The feeding behaviour of stage I–III phyllosoma of the spiny lobsters Jasus edwardsii and Jasus verreauxi was recorded to determine the sequence of events and sensory mechanisms involved in the feeding process. All phyllosoma exhibited a characteristic tumbling behaviour prior to making contact with an individual Artemia and feeding behaviour was similar between the two species. Tactile contact with pereiopods 1 or 2 was necessary to initiate a prey capture response which involved spearing of Artemia, using the terminal dactyl present on these two pereiopods and then passing the prey forward to the mouth with the maxillipeds.

Scanning electron microscopy (SEM) of the pereiopods revealed two morphologically distinct receptors present on the distal segments. These receptors are suggested to have tactile and chemoreceptive roles.

Mytilus edulis attached more byssus threads to slate than to glass and more to glass than to p.t.f.e. in a given time period. This coincided with the order of polarity of the surfaces. On p.t.f.e., a non-polar plastic, the animals were most mobile, and were found to move off the surface in 3–5 days. Whilst on the polar surfaces, the animals clumped on glass, and remained relatively immobile on slate.

When a choice of surface for byssal attachment was provided, the largest number of pads was always attached to the more polar surface. The preference was as follows: slate/glass 2·80 : 1·00; slate/ 5·38 : 1·00; glass/wax 5·97 : 1·00. Although the preference for slate and glass over wax was numerically similar, there is a clear preference for slate over glass.

Planes minutus (L.) (Crustacea: Brachyura) swims well (forwards only) but has limited endurance; at 28°C crabs swam at the surface for 35–45 min before sinking. The legs of the neuston crab are flattened and rotated into the ‘advanced’ orientation of the legs to the cephalothorax, characteristic of swimming brachyurans. All legs are involved in swimming; pairs 1 and 2 mainly support the crab in the water column, pairs 3 and 4 provide forward propulsion too. In leg-pair 4, the plane of extension and flexion is close to the horizontal and the leg provides lift on the recovery stroke. Plumose hairs are present on the anterior borders of the legs, adding to the propulsive area. Stout spines line the anterior and posterior margins of the legs; they allow the crab to hang upside down from floating substrata, but are also used to hold food items. The chelae of Planes have cutting rather than crushing ‘teeth’. Crabs of the size studied (0·128−0·736 g wet wt) used oxygen (at 30°C) at about twice the rate when swimming (mean 1·014 ml O2 g wet wt−1 h1) as did resting crabs (mean rate 0·495 ml O2 g wet wt−1 h1). No oxygen debt is incurred during swimming. The mean crab density was 1·096 g ml−1 (SD 0·060). Neustonic crabs would not move more than 5 cm away from their floating substrata to catch food. They show a novel ‘revving up’ procedure in which leg pairs 1 to 3 beat while the animal is attached to the substratum by spines on the tips of leg-pair 4. This allows much of the locomotor apparatus to overcome inertia and reach working speed, before an attack is carried out. Crabs ate postlarval and juvenile fish, euphausids, isopods, sea skaters and squid. Gelatinous animals were gener-ally avoided, though salps were captured and the stomach contents eaten. Planes will take prey as big as itself and stores food for later consumption.

Although it has been stated (Thomson, 1927, p. 234; Elliott, 1953, p. 264) that the descending branches of the loop in dallinids, so far as is known, grow from the crura only, yet figures supporting this statement have not so far been published, not even by Beecher (1895) who described the very early stages of lophophore and loop in Dallinella (=Terebratalia) obsoleta (Dall). Tiny specimens of Macandrevia cranium dredged by R. V. ‘Sarsia’ have now made it possible for such figures to be published. It is a point of some importance as it is one of the characters given by Thomson (1927, p. 234) as distinguishing the Dallininae from the Mühlfeldtiinae (= Megerliinae Muir-Wood, 1955) and the Magellaniinae (= Terebratellinae, see Muir-Wood, 1955), for in the two latter groups the descending branches of the loop grow from both crura and septum to unite in the middle. At the time Thomson was writing, young growth stages of the loop of a member of the Laqueinae were not known. Since then, Konjoukova (1948, 1957) has studied the development of Laqueus californicus—which she placed in the Dallininae—and according to her the descending branches on reaching the septum join with it. She does not, however, figure any intermediate stages between absence of descending branches and complete ones. In 1941 Laqueinae was raised to family rank by Yabe and Hatai (see Muir-Wood, 1955, p. 93).

