We estimated the prevalence of the bopyrid Pseudione galacanthae parasitizing the population of the squat lobster Munida gregaria in San Jorge Gulf and analysed some aspects concerning the effect of the parasite on host reproductive potential. The relationship between the development stages of the parasite and the host size was also analysed. The squat lobsters were caught as by-catch in the coastal area of the gulf from vessels operating in the fisheries of hake Merluccius hubbsi, southern king crab Lithodes santolla and Argentine red shrimp Pleoticus muelleri. The samples were collected between October 1997 and June 2009. In the laboratory, squat lobsters were sexed and the length of their carapace was measured. In males, the length of the right cheliped was recorded and gonadal development was examined. In females, the size and number of carried eggs were determined and the length of the pleopods III, IV and V were measured. All squat lobsters parasitized exhibit a gross bulge in the right side of carapace. Prevalence ranged between 0 and 1.43% (N = 21,519). No significant differences in prevalence were found for sexes, depths and seasons. The prevalence was higher for the size interval 7–10 mm CL (0.79%) than for the rest of the intervals. Parasitism had no effect on the secondary sex characters. Parasitized males displayed gonad development. There was no difference in prevalence between ovigerous and non-ovigerous squat-lobster females. Parasitized females had smaller eggs than non-parasitized ones, but their fecundity was similar. The linear relationship between the parasite and host sizes and the presence of larvae and immature stages of P. galacanthae in small-sized squat lobsters suggest that the host is infected early in its development. The low prevalence could be related to oceanographic conditions which favour larval dispersal of the parasite and host. The infestation by P. galacanthae has little impact on the M. gregaria population, mostly due to the low prevalences of infestation and the minor impact in reproductive function.

Many preys retreat into a refuge as a response to the presence of a predator, a behavioural strategy which guarantees safety but is also costly due to a trade-off between hiding time and time spent in other essential activities. The balance between costs and benefits of hiding, which are influenced by different factors, determine the hiding duration. In a field experiment, the anti-predator behaviour of the mud crab Austrohelice crassa was studied to assess the effects of two factors, body size and neighbour density, on the time spent hiding in burrows following a predator threat. Hiding times, body size (estimated from burrow diameter) and neighbour density (number of other burrows within a 30 cm radius) were measured for 158 individual crabs during a snorkelling survey. Regression analyses showed that hiding time of individual crabs significantly increased with increasing body size, and decreased with increasing neighbour density. These trends are the result of three main selective pressures: size-biased predation risk, dilution of predation in dense clusters of burrows, and more intense competition in dense clusters. Variation among individual crabs probably reflects differences in the balance between costs and benefits for crabs differing in body size and neighbour density.

Cadmium, chromium, copper, nickel, lead and zinc concentrations in the bivalve mollusc Macoma balthica and the polychaete annelids Hediste diversicolor and Arenicola marina were measured, during winter and summer, at sites throughout the Severn Estuary and Bristol Channel. The mean concentration of each metal in A. marina was greater in the lower Severn Estuary than in the far less contaminated outer Bristol Channel and the concentration of a given metal, e.g. Cr, in a species occasionally peaked at a site, reflecting local metal contamination. The concentrations of each metal in each of these biomonitor species almost invariably differed significantly among sites and often seasons and there were sometimes interactions between site and season. This indicates that the various factors that determine the concentration of a metal in a species operate in a complex manner and that their individual effects can vary among sites and/or seasons. The rank order of each metal concentration in each species at a site within the estuary frequently did not match the sequence for the concentration of that metal measured in the sediment at that site at the same time. This lack of correspondence is likely to be due, at least in part, to one or both of the following: (1) variations in the bioavailability of certain metals among sites due to differences in such features as the metal-binding properties of the sediments; (2) the effects of the constant transport and redistribution of the sediments and thus also of their associated trace metals by the very strong tidal action that characterizes the Severn Estuary. This would mean that single time measurements do not accurately reflect the overall trace metal environment to which the biomonitor organism had been exposed in the weeks/months prior to sampling. Marked differences in the concentrations of certain metals, e.g. Cu and Zn, in co-occurring biomarker species could frequently be related to differences between the ability of these species to regulate certain metals. Non-metric multi-dimensional scaling ordination and associated tests emphasize that the relationships between the concentrations of the various metals differed markedly among species and between sites and seasons in individual species and elucidated which metals contributed most to those differences. If the proposed scheme for harnessing tidal power in the Severn Estuary proceeds, the data in this paper provide a baseline for assessing the impact of such major changes on the bioavailability of trace metals in this estuary. This information will also be invaluable for predicting the changes likely to occur in other estuaries that become subjected to major structural changes.

