of a protopod (coxa + basis), a two-segmented exopod and a two-segmented endopod. The cyprid possesses a rudimentary abdomen and an almost completely cleaved telson with a pair of one-segmented furcal rami. The morphology and setation of the antennules of C. mitella resemble those of Balanus amphitrite (=Amphibalanus amphitrite) and Megabalanus rosa, but differ in some morphological details.

The population biology of the stout razor clam Tagelus plebeius is poorly understood, despite the species' current wide distribution, and the potential use of its Holocene shell deposits to infer past environmental and ecological conditions. This study investigates distribution and growth pattern of T. plebeius in the south-western Atlantic Mar Chiquita Coastal lagoon (37°32′S 57°19′W), Argentina. The population includes the oldest individuals (up to 27 years) reported so far with shell length up to 77.9 mm. A von Bertalanffy model with L∞ = 67.60 mm (95% CI = 64.55; 70.64), k = 0.181 year−1 (CI = 0.142; 0.218), and t0 = −0.77 (CI = −1.46; −0.08) best described their individual growth for the whole population. The higher density, growth rate k, t0 and maximum age and lower L∞ were in the low intertidal rather than in the medium intertidal, but there were no differences in density and age between medium and high intertidal. Given the results and the current knowledge on the effects of different factors influencing this species, we conclude that the distribution pattern and shell growth observed in our study reflect a response to metabolic necessities in combination with a strong influence of biological interactions.

Suspended organic matter in the oceans has been studied by many authors. In a review of the subject Parsons (1963) states that the occurrence of detritus particles in the oceans seems to be a universal characteristic of sea water. The greatest concentrations of suspended organic matter are to be found in turbulent inshore water masses.

An attempt was made to determine whether bistramide A (=bistratene A), a polycycloether with biological activity isolated from Lissodinum bistratum Sluiter, originates from the ascidian itself or from its symbiont Prochlorophyta. A high-pressure liquid chromatography assay carried out on the whole ascidian, the ascidian without a portion of its Prochloron and the Prochloron themselves gave concentrations respectively of 0.182,0.166 and 0.850%. In view of these results, as well as of the capacity of Prochloron to synthesize complex nitrogenous products and the cytotoxicity of these products, it is hypothesized that bistramide A originates exclusively in Prochloron.

This Autolytus has been known only in the form of Sacconereis, i.e. as the female stolon of an unknown Syllid. It was discovered in 1864 by a French zoologist, E. Claparède, at Port-Vendres (Pyrénées Orientales). According to the original figures and description it is an ordinary female individual in its general appearance, carrying a large egg-sac on the ventral side. The latter is “étranglé en 8” and turkish blue, the colour being due to the contained eggs. The body consists of about 60 segments, the dorsal surface of which is transversely banded by pigment of rose colour. Modification of the segments for swimming commences at the 9th setigerous segment and stops at the 21st. The following 40 segments (about) are not modified like the 8 in the first region just behind the head. The most striking character, by which the present stolon is distinguished from any other Sacconereis, is the presence of a pair of extra appendages in front of the head in addition to the median and lateral tentacles. Claparède states that the presence of these appendages, “qui n”ont été signalés chez aucune autre Sacconereide,” is by no means very astonishing, since there are two such ones in Polybostricus. Claparède clearly predicted their homology to the frontal lobes of the bifid antenna-like appendages in the male head. A. Malaquin (1893) actually explained the bifid condition of the frontal appendages of the male as due to their origin in the fusion of the lateral tentacles and the palpi.

The Monstrilloida form an aberrant group of Copepoda, distinguished by the complete lack, in the adults, of gut and mouth-parts. Sars (1921) divided the group into two sections, one being the Monstrilloida Cyclopimorpha, comprising a single family, now called the Thespesiopsyllidae (see Wilson, 1932), with two genera. The larvae of Thespesiopsyllus are gut parasites of ophiuroids (Bresciani & Liitzen, 1962). The second genus, Orientopsyllus, was described by Sewell (1949) from the Indian Ocean.

The second section, the Monstrilloida Genuina, comprises the single family Monstrillidae, various authors (Malaquin, 1901; Sars, 1921; Rose, 1933; Davis, 1949) differing in their division of this into genera. The present author regards the family as consisting of three genera, Monstrilla Dana, 1848, Thaumaleus Kroyer, 1846, and Monstrillopsis Sars, 1921, separated according to the criteria listed in Table 1.

