We investigated the influence of the Changjiang diluted waters (CDW) on the distribution of nanophytoplankton (<20 µm) abundance and biomass in the northern East China Sea (ECS) during two research cruises conducted in the summers of 2010 and 2012, using flow cytometry. Each group of nanophytoplankton responded differently to the distribution of the CDW. In the surface layer, Synechococcus 1 which has low orange fluorescence, a major component of summer nanophytoplankton, were more abundant under the large extension of CDW to the northern ECS in August 2010, whereas the abundance of other groups including Synechococcus 2 which has high orange fluorescence, and pico- and nano-eukaryotes (0.2–2 and 2–20 µm in diameter, respectively), dramatically increased under the small extension of CDW in August 2012. The subsurface chl-a maximum layer became more developed under the small extension of CDW, and was dominated by nano-eukaryotes. During two study periods, environmental characteristics in the CDW also showed annual variations, with higher seawater temperature, lower salinity, and higher nitrate concentration in the surface layer of the CDW in August 2010. The summer distributions of Synechococcus and nano-eukaryotes were likely to be limited by low salinity and high temperature, respectively, indicating that phytoplankton distribution could be influenced not only by the extension level of the CDW but also by the change of the environmental characters of the CDW.

The loss of external tags is one of the biggest problems in mark-recapture research. An evaluation of tag loss is therefore required to improve tagging methodology, select appropriate tag types, and accurately estimate population status and dynamics. We estimated tag loss probability of double-tagged green turtles (Chelonia mydas) nesting at Redang Island, Malaysia (05°49′ N 103°00′ E), from 1993–2014. For both titanium and Inconel tags, we found a tag loss pattern with a high initial tag loss rate that decreased to an asymptote near a constant value above zero. The initial tag loss probability for titanium tags was higher than for Inconel tags, and titanium tags were lost earlier than Inconel tags in more individuals when both types of tags were attached. In addition, comparison of the tag loss probability of Inconel tags attached during the period when tagging staff changed every year to that when senior tagging staff were not changed, indicated that lack of consistency in tagging staff affected the application of at least one of two Inconel tags. Estimated tag loss probability was incorporated into a recapture model, and annual survival probability was estimated to be 0.893 (95% confidence interval: 0.857–0.921).

This study intends to reliably estimate the general status of the benthic and the epiphytic foraminifera community related to each studied seagrass ecosystem (Posidonia oceanica, Cymodocea nodosa and Halophila stipulacea) distributed in different shallow sites in the coastal archipelago of Kerkennah (Gulf of Gabes, Tunisia) during winter. We were able to first sort and subsequently identify some characteristics conditioning their behaviour. Twenty-four species of foraminifera were encountered. Among them, three epiphytic species identified on these seagrass leaves had a much lower abundance than those in the sediment. We were interested in highlighting the foraminiferal community related to Halophila stipulacea, since this seagrass species is newly introduced into the Mediterranean sea. Thanks to the statistical study, we were able to identify the favourable habitat for epiphytic and benthic foraminifera among the three seagrass ecosystems. A correlation between the identified foraminifera species and some environmental parameters was addressed using a variety of software.

This study investigated the emission of subaquatic noise from recreational tourism motorboats, schooners and a sea-bottom mounted water pump. Analyses demonstrated alterations in several whistle (IF: t = 2.42, P = 0.015; FF: t = −2.22, P = 0.025) and calls patterns (MIF: t = −3.13, P = 0.001; MAF: t = −3.49, P = 0.0005; FD: t = −2.21, P = 0.027; D: t = 2.89, P = 0.004), caused primarily by motorboats. Duration of clicks was also modified (D: t = −3.85, P = 0.0001), mainly by the water pump. The frequency range of all noises (0.43–35.8 kHz) overlaps that used by dolphins (1–48 kHz), causing sound emissions changes, with a considerable increase in number of whistles and a reduction in clicks trains. These changes may be a strategy developed by these dolphins to overcome the noise band. Mitigation measures, such as boating regulations and environmental education for the local community, boaters and tourists are needed to conserve the species. The Guiana dolphin population is apparently already suffering, evidenced by diminished residence time and reduced number of individuals entering the inlet during the presence of pleasure craft.

Octopus mimus is the main octopus targeted by the small-scale fishery in the Eastern Pacific. Commercial catches of octopus from the Reserva de Producción Faunística Marino-Costera Puntilla de Santa Elena (REMACOPSE) Marine Protected Area in Ecuador were sampled from July to December 2013 in order to describe the reproduction and population structure of this octopus. The 4171 sampled octopuses ranged from 56 to 250 mm in mantle length (ML) and 45 to 3178 g in body weight (BW). Mean octopus weight did not change monthly. Males were mostly mature while the majority of females were immature. Presence of some mature and a few spent females in all months sampled suggests that the population shows an extended spawning period. No spawning peak could be properly defined. Sex ratios did not significantly shift from the expected 1:1 in most samples. Females mature at a larger size (1234 g, BW; 165 mm, ML) than males (487 g BW; 114 mm ML). We recommend considering a minimum legal size of 1200 g BW. A year-long sampling programme for O. mimus should also be completed in order to detect any spawning peak.