In previous papers (1932, 1933) the author showed that sea water taken from the English Channel contained about 10 mg./m.3 of copper, and obtained agreement between electro-deposition with subsequent colorimetric analysis and colorimetric analysis carried out on sea water concentrated to one-fifth of its volume. For extraction of the copper complex, carbon tetrachloride was found to be the most convenient solvent. The changes throughout the year have, however, only recently been determined. It is of interest to see that water from Station E1, surface, taken 23 March 1931, gave 10 mg./m.3 by direct colorimetry and 9·7 with electro-deposition, whereas the extraction method curves for 1948 and 1949, read off for the same date, showed respectively 9·4 and 11·4 mg./m.3.

Four individuals of the large scyphozoan jellyfish Stygiomedusa gigantea were observed in the northern Gulf of Mexico over 2005–2009 by industrial remotely operated vehicles as part of the SERPENT Project. One of these observations included the symbiotic bythitid fish Thalassobathia pelagica. Prior to these observations, neither S. gigantea nor T. pelagica had been observed in, or collected from the Gulf of Mexico. In order to summarize the available information on S. gigantea, we located 110 observations obtained over 110 years (1899–2009) representing 118 individual specimens of this species from around the world. The resulting dataset confirms that this species is cosmopolitan occurring with records from all oceans except the Arctic. While the depth-range of the four Gulf of Mexico specimens was bathypelagic, there appears to be a pattern of S. gigantea occurring in mesopelagic and epipelagic depth-zones at high latitudes, particularly in the Southern Ocean and mesopelagic and bathypelagic depths at mid- and low-latitudes. This pattern may be related to the meridional vertical distribution of temperature or perhaps avoidance of light levels that could degrade porphyrin pigments. There was no evidence that this species migrates vertically. Two of the individuals in the Gulf of Mexico appeared to be actively clinging to subsea structures and we speculate that this is a consequence of its normal mode of feeding, which may entail using its large oral lobes to hold on to, and trap prey.

Cetaceans of Morocco have been poorly studied to date, and only sporadic information comes from scientific cruises for this group. In an attempt to learn more on the occurrence, distribution and relative abundances of cetaceans in Morocco, a stranding database was reconstructed from various sources (stranding reports from state agencies and newspaper clippings). This inventory documented 205 cases of stranding between 1980 and 2009. Most of the strandings and most confirmed cases of interactions with human activity (fishing, for dolphins; collisions, for whales) were reported in the Strait of Gibraltar and adjacent areas from the Atlantic and the Mediterranean. Sixteen species were identified from the stranding database, of which seven species were the most abundant. These were striped dolphins, common dolphins, bottlenose dolphins, fin whales, sei whales, sperm whales and long-finned pilot whales. The fin and sei whales were present throughout the year and stranding of common and striped dolphins were minimal between September and December. The fin, sei and sperm whales seem to be present in Moroccan waters at birth and at different stages of their life cycle. Establishing an observation network of sufficient and sustainable density in Morocco is the most likely way to collect robust data for the calculation of credible population indicators for cetaceans. Monitoring will certainly improve through better collaboration among Moroccan institutions and a greater awareness in Moroccan civil society of environmental issues.