The taxonomy of the genus Tethya from Brazil is revised. Five species are described, four of which are new to science: Tethya maza, T. beatrizae sp. nov., T. nicoleae sp. nov., T. parvula sp. nov., and T. solangeae sp. nov. Five earlier records of Tethya from Brazil (T. aurantium, T. diploderma, T. maza, T. japonica and T. seychellensis) are re-evaluated and only T. maza is confirmed. The other previous records of Tethya from Brazil, viz., Tethya brasiliana, T. cyanae, T. ignis and T. rubra, have been recently described in detail using scanning electron microscopy and are also considered valid. An amendment to the nomenclature of micrasters is made, recognizing at least two different morphologies of each type of micraster (strongylasters types 1 and 2, tylasters types 1 and 2, and oxyasters types 1, 2 and 3). A neotype was designated for T. maza. With four new species described here and four previous records considered invalid the known diversity of Tethya in Brazil still remains nine species. However, its rate of endemism has increased from 44% to 89%.

The oilfish, Ruvettus pretiosus, is an incidental by-catch of the drifting surface longlines targeting swordfish and Thunnidae in the Mediterranean and elsewhere. Despite its global distribution and frequent occurrence in the catch of many fishing gears, little is known about its biology. In this study we examined the dietary preferences and reproductive biology of this species from specimens caught in the eastern Mediterranean. The most numerous and frequently occurring prey items were benthopelagic fish, followed by cephalopods. The sex-ratio was highly skewed in favour of females (1:8.4), while histological examination of the collected ovaries displayed six developmental stages (perinucleolar, early and late lipid stage; early, middle and late vitellogenesis). Oocyte diameter ranged from 23–69 μm at the perinucleolar stage to 224–366 μm at the late vitellogenesis stage. Spawning is expected to occur during mid and late summer; however there were no individuals available from this period. The findings are discussed in relation to the ecology of the species.

The biology, growth and reproduction of the axillary seabream, Pagellus acarne, was studied based on data obtained from the catches of the Andalusia commercial fleet operating off the coasts of southern Spain from October 2003 to September 2004. The axillary seabream had a very wide depth distribution, appearing from the surface down to 500 m depth. The length–weight relationship was given by TW = 0.0048 TL3.3207 (R2 = 0.98) (TW = total weight; TL = total length) for all fish from the Gulf of Cadiz and TW = 0.0093 TL3.1132 (R2 = 0.94) for all fish from the Alboran Sea. The proportion of females to males increases as length increases in both populations and the species is characterized by protandric hermaphroditism. Spawning males were present almost throughout the year although higher percentages were observed in spring and early summer. In females, the spawning period occurred mainly in spring. In both areas, the mean size at first maturity for males was smaller than for females. The mean lengths at first maturity were 18.04 cm for males and 21.7 cm for females from the Gulf of Cadiz, and 17.7 cm and 20.1 cm for males and females from the Alboran Sea, respectively. The average total fecundity was estimated at 290,070 and 173,509 oocytes for Atlantic and Mediterranean individuals, respectively. The parameters of the von Bertalanffy growth model were estimated by age readings of the 247 sagitta collected. Two rings, one opaque and one hyaline, were laid down each year on the otoliths. The opaque zone was formed during spring and summer and the hyaline one during the remaining months of the year. The relationship between otolith radius and total length of the fish was described by the equation: TL = 27.7 OR – 1.8 (r = 0.96) (where OR = otolith radius). The parameters of the fitted Von Bertalanffy growth equation were L∞ = 31.65 cm, k = 0.21 yr−1 in the Gulf of Cadiz and L∞ = 32.14 cm, k = 0.17 yr−1 in the Alboran Sea.

In this study, fecundity of Munida gregaria in northern Patagonia was analysed in relation to size and compared with other studies in different sites along its latitudinal distribution. Also, morphological changes in embryos reared in the laboratory, and the chronology of its appearance were observed. Fecundity (total number of eggs in a clutch) was strongly correlated to size (carapace length in mm) (R = 0.638) and the regression equation fitted by least squares was Log(F) = −1.37 + 3.85 · log(CL). Size specific fecundity was higher than in southern locations along Patagonia. Recently extruded eggs are smaller than in southern Patagonia measuring an average of 530 μm in diameter and 0.043 mm3 in volume. When ready to hatch, those measures increased by 30% and 50% respectively. Complete embryonic development lasted an average of 27.9 days at fixed temperature of 11°C. Five development stages were defined based on morphological changes: (1) from fertilization to the appearance of embryonic primordium (2–3.5 days); (2) embryonic tissues occupying less than half of the egg perimeter in lateral view (7–10 days); (3) embryonic tissues without pigments and occupying more than half of the egg perimeter in lateral view (5–8 days); (4) embryos with reddish eye pigments and chromatophores (4–6 days); and (5) ocular globe completely pigmented (3–4 days).

