The morphology of the spines of the ophiuroid Ophiocomina nigra is described, with particular reference to the nervous system and the sensory and secretory structures of the epidermis. The nervous system is composed of two main spinal nerves, located at the centre of the spine, and their associated branches. There are three secretory cell-types described: (1) fibrillar secretory cells which produce long, javelin-shaped secretory pack-ages and, occurring exclusively in the basal two thirds of the spine, penetrate deeply with their basal regions lying close to the axial nerve running through the spine centre; (2) granular secretory cells, which also penetrate deep within the spine, contain secretory granules in the form of spherical dense vesicles (~1.3 μm in diameter); and (3) goblet secretory cells, filled with packages of loose amorphous material, are superficial in location and usually found associated with a type A ciliated sensory cell. The secretions of the fibrillar and granular secretory cells are thought to perform the functions of defence and feeding respectively. A number of different ciliated sensory cell-types have been identified. Apart from the situation with the goblet cells, no close association was found between secretory and sensory cells. It is suggested that the nervous, sensory and secretory cells act together to form a mucous secretion system with centralized, rather than local control. This system appears to operate when it is advantageous to produce secretion all over the body simultaneously once any portion is stimulated. Stimulation of sensory cells might result in axonal excitation of the spinal nerves and hence to the entire epineural nervous system.

The fourth Cephalopod International Advisory Council (CIAC) Symposium, on The Behaviour and Natural History of Cephalopods, was held at Vico Equense, Naples, Italy, from 5 to 11 June 1994. The meeting comprised lectures, poster sessions, keynote review lectures and a series of workshops. These were designed to examine the present status of six key subject areas and to identify possible ways forward for research. Summaries of the main conclusions from the workshops are given here in order to draw the attention of a wider audience to some of the main issues now being debated among students of cephalopod behaviour.

In November, 1933, a few medusæ were found in the plankton off Plymouth belonging to the genus Eucheilota. The only species of this genus so far recorded from northern European waters is Eucheilota maculata Hartlaub. The medusæ differed in several respects from this species, one constant difference being that the marginal vesicles never contained more than one concretion. In this respect they resembled E. duodecimalis A. Agassiz, but differed in having a much greater number of tentacles and marginal vesicles.

In October, 1934, the medusæ appeared again in considerable numbers and it was now possible to establish the constant features of the species which has apparently never been described before, except possibly for a drawing given by Hartlaub without a description (see below).

A number of mangrove systems with associated tidal flats occur in Coiba Island, located off the Pacific coast of Panama, two of which were selected for the present study: Santa Cruz and El Gambute. Three transects were selected on each tidal flat and three sampling sites were arranged along each one: lower, middle and upper intertidal. During 1997, two samplings were carried out at each site, in February and November. The results of the faunistic studies revealed the presence of ten species of Orbiniidae, two of which belonged to the genus Leodamas. Leodamas minutus sp. nov. is easily distinguished from all other species within the genus by having a cylindrical thorax composed of 13 chaetigers, the first three chaetigers without notopodial lobes, thoracic neuropodia without postchaetal process, and abdominal neuropodia, short, bilobed and with protruding acicula. Leodamas platythoracicus sp. nov. can be recognized by its thorax, distinctly flattened in the posterior half and consisting of about 19 chaetigers, by its thoracic neuropodia, with many spines arranged in one or two rows and few, if any, slender capillaries, and by the shape of its abdominal neuropodia, which are long and subterminally notched and bear a distal process.

Studies of sea turtle epibiosis have focused on the diversity and ecology of facultative commensalisms and less attention has been given to parasitic associations, in which the epibiont species derives nutrients from the tissue of the host turtle. We present the first description and quantitative survey of the parasitic isopods Excorallana costata, Excorallana bicornis and Excorallana oculata on loggerhead (N = 79) and hawksbill turtles (N = 23), and E. costata on olive ridley turtles (N = 9), nesting on Praia do Forte, Bahia, Brazil during the 2009–2010 season. Excorallana costata was the most common isopod species (N = 651), followed by E. bicornis (N = 77) and E. oculata (N = 20). Patterns include: (1) E. costata exhibited a higher frequency and intensity of parasitism than E. bicornis and E. oculata and (2) loggerheads hosted parasitic isopods at a higher frequency and intensity than hawksbills and olive ridleys. We also detected temporal shifts in the occurrence and intensity of parasitism across the nesting season, which strongly suggests that turtles were parasitized by all three isopod species during their internesting periods. Because parasitic isopods were observed only rarely prior to the 2009–2010 turtle-nesting season and have continued to be common in subsequent seasons, it is important to gain a better understanding of the basic biology of these interactions, the reasons for their recent emergence, and the potential biological impacts on turtle, as well as isopod, populations.