In February 1965 larvae of Sabellaria spinulosa Leuckart removed from the plankton off Plymouth were reared for settlement experiments (Wilson, 1970b). Among the early stages in the rearing dishes there appeared several Sabellarian-type larvae which after a few days growth became conspicuous by their larger size, longer and straighter bristles, and by their general appearance being different from the more numerous Sabellaria larvae. It soon became apparent that they closely resembled a larva found in February 1927 which was described and illustrated many years ago (Wilson, 1929, p. 242, text figs. 4, 5), at which time it was attributed in all probability to Pallasia murata Allen, now Lygdamis muratus (Allen). Apart from two species of Sabellaria whose larvae were known, this was and still is the only other Sabellarian recorded from the coasts of Devon and Cornwall and adjacent offshore waters of the English Channel. In most years since 1965 varying numbers of this species of larva have been obtained in January and February, and have several times been reared through metamorphosis to early tube-building stages, these latter confirming by their distinctive characters that the above early attribution was correct. Work on a description of the development was begun but it was not until 1974, when work on colony formation of Sabellaria alveolata (L.) was virtually completed, that close attention could be given to it, and experiments on settlement carried out. In the meantime Bhaud (1969) had described and illustrated the development from larvae in winter plankton off Banyuls-sur-Mer, wrongly attributing them to Phalacrostemma cidariophilum Maranzella, while criticizing my identification of my 1927 larva.

Patterns of the distribution of intertidal fauna in relation to the diversity of habitats were studied in the UNESCO Man and Biosphere (MAB) reserve of the archipelago of Molene and Ouessant (west Brittany, France). A classification of environmental features was developed in order to determine species richness, abundance, biomass and trophic structure of the macrobenthic fauna in this intertidal area which covers 1120 ha. The four descriptors of the environment were: (1) substratum (rock, boulders, sediment, pebbles); (2) height on the shore, based on the macrophytic zones: Pelvetia canaliculata/Fucus spiralis; Fucus vesiculosus / Ascophyllum nodosum; Fucus serratus; and Himanthalia elongata/Zostera marina; (3) wave exposure (sheltered, semi-sheltered, exposed); (4) percentage of algal cover (<50%, >50%). Each type was defined by a four-figure number and matched to a map codification. A two-way analysis of variance (ANOVA) and a posteriori Newman-Keuls test (P=0.05) were applied to the series of species richness and biomass. Among the 308 species sampled, 40 represented 90% of the total biomass. Maximal number of species was reached in boulder fields in the Himanthalia zone, under exposed conditions and high algal cover. The lowest number of species was observed in pebble fields of the Pelvetia zone and in the sedimentary areas. Trophic structures were dominated by suspension feeders and herbivores at high levels on the shore and by carnivores at the lowest levels. High vegetation cover and wave-exposed conditions were shown to increase with increasing faunal diversity. Links between patterns of habitat distribution and faunal diversity and biomass in different spatial scales are discussed.

Various herbivorous invertebrates in seagrass beds are considered to be generalists in food use and their diets may temporally fluctuate according to the availability of food sources. We assessed whether food sources of herbivorous gastropods vary in a subtropical seagrass bed in Nagura Bay, Ishigaki Island, where coexisting seaweeds grow densely in spring but minimally in summer. Abundant gastropods and their possible food sources were collected in spring and summer of 2013 and 2015, and their stable carbon and nitrogen isotope ratios were measured. Between the two seasons, each possible food source had similar isotopic values, but all the herbivorous gastropod species in summer were more enriched in 13C than the gastropod samples in spring. The mixing models in SIAR (Stable Isotope Analysis in R) showed that the total contribution rates of seaweeds, i.e. rhodophytes, phaeophytes and chlorophytes, for all herbivorous gastropod species decreased from spring to summer; in contrast, the contribution rate of seagrasses increased. Linear Mixed Models showed that the seasonal variation in δ13C of the herbivorous gastropods was larger than that of the possible food sources, adding further evidence to the seasonal change in food sources of the herbivorous gastropods. This seasonal change in food use appears to correspond to the change in seaweed biomass, suggesting that herbivorous gastropods flexibly change their diets depending on food availability.

Autonomous acoustic data loggers can provide useful data on habitat use and activity patterns of vocalizing cetaceans. One type, the T-POD, uses filters that can be set to match the click characteristics of the target species. We used wideband acoustic recordings to document typical click spectra of bottlenose dolphins in Doubtful Sound, New Zealand, in order to develop T-POD settings optimal for that population. T-PODs at these settings made between 8 and 33 times as many detections as accompanying T-PODs set as in other studies of this species, confirming the value of optimizing settings for a particular dolphin population. Maximum detection range was 1313 m, and mean range of first detection was 593 m. Of 45 groups observed within 500 m of the T-POD, 47% were detected acoustically. Effective detection radius was estimated at 266 m (95% CI 222–317 m).

Five cyphonautes are described in Nordisches Plankton (Lohmann, 1911). Cyphonautes schneideri and C. borealis are larvae of Membranipora membranacea and represent extremes of variation in the shape of the shell. Cyphonautes balticus, like C. compressus which was very inadequately described, is the larva of Electra pilosa. The cyphonautes of these two species are the only ones likely to be encountered in the plankton of normally saline European seas. Cyphonautes barroisi is the larva of the brackish-water Electra crustulenta.

Cyphonautes balticus Thorson (1946), not Lohmann, is the larva of M. membranacea.

Larval synonymies for M. membranacea and E. pilosa are given.

The use of the Cyphonautes names is undesirable, and those of the polyzoan adults should be employed.