The Arabian Gulf is one of the most heavily impacted water bodies raising serious concerns about the conservation status of many marine species. A limited coastal range and near-shore distribution make Indian Ocean humpback dolphins particularly vulnerable to mortality and traumatic injuries from heavy maritime traffic and gill-netting practices. Prior to the present study, no research had focused on the ecology of this species in the Arabian Gulf, despite the potential for human impacts. The mark–recapture method of photo-identification, undertaken during 55 boat-based surveys conducted between 2014 and 2015, was used to assess the occurrence, abundance and use of habitat of this endangered species along the coast of the Emirate of Abu Dhabi (UAE). In all, 368 h and 6703 km of observation were carried out over a period of 5 months, and 54 encounters were made with humpback dolphins. The group size ranged from 1 to 24 individuals and group composition showed that 79% of the observed dolphins were adults. Abundance estimates were calculated and fitted with open population models. A review of all available data indicates that the studied population is the largest reported in the world with 701 (95% CI = 473–845) individuals. While their occurrence within Abu Dhabi near-shore waters is frequent, the survey area appears to be only a part of a much larger home range for this humpback dolphin population. The observation of multiple threats derived from anthropogenic activities increases our concerns regarding the conservation of this important dolphin population.

Cephalopods are common inhabitants of the deep ocean's mesopelagic zones worldwide, yet very little is known about their behaviour due to the inaccessibility of this environment. Recent studies suggest that, contrary to historical predictions, deep-sea cephalopods exhibit a wide array of visual behaviours. We used in situ footage from remotely operated vehicles, coupled with laboratory observations to assemble the first behavioural ethogram for the juvenile and subadult life stages of the mesopelagic squid, Chiroteuthis calyx. The number of behavioural components we described is comparable to or exceeds those recognized in ethograms of shallow-water teuthids. We used the ethogram to make a detailed behavioural comparison between the juvenile and subadult life stages, and found distinctly different patterns. Behavioural and morphological differences between the two life stages support the hypothesis that juvenile C. calyx mimic the abundant siphonophore Nanomia bijuga, in order to deter predation.

The genus Asconema, widely distributed in the North Atlantic and Arctic, was for some time considered to be monospecific. Its revision shows that it contains five species including the previously known A. setubalense, reinstated A. foliata and three new species (two of which are subdivided into three and four subspecies). The generic diagnosis is changed to encompass the specific characters of the new species.

Size at the onset of sexual maturity was determined in Munida rugosa based on allometric growth of chelipeds and abdomen, and on the proportion of ovigerous females. The variability of three different measurements of carapace length (CL) used previously for M. rugosa was also evaluated to minimize measurement error. Both sexes had symmetrical cheliped length and allometric cheliped growth over the size-range investigated, but males showed increased allometry beyond 22 mm CL. Females had greater positive allometry in abdomen width than males, but their size at maturity could not be precisely determined because sampled females were too large.

Temporal, spatial and diel variation in the distribution and abundance of organisms is an inherent property of ecological systems. The present study describes these variations and the composition of decapod larvae from the surface waters of St Paul's Rocks. The expeditions to the archipelago were carried out in April, August and November 2003, March 2004 and May 2005. Surface plankton samples were collected during the morning and dusk periods, inside the inlet and in increasing distances around the archipelago (~150, 700 and 1500 m). The identification resulted in 51 taxa. Seven species, six genera and larvae of the families Pandalidae and Portunidae were identified for the first time in the area. The mean larval density varied from zero to 150.2±69.6 individuals 100 m−3 in the waters surrounding the archipelago and from 1.7±3.0 to 12,827±15,073 individuals 100 m−3 inside the inlet. Significant differences on larval density were verified between months and period of the day, but not among the three sites around the archipelago. Cluster and non-metric multidimensional scaling analysis indicated that the decapod larvae community was divided into benthic and pelagic assemblages. Indicator species analysis (ISA) showed that six Brachyura taxa were good indicators for the inlet, while three sergestids were the main species from the waters around the archipelago. These results suggest that St Paul's Rocks can be divided into two habitats, based on larval composition, density and diversity values: the inlet and the waters surrounding the archipelago.

Off the coasts of the Eastern Aegean Island of Chios underwater observations were made on the labrid Crenilabrus (= Symphodus) ntelanocercus (Risso).