Assessing and monitoring the environmental impact off Mar del Plata (38°S 57°W) led to the need to identify the cirratulid polychaetes. Cirratulids are indicators of moderately impacted areas or early indicators of organic contamination. Some subtidal sand patches affected by sewage discharge have high abundances of a new, rare and difficult to place species, such as Caulleriella trispina sp. nov. This species is characterized by having characters of three bitentaculate cirratulid genera, including three kinds of spines: unidentate, sub-bidentate and bidentate. The genera and their taxonomic characters are discussed as well as the need for monitoring and environmental assessments for correct identification. A key to the known species from the warm-temperate region of Argentine Cirratulidae is given.

The toxicity of produced formation water (PFW) originating from four natural gas production platforms located in the Adriatic Sea (Italy), and of seawater samples collected near these installations is assessed by means of bioassays with Brachionus plicatilis, with the brine shrimp Artemia franciscana and with Paracentrotus lividus. The toxicological response of these specimens was evaluated in order to identify the most sensitive one, in the consumer compartment, and to design a bioassay battery specific for samples collected in the surroundings of a gas platform. Larval mortality of rotifers, larval immobilization of crustaceans, fertilization success/failure (sperm cell test) and larval (pluteus) development success/failure (embryo toxicity test) of sea urchins were taken as ecotoxicological endpoints. The PFW sampled on two platforms resulted toxic, while no toxicity was recorded in seawater samples collected in the vicinity of the platforms, even in coincidence with the PFW discharge operations. The species and bioassays employed have shown different responses to PFW: P. lividus turned out to be more sensitive than A. franciscana and B. plicatilis. In particular, the embryo toxicity test showed a higher toxicity than the sperm cell test.

Phenotypic variation on shell size and shape of Olivancillaria carcellesi from four representative localities is confirmed using geometric morphometric techniques. This species lives along the entire range of the genus in subtidal soft bottoms from Rio de Janeiro (Brazil) to Punta Pardelas (Chubut, Argentina). Thickness of columellar callus, length and width are the main shell differences from specimens collected at several intermediate localities: Cassino (Brazil), La Paloma (Uruguay) and Mar del Plata (Argentina). All forms showed significant differences in shell size except O. carcellesi from La Paloma compared with those from Mar del Plata. The group with larger specimens was from Cassino. Olivancillaria carcellesi from Punta Pardelas, the southernmost population, was the smaller sized group and showed allometry between size and shape and this is responsible for their relatively higher spires. The possible ecological implications of the observed pattern are discussed. It is confirmed that O. carcellesi although variable, is a clearly defined species.

The aim of this work is to study the variation of the global chemical composition of six fish species (Lithognathus mormyrus, Mullus barbatus, Mullus surmuletus, Pagellus erythrinus, Pagrus caeruleostictus and Dentex maroccanus) caught by the trawl of the Gulf of Gabès (Mediterranean Sea). The variations of the chemical contents of the fish as a function of size, sex, organs and parts of the muscle were examined between December 2005 and May 2006. ANOVA indicated that the global chemical composition was significantly affected by two factors: species and body locations (parts of the muscle). The correlation matrix established between the chemical contents showed two highly significant correlations (fat–moisture and protein–ash). The discriminant analysis allowed the distribution in the space of fish species into five groups according to their moisture, proteins, fat and ash contents. The analysis of the fat content in the parts of the fish body revealed the presence of a concentration gradient.

Cirratulus dollfusi Fauvel, 1928 is re-described from the material from the Sea of Marmara. The specimens collected from the Sea of Marmara were compared to the holotype of the species. The species is a multitentaculate and multibranchiate cirratulid; it differs from all other known cirratulid genera in its type of chaetae and the way the multiple branchial filaments arise from the notopodia. Chaetae are of two types: numerous long, fine capillaries in both rami throughout, also 2–4 shorter, wider, finely tapering spines in noto- and neuropodia. There are no slightly flattened sigmoid spines, typical of most Cirratulus species. Very short, slender grooved tentacles arise in a small circular group on either side of chaetiger 1. Branchial filaments are multiple; they arise as 1–2 filaments from each of 4–8 raised notopodial lobes on parapodia of anterior and middle segments, with lobes fading out and fewer (holotype) or no branchiae posteriorly (our material). No other cirratulid genera appear to have straight, tapering spines plus so many fine capillaries. We propose Fauvelicirratulus gen. nov. for this species. The species seems most closely related to Cirratulus hedgpethi Hartman, 1951, from the northern Gulf of Mexico, still only known from the incomplete original description. Features of some cirratulid genera are compared and the use of multiple branchiae as a generic character is discussed.