Euphausiids are an important component of the northern North Atlantic ecosystem and several species are found in the Irminger Sea. However, data on euphausiids in this region are few, particularly for Thysanopoda acutifrons, Thysanoessa inermis and Nematobranchion boöpis. In this paper, we present the first data since the 1930s on the seasonal distribution and population dynamics of these species from net haul data collected in the Irminger Sea during winter, spring and summer 2001–2002. Thysanoessa inermis was the most numerically abundant (0.63–26.62 ind. 1000 m−3) of the three species in the region and comprised a biomass of 3.92–41.74 mg 1000 m−3. The species was largely found in the upper regions of the water column (0–400 m) and was distributed in the more on-shelf/shelf-break regions around East Greenland and Iceland. Growth rates were around 0.03 mm d−1for T. inermis and there was some evidence that either the timing of spawning was delayed, or larval development was prolonged in the region. Thysanopoda acutifrons was predominantly distributed below 400 m in more oceanic regions and had a low abundance (1.23–1.64 ind. 1000 m−3) throughout the Irminger Sea. However, the species comprised a relatively high proportion of biomass (19.39–31.33 mg 1000 m−3) due to its large body size. Our data showed that the species had low rates of growth (0.04 mm d−1) and development throughout the year, and that the reproductive season occurred during the overwintering period (November/December) once individuals had reached two years of age. Nematobranchion boöpis mainly occurred below 400 m at low abundance (0.06–0.18 ind.1000 m−3) levels throughout the region. The species was largely found where Atlantic waters prevailed in the Irminger Current and its growth rates were variable (0.02–0.06 mm d−1). Nematobranchion boöpis was a year-round spawner and the species had fairly rapid rates of post-larval development, with the newly spawned 0-group reaching sexual maturity within the first 6 months. Data presented in this paper provide useful baselines for understanding the possible impacts of long-term, broad-scale environmental change on the ecology of euphausiid communities in the Irminger Sea.

A fixed bottom net was used to study the relationship between the horizontal and vertical density distribution of polychaete and cirripede larvae over an inshore rock platform.

Strong horizontal density distributions were obtained close to the bottom in many species from both groups, while the vertical samples showed larvae to be distributed towards the bottom both during the day and at night. It is suggested that the concentration of larvae within the slow-moving bottom water was responsible for the observed limited lateral larval dispersal.

The results are discussed in relation to their bearing upon a number of problems within the field of meroplanktonic ecology.

This work is an interpretation of a chronological data set on abundances of estuarine soft substrate invertebrates using an ecological approach. The data were collected in the framework of the European programme COST 647 (Coopération Scientifique et Technique) on coastal benthic ecology which terminated in 1992. Species numbers and selected environmental factors were recorded at two stations in the Baie de Somme (France) from 1981 to 1992. Inter-annual and seasonal variations in benthos numbers were analysed using a plotting procedure based on a non-probabilistic approach, proposed by Andrews in 1972. Ecological groups of species were identified and succession in time described, coinciding with alterations in the landings of cockles Cerastoderma edule. The chronological data set was processed through the application of the cumulated function, giving directly intensity and duration of any changes in relation to the climate and water quality, especially potential eutrophication manifestations.

Removal of egg-tending males in a monogamous goby, Amblygobius phalaena, was performed on coral reefs of Okinawa, Japan. All five removal experiments led to shifts of parental care to the paired females, and two of the females continued egg care until just before the eggs hatched. Evolution of the shift of parental care to a non-caregiving parent in this species may be facilitated by the spatial closeness between mates after spawning and no necessity of special structures and organs for guarding care.

A simple data acquisition and control system has been developed for the measurement of the spectral emission from bioluminescent animals. A programmable calculator system is used to control a monochromator and to measure, record and graphically display the results. Results from calibration sources and three animals are described with comments on the success of the technique.

The process of asexual reproduction, described below, is, as far as the writer is aware, unique among hydroids. In all known species of hydroids in which an asexual bud formation has been described (e.g. in Hydra), the mouth and oral tentacles develop at the free end of the bud and the proximal or fixed end becomes the base. The sequence of development of medusa buds is essentially similar. This method applies also to budding in other Coelenterates. In the present instance the bud instead of growing out “head first,” came off “tail first,” came off “tail first” –the proximal end developing mouth and oral tentacles and the free end becoming the stalk. I can find no recoid of such a method having been described before.