It was found that undisturbed observation could be made from 4 to 5 m away from the fish's territory, but if closer, then diver-orientated behaviour occurred. The fish might inspect the diver, or if alarmed, show fright reactions of different intensities. Conflict situations for the fish sometimes resulted in displacement chaffing. Pursuit caused the fish to show a series of escape reactions depending upon the intensity and persistence of the pursuit. Initially the fish showed avoidance reactions by fleeing or following set ‘escape routes’; further pursuit caused it to hide among the eel-grass, Posidonia; and finally aggregation and flight were resorted to.

Bivalve populations display fluctuating densities resulting in different interactions among them and with their environment. Using the edible cockle (Cerastoderma edule) as a model, we investigated two alternative hypotheses concerning the effect of density on individual infection intensity by trematode parasites. Considering that these parasites infect cockles through filtration activity, our first hypothesis was that high host density will have a dilution effect so that infection intensity decreases with host density. Conversely, high cockle density could attract other hosts used by these trematode parasites to complete their life cycle. A 17-year monthly survey of a cockle population in Arcachon Bay, France, showed a negative correlation between the cockle density and the abundance of parasite larvae in juvenile cockles with a significant threshold when adult cockle density reached 400 ind. m−2. This result was confirmed for the four dominating trematode parasites, independently considered. Additionally, a field experiment was performed during 9 months, with cockles maintained in enclosures with two densities (200 and 800 ind. m−2). Individual cockle mean infection was 1.5 times higher at low cockle density, mainly due to one dominant trematode species (Parvatrema minutum). In conclusion and confirming the first advanced hypothesis, for certain environments, negative consequences of bivalve intraspecific competition at high density can be mitigated by lower parasite pressure.

During April-June, 1967, tow-netting for bass eggs was carried out at four places on the Irish coast. Small numbers of bass eggs were obtained at two of these places, namely the Splaugh Rock, near Greenore Point, Co. Wexford and Youghal Harbour, Co. Cork. They were taken near the surface, in water of the salinity range 30–34.5%, and of surface temperature range 10.5–13.2°C.

The Irish material was larger than described by Bertolini (1933) from the Mediterranean, but smaller than described by Jackman (1954), who hatched eggs spawned in the Plymouth Laboratory Aquarium and described the larvae.

Introduction

Bass have spawned in the aquarium at Naples, and their eggs have been found in plankton in the Mediterranean (Raffaele, 1888; Bertolini, 1933). Bass have also spawned in the aquarium at Plymouth, and their eggs and the resulting young stages have been described by Jackman (1954).

Hitherto, however, the eggs of bass do not appear to have been found on the coasts of Britain or Ireland. The only young stages recorded were 14 post-larvae from 4 to 7.5 mm long, taken in the Eddystone area in the years 1925, 1926, 1931 and 1933, with dates of capture between 17 March and 4 June (Russell, 1935).

As part of a programme of research on the biology of bass in Irish waters, tow-netting was carried out in 1967 at the Splaugh Rock off the Wexford coast; at Dungarvan, Co. Waterford; at Youghal, Co. Cork; and at Baltimore, Co. Cork (Fig. 1). The Splaugh, Dungarvan and Youghal are places where bass ‘shoal’; that is, frequently gather in shoals to attack sand-eels, herring fry or sprats at the surface.

The nurse shark, Ginglymostoma cirratum, is considered an endangered species in Brazil and its capture by fisheries forbidden. Despite such legislation, nurse sharks continue to be caught as these laws are unenforced and fisheries are not monitored. The goal of the present study was to describe the population structure of nurse sharks caught off Ceará State, north-eastern Brazil, based on the following aspects: abundance and size, sex-ratio, fisheries incidence and seasonality of captures. Landings were monitored weekly during a two-year period. A total of 189 specimens were recorded. Total length (TL) varied between 73 and 274 cm. The male–female ratio did not differ significantly (1.19♀:1♂). TL of individuals landed as carcasses was estimated based on interdorsal length. The following equation was obtained for males and females: TL = 12.606ID + 14.24 (R2 = 0.9505). Most of the landed sharks were juveniles (86.2%). No seasonal pattern of abundance and TL variation was observed. Management of this fishery is required in order to prevent localized over-fishing of nurse sharks.