Age and growth of adult gilthead seabream, Sparus aurata were determined from 332 specimens (total N = 476), collected from purse-seiners, in the south-eastern Aegean Sea from November 2006 to January 2007. The fork length and body wet weight ranged from 26.5 to 51.5 cm (mean: 36.6 ± 0.18) and from 375 to 2600 g (mean: 1009.2 ± 14.16), respectively. Age groups were varied between 2 and 7. Growth parameters were estimated as L∞ = 64.97 ± 12.93 cm, K = 0.14 ± 0.07 year−1, t0 = −2.47 ± 1.09 year−1, and index of phi-prime was Φ′ = 2.772 ± 0.51. The length–weight relationship equation of all fish was calculated as W = 0.0515 × L2.737 (r2 = 0.95). The mean condition factor was estimated as 2.058. Mortalities (M, F and Z) and exploitation rate (E) of gilthead seabream from the Aegean Sea were 0.34 year−1, 0.77 year−1, 1.11 year−1and 0.69 year−1, respectively. The result of E indicated that the population was overexploited.

The symbiotic association between the acoel flatworm Symsagittifera roscoffensis and the prasinophyte microalgae Tetraselmis convolutae was studied regarding its photophysiology and photobehaviour. The photoacclimation status and the photophysiological responses to high light of the algal endosymbiont were studied non-destructively on individual S. roscoffensis using pulse amplitude modulated fluorometry. Specimens collected in an intertidal sandy shore were characterized regarding the maximum quantum yield of photosystem II (PSII), Fv/Fm, and the light response of photosynthetic activity, by constructing rapid light-response curves of the relative electron transport rate of PSII, rETR. The studied population could be considered as high light-acclimated when compared with other intertidal photosynthetic organisms (e.g. macroalgae), with the light-saturation parameter Ek averaging 250 μmol m−2 s−1. Light stress experiments showed S. roscoffensis to be able to withstand the exposure to high light without displaying signs of photoinhibition, suggesting the operation of efficient physiological photoprotective processes. The photobehaviour of S. roscoffensis was studied by characterizing the distribution of the flatworms under a light gradient, using a custom-made photoaccumulation chamber. The results showed a photoaccumulation pattern evidencing a clear avoidance of extreme low or high light levels, and with maximum photoaccumulation values being found for a range of irradiances (150–400 μmol m−2 s−1) that generally coincided with the optima for photosynthetic activity. This matching between the optimum light levels for photosynthetic activity and photoaccumulation suggested that S. roscoffensis may use vertical migration as a form of behavioural photoprotection. This behavioural response may be used to rapidly and flexibly control light exposure, avoiding photodamage to the endosymbiont photosynthetic apparatus by direct exposure to sunlight.

In altricial mammals, mothers' care and attendance are essential for young to acquire survival skills. Despite the crucial importance of this early period for pup survival, not much is known about mother–pup behaviour and time allocation in the wild. To improve our understanding of the critical period of the sea otter development, a total of 240 30-minute focal follows of females with pups of different ages were conducted in four 6-hour-periods (dawn, day, dusk and night) from 4 June to 12 August 2008. Generalized linear models were used to investigate the impact of age, weather, tide and time of day on otters' behaviour. Pups significantly decreased resting behaviour and increased feeding, travelling, interacting and grooming behaviour with increasing age. Females with large pups fed and interacted significantly more, and travelled and groomed the pup less than females with small pups. Foggy conditions were associated with less resting on the water and increased travelling by pups. Tide did not appear to have an effect on sea otter behaviour. Grooming by pups occurred mainly during dawn in medium sized pups whereas large pups groomed themselves mostly during the day and night. Variations due to times of day tended to be apparent only in larger, i.e. older pups. Females and large pups were more active during the day. Mothers of smaller pups spent most of their active time travelling whereas females with large pups were mostly feeding. This study showed how sea otter females with pups adapted their behaviours as their pups grew and matured during the first months of life.