The morphology of the setae, on the mouthparts and the cirri of 33 barnacle species, was investigated by scanning electron microscopy. The species examined were selected from a range of pedunculate and balanomorph families living in a variety of habitats from the littoral zone to deep-sea vents. It was found that the setae could be divided into five groups: simple, denticulate, setulate, plumo-denticulate and aesthetascs. The categories were subdivided resulting in 43 setal types being recognized. Balanomorph cirripedes were found to have a greater variety of setae than pedunculates. Setulate setae on the cirri, and specialized setae on the mandibular palps and the first maxillae tended to be associated with the development of the balanomorph form. Setal type was correlated with taxonomy, whether based on shell structure and soft body morphology or DNA analysis, but with some anomalies which deserve further investigation. The problems of reconciling the proposed cirripede setal categories with those described in the Decapoda are discussed.

The northern Galician rias provide important economic and social services from fisheries, shellfish harvesting and recreational activities. Consequently, these rias have been included in the Nature 2000 Network as a Special Conservation Zone. The aims of this study were to describe the meiofauna spatial structure in terms of diversity and abundance of major taxa, as well as its relationship with the environmental characteristics in the Ria de Foz nature reserve. For this aim, environmental gradients and distribution patterns of intertidal meiobenthic communities at the Ria de Foz nature reserve were studied using multivariate methods. Ria de Foz showed to be a complex transitional habitat with significant changes in its environment along the estuarine gradient. An abundant and rich meiofauna community was reported at Ria de Foz. A total of 21 higher taxa of meiofauna were found. The most common taxa were nematodes, copepods, ostracods and turbellarians. Three clear different meiobenthic communities were defined. These three communities showed a clear spatial distribution pattern along the estuarine gradient. Moreover, a high degree of similarity between distribution patterns of meiobenthic communities and previously studied macrobenthic communities was found. Regarding the role of environmental factors shaping meiobenthic community distribution patterns distance to the river mouth was the environmental variable that best explained meiobenthic community structure and distribution. Therefore, changes on hydrodynamics that affect environmental factors related to the estuarine gradient will change the distribution pattern and diversity of benthic communities. This work provides the first information about meiobenthos diversity and structure in the Ria de Foz nature reserve and should be useful for future management and conservation plans on this and other similar protected areas.

The occurrence of a population of Ophelia bicornis has been recorded at a site which may be the most northerly for the species, and the only one within the United Kingdom. The irregular and patchy distribution of the population is described and reviewed in relation to other recorded occurrences of the polychaete.

Big-bellied seahorses, Hippocampus abdominalis (Chordata: Syngnathidae), feed predominantly on swarming mysids in southern Tasmania. We tested the possibility that kairomones mediate this predator/prey interaction. ‘Fish water’ was prepared by holding one seahorse in 4 l of seawater for 1 h and using this water within 1 h to test for presence of kairomones. One ml of this water pipetted into a tank containing five mysids, Paramesopodopsis rufa (Arthropoda: Mysidacea), induced a significantly increased number of tailflips (mysid escape response) compared with control seawater. The same effect was seen whether seahorses were fed or starved immediately before the experiment. This effect was not seen when realistic concentrations of excretory products, either ammonium hydroxide or urea, were used instead of fish water. When seahorses were kept in visual contact with mysid prey, but unable to capture them, subsequent testing of the ‘fish water’ in the same way as above did not produce a significant increase of tailflipping in mysids. Thus it appears that, when attacking, seahorses can suppress release of kairomones in order to remain chemically inconspicuous to their prey. This is the first demonstration of this phenomenon. When mysids in a cohesive swarm (65 or 100 individuals) were exposed to ‘fish water’, no significant anti-predator response i.e. decrease in swarm volume, could be detected. We interpret these results to indicate the greater vulnerability of mysids when not in social groupings (swarm or school) and the higher likelihood of an energetic response (particularly tailflipping) to a threat.

The amphipod Ericthonius didymus Krapp-Schickel, 2013 is reported for the first time outside its type locality in European waters, from the French Atlantic coast and from the Azores, Portugal. In particular, a large population was recorded in Arcachon, France. Molecular analyses were made to confirm the validity of three closely related Ericthonius species: E. didymus, E. convexus and E. pugnax. An identification key is provided, distinguishing Ericthonius species into three groups, based on the presence or absence of stridulating ridges on coxa 2 and posterodistal lobe on basis of male pereopod 5.