Harmful algal blooms caused by raphidophyte species of the genus Chattonella (i.e. Chattonella antiqua, Chattonella marina and Chattonella ovata) have been documented in temperate coastal regions around the world. To understand the effects of physicochemical factors on bloom development of Chattonella spp., we investigated the variations of vegetative and resting cells (i.e. cysts) of Chattonella spp. and environmental variables in two coastal environments, Uranouchi Inlet (extremely closed) and Nomi Inlet (semi-closed), with contrasting enclosed natures. Although the vegetative cells and cysts of Chattonella spp. were distributed in both coastal regions, the densities were remarkably higher in Uranouchi Inlet than in Nomi Inlet. The mud content in the sediments of Uranouchi Inlet was also higher than that in the sediments of Nomi Inlet, meaning that fine particles such as cysts are likely to accumulate in the former region. Because of the extremely closed nature of Uranouchi Inlet, warm oceanic waters of the Kuroshio Current penetrate the inlet only infrequently. These results suggest that the closed nature of coastal regions is an important factor influencing either water exchange or the resultant accumulation of Chattonella cells in coastal environments.

The morphology of the first zoea of Gnathophyllum elegans is described from laboratory-reared material for the first time and analysed in detail with light and scanning electron microscopy. For systematic reasons, morphological characteristics in G. elegans are compared with those in Gnathophyllum americanum, Periclimenes amethysteus, a representative of the subfamily Pontoniinae and the closely related Hymenocera picta (Decapoda: Caridea: Hymenoceridae). We observed differences in the morphology of both Gnathophyllum-larvae, such as the number and arrangement of certain setae. Thus, larvae of the two Gnathophyllum species can be readily distinguished from each other. Further differential diagnosis with P. amethysteus confirms a high similarity between Gnathophyllum-larvae and larvae in the subfamily Pontoniinae, as already mentioned in earlier publications. The systematic relationships of the Gnathophyllidae, Hymenoceridae and Pontoniinae are discussed based on zoeal characters.

Monitoring the spread of non-indigenous species is fundamental to study global warming effects on marine biodiversity. A valuable tool is represented by the continuous updating of the geographic range expansion of non-indigenous species. Lamprohaminoea ovalis is a Lessepsian mollusc initially recorded in the Mediterranean Sea in 2001. This paper reports its range expansion over the last 20 years related to water warming. The first record of Lamprohaminoea ovalis from the Ligurian Sea (NW Mediterranean) is also reported. Two individuals (about 10 mm length) were observed on a sub-vertical rocky bottom at 26 m depth displaying potential trailing behaviour. This recent finding extends the currently known distributional range of Lamprohaminoea ovalis, representing the northernmost occurrence of this non-indigenous species in the western Mediterranean Sea.

Argopecten purpuratus was exposed to two different diets which reflected short term variations in quantity and quality of the natural food supply typical in bays of southern Chile. No significant differences of clearance rate were observed over different time periods at either of two food concentrations. The scallop reduced its clearance rate significantly when it was exposed to the higher food concentration. Pseudofaeces production occurred only at this high diet and the time factor had no significant effect on this process. The organic content of pseudofaeces was significantly lower than the organic content of the food, suggesting a pre-ingestive selection mechanism. Based on this capacity for particle selection, A. purpuratus was able to compensate for the differences in food quality of the experimental diets and ingesting particulate material containing 38% organic matter as a result of the selection process when fed at the higher food concentration. Absorption efficiency was lower following exposure to the high food concentration, suggesting that the experimental time of 72 h was not sufficient to acclimate the digestive response to a food supply significantly different from that of its habitat of origin. Phytoplankton form the principal nutritional source for this epibenthic species, and resuspended detritus, although occurring in large quantities, may only be of importance once digestive processes become acclimated to processing them.

Modiolus modiolus L. (horse mussel) reefs are a priority marine habitat of high conservation value that is currently listed as endangered and/or threatened across its European distribution. Population structure, density or shell morphology may influence the biodiversity of a reef, either directly or indirectly. Thus, such metrics are important considerations for successful conservation management of these biodiversity hotspots. Population structure, shell morphology and growth rates were examined in M. modiolus reefs across the UK range of the habitat to examine differences between key populations, including those near the Lleyn Peninsula in Wales (southern range), off Port Appin in Western Scotland (mid-range) and in Scapa Flow in the Orkney Isles, Scotland (northern range). Additionally, the influence of physical conditions (temperature and tidal flow) to growth rate and predicted maximum shell length for each population was examined. Growth rates were determined using acetate peels of sectioned shells. Lower juvenile abundance was observed in Scapa Flow. Small, narrow-shaped shells were found to be characteristic of North Lleyn mussels, and larger, globular-shaped shells were characteristic of mussels in Scapa Flow and off Port Appin. Mussels in Scapa Flow were slower growing, yet reached a longer asymptotic length (L∞) than mussels of Port Appin and North Lleyn. Growth curves from sites within this study were analysed with other published data. A trend of higher L∞ at higher latitudes and at lower flow rates was observed. Variations in growth and age are discussed in relation to flow regimes, connectivity to other reefs, density and latitude.

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.

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.

Thirteen cruises were made between mid-March and early June in 1954 off the coasts of southern Scotland and north-east England. It is likely that a Calanus patch was followed continuously during this period merely by observing the abundance of Calanus in and out the patch at very short time intervals (5–8 days between the mid-points of the cruises). Fig. 3 in Cushing & Tungate (1963) shows the distribution of Calanus copepoditestages during the period, which is the sort of picture expected if the same population were being sampled during the period. Application of the Joseph & Sendner (1958) equation suggested that the reduction of density due to diffusion was likely to be very low.