A new species of Chloeia (Annelida: Amphinomidae) is described from deep water (750–1045 m) off southern Brazil. Chloeia kudenovi sp. nov. differ from previously described species by the extremely elongated neuropodial cirri of the second chaetiger, number and position of noto- and neuroaciculae and lack of body pigmentation. This study provides additional data on the morphological diversity of the genus.

Very little is known about the life history of Robsonella fontaniana. In particular, there are no descriptions of the early life stages that enable correct identification of samples taken from the wild. In this work, eggs and hatchlings are described from egg clutches obtained in the field with brooding females and incubated until hatching. Individual eggs exhibited marked differences in stages of embryonic development within egg clutches or even within a single egg string. For one clutch collected at early stages of embryonic development, embryogenesis took 91 days at 11.5 °C and for a second clutch at intermediate developmental stages it took 68 days at 11 °C and 39 days at 14 °C. For the later clutch the hatching period lasts 25 days at 14 °C. The eggs and paralarvae were small, with an egg length of 3.9–5.2 mm, a dorsal mantle length of 2–3 mm and a total paralarvae length of 3.4–6.0 mm. Chromatophore shape and distribution presented a very distinctive pattern. Characteristics of the eggs, egg strings and paralarvae make it possible to distinguish the early stages of R. fontaniana from those of other octopodid species found off the Atlantic coast of Patagonia.

Oceanic juvenile loggerhead sea turtles, Caretta caretta, foraging in Azorean waters, are incidentally caught in drifting longlines that target swordfish, Xiphias gladius, and blue shark, Prionace glauca. Data were recorded during a longline gear modification experiment conducted in 2000. The results show that the captures are not uniformly distributed in relation to fishing effort, with 81% of the loggerheads (N = 232) caught in one-third of the sets (N = 93). The highest turtle catch rates were around the eastern group of islands, an area characterized by the presence of mesoscale eddies induced by bathymetric features. High catch rates coincided with the presence of the thermohaline front, between August and October, and when targeting blue shark. To investigate the causes of these differences we fitted a general linear model to evaluate the influence of mean depth, minimum depth, sea surface temperature (SST), soak area, soak time, moon phase and wind force on turtle and target species catch rates. These results revealed that mean depth and SST were most important for loggerhead catch rates, while minimum depth was the only significant variable for swordfish and mean depth, SST, wind force, moon phase and soak time influenced blue shark catches. The distribution of loggerhead sea turtles can be predicted by monitoring fishing areas in relation to bathymetry and SST. The impact of longline fishing could be greatly and quickly reduced by regulating the blue shark fishery and by increasing fishermen awareness for sea turtle conservation.

The taxonomy of pedunculate cirripedes belonging to the genus Pollicipes has essentially remained unchanged since Charles Darwin described them in his exhaustive work on the Cirripedia. This genus includes three species of stalked barnacles: Pollicipes pollicipes in the north-eastern Atlantic, P. polymerus in the north-eastern Pacific and P. elegans in the central-eastern Pacific. However, a population genetics analysis of P. pollicipes suggested the presence of a putative cryptic species collected from the Cape Verde Islands in the central-eastern Atlantic. This study examines the morphology of these genetically divergent specimens and compares them with that of representative Atlantic samples of the biogeographically closely related P. pollicipes and with the poorly described P. elegans. Molecular data, including mitochondrial COX1 and nuclear ribosomal interspaces sequences, were obtained for all species of the genus Pollicipes. Morphological distinctiveness, diagnostic characters, congruent divergence level and monophyletic clustering, at both nuclear and mitochondrial loci support the taxonomic status of this new species, Pollicipes darwini.

The allometric growth of two groups of Nassarius vibex on beds of the bivalve Mytella charruana on the northern coast of the State of São Paulo, was evaluated between September 2006 and February 2007 in the bed on Camaroeiro Beach, and from March 2007 to June 2007 at Cidade Beach. The shells from Camaroeiro were longer and wider and had a smaller shell aperture than those from Cidade; a principal components analysis also confirmed different morphometric patterns between the areas. The allometric growth of the two groups showed great variation in the development of individuals. The increase of shell width and height in relation to shell length did not differ between the two areas. Shell aperture showed a contrasting growth pattern, with individuals from Camaroeiro having smaller apertures. The methodology based on Kullback–Leibler information theory and the multi-model inference showed, for N. vibex, that the classic linear allometric growth was not the most suitable explanation for the observed morphometric relationships. The patterns of relative growth observed in the two groups of N. vibex may be a consequence of different growth and variation rates, which modifies the development of the individuals. Other factors such as food resource availability and environmental parameters, which might also differ between the two areas, should also be considered.