The stomach contents of a male sperm whale, Physeter macrocephalus, stranded on Forte dei Marmi beach (Italy, Ligurian Sea) were examined. Food items consisted exclusively of cephalopod hard parts: 233 upper and 291 lower beaks and one fish eye lens. The majority of the identified cephalopod beaks belonged to Histioteuthis bonnellii, but a few beaks of Galiteuthis armata and Octopoteuthis sp. were also found. A new beak size–cephalopod size regression was created for H. bonnellii with specimens caught in the study area. Reconstructed prey weight for the species was much higher when applying this new regression instead of Clarke's, highlighting the need for area- and species-specific regressions for dietary studies. Our analysis represents the second report on the stomach contents of sperm whales from the Mediterranean and the first available information for the Western basin.

Monthly sampling was conducted during one year in three zones along the estuarine gradient of Baía de Vitória, Brazil. Within each zone, unreplicated night trawls were done in deep subtidal flats located 130–210 m away and 2–3 m deeper than shallow ones. Twenty-one taxa represented 97.5% of the total mean fish abundance. The taxa Achirus lineatus (mean±SD: 2076±1269 10−4 m2), Eucinostomus spp. (694±807), Symphurus tessellatus (400±626), Sphoeroides testudineus (367±597) and Lutjanus synagris (323±445) dominated the deep assemblage (N=36) while Eucinostomus spp. (3649±4913), A. lineatus (1287±1569), S. testudineus (1208±1986), L. synagris (1101±927) and Sphoeroides greeleyi (569±1404) dominated the shallow assemblage (N=35). Taxa exclusive of one or the other depth showed extremely low abundance. The low-salinity shallow flats showed higher total abundance and taxa number than the high salinity deep locales but richness, diversity and equitability showed no significant differences among the six stations. The assemblage structure was significantly correlated to the depth structure but not to physico-chemical characteristics of the water. However, the spatial distribution of individual species varied greatly, from depth-dependent pattern to estuarine gradient-dependent pattern, with several intermediates. The community structure is singular in comparison to that of other tropical Brazilian estuaries studied to date. This is probably related to its geographical position in a transitional zone between the northern, tropical Brazilian oceanic domain and the southern, subtropical-temperate domain.

Off the coast of Cornwall from the Lizard Head to Padstow there has been, for many years, a small but locally important fishery for crawfish Palinurus elephas (Fabr.).

The fishermen had used pots and tangle nets up to the outbreak of the Second World War in 1939. From 1945 tangle nets had been little used and the fishery was pursued mainly by pot fishermen until the early 1960s when divers using self-contained under-water breathing apparatus began to collect crawfish. Tangle nets were re-introduced widely in the late 1960s.

São Tomé and Príncipe is an archipelago located in the Gulf of Guinea. This archipelago seems to be an important area for cetaceans, probably due to large concentrations of prey, as well as the existence of several small bays and shallow water that constitute preferred rest areas. In comparison to other areas of the world, little is known about cetacean communities in this archipelago. Boat-based surveys to record sightings of cetaceans were conducted between 2002 and 2005, which represents the first approach to study the occurrence of whales and dolphins in this tropical region. Sightings of humpback whales (Megaptera novaeangliae), bottlenose dolphins (Tursiops truncatus), pantropical spotted dolphins (Stenella attenuata), killer whales (Orcinus orca), sperm whales (Physeter macrocephalus) and pilot whales (Globicephala melas) were recorded. Cetaceans were found throughout a range of sea surface temperature between 24 and 29°C and a wide range of depths. Significant differences were found regarding the occurrence of some species. Humpback whales showed a preference for shallower waters between 20 and 100 m. Bottlenose dolphins occurred most commonly along the continental shelf (20 to 100 m) and pantropical spotted dolphins occurred in deep slope waters (>1000 m).