Ocean acidification (OA) is caused by increasing atmospheric concentrations of carbon dioxide, which dissolves in seawater to produce carbonic acid. This carbonic acid reduces the availability of dissolved aragonite needed for production of some invertebrate exoskeletons with potentially severe consequences for marine calcifier populations. There is a lack of public information on OA with less than 1% of press coverage on OA compared with climate change; OA is not included in UK GCSE and A Level specifications and textbooks; environmental campaigners are much less active in campaigning about OA compared with climate change. As a result of the lack of public awareness OA is rarely discussed in the UK Parliament. Much more public education about OA is needed so that people can respond to the urgent need for technological and lifestyle changes needed to massively reduce carbon dioxide emissions.

The susceptibility of marine bacterial communities to copper pyrithione (CuPT2), zinc pyrithione (ZnPT2) and their degradation product is described and toxicities of these relatively new antifouling biocides compared with those of their harmful organotin (OT) predecessors, tributyltin (TBT) and triphenyltin (TPT). These biocides were added to agar at concentrations of 0, 0.01, 0.1, 1 and 10 mg l−1 and coastal seawater including indigenous bacteria added to each batch of agar solution. The number of bacterial colony forming units (CFU) was measured after 7 days culture. Relative CFU (as a percentage of control) was more than 80% at a concentration of 0.01 mg l−1 of each compound, except for TBT. Relative CFU decreased as a function of dose of each biocide, although concentration-dependent changes in rate of CFU were relatively low during exposure to degradation products of CuPT2 and ZnPT2, pyridine N-oxide (PO) and pyridine-2-sulphonic acid (PSA). Based on comparisons of EC50, TBT was the most bacterio-toxic of the tested compounds (0.2 mg l−1), marginally more so than CuPT2 (0.3 mg l−1). Interestingly, EC50 values of degradation products of CuPT2 and ZnPT2, 2-mercaptopyridine N-oxide (HPT) and 2,2′-dithio-bispyridine N-oxide (PT2) were 0.8 and 0.5 mg l−1, respectively, lower than that of the parent chemical, ZnPT2 (1.4 mg l−1). The EC50 of PT2 was also lower than that of TPT (0.7 mg l−1), implying higher toxicity. Given the overlapping toxicity ranges, these results suggest that marine bacterial communities experience comparably high susceptibility to metal PTs and OTs during their life history.

Crab-baited traps, with a 5-mm diameter opening, were deployed 90 mm off the seabed monthly at Lobster Bay, Hong Kong, for one year between 1998 and 1999. Visitors drawn to the traps were mainly species of Ceradocus (Gammaridea: Melitidae), Tisbe (Harpacticoida: Tisbidae) and Nebalia (Leptostraca: Nebaliacea). Apart from Ceradocus sp., all were scavengers with catches using baited traps significantly exceeding unbaited controls. Ceradocus sp. was apparently drawn to traps for refuge. The trapped scavenger community composition changed with deployment duration in the presence of bait. Nebalia sp., Neanthes cricognatha (Polychaeta: Nereidae) and Lepedepecreum sp. (Gammaridea: Lysianassoidea) were identified mostly two/three-days post-deployment, exhibiting a potential preference for rotten organic matter. Seasonal catches were also identified for all three visitors with maxima between October 1998 and April 1999. Such seasonal patterns might be related to either turbulence destabilizing the substratum during this period or life cycle patterns in the study area.

The English fisheries which were investigated with the Plankton Indicator in 1931,1932, and 1933 were divided into three areas, i.e., those off Shields, the Humber mouth and the East Anglian coast (this last fishery was also sampled in 1930). All the samples in the Shields area lie between 56° 00 N. Lat. and 54° 20 N. Lat., whilst the majority (80%) lie in the area between 54° 45 N. Lat., and 55° 30 N. Lat. and a line parallel to and some 40 miles from the coast. This is an area of some 1600 square miles. In the Southern Bight Lat. 53° 00 N. was taken as a division between the Humber and the East Anglian areas. The distribution of all the samples is shown in Figs. 1 to 4. With the exception of the samples obtained by the Ministry of Fisheries research ship Onaway in June, 1931, and four samples obtained by H.M.S. Chenoell in September, 1933, all those in the Shields area have been collected by individual drifters engaged in the fishery. The Humber and East Anglian samples were obtained from both drifters and gunboats of the Fishery Protection and Mine Sweeping Flotilla alongside drifters fishing. The manner of collecting these samples has been described in Part I (p. 153).