In aquatic food webs zooplankton constitutes an important link between primary producers and higher trophic levels. Copepods often dominate the zooplankton in coastal oceans and are the prey of the majority of planktivorous fish. Feeding behaviour, as well as the food quantity and quality are recognized factors that affect copepod growth, and therefore, the energy transfer efficiency throughout food webs. The natural occurrence and magnitude of these growth factors and their combined effects on marine copepods, as keystone grazers in the pelagic marine realm, are poorly understood. Here, we assessed how these different factors vary throughout the year, and then examine their relative influence upon copepods maximal growth rates. A multiple regression model, including all variables previously selected, and the inclusion of the sea temperature allowed us to estimate the pure influence of the studied factors, and the environmental effect on copepod growth rates. The results imply that ingestion of diatoms may induce a positive effect on specific growth rates of copepods, and the quality of this food item (high PUFA and HUFA availability) might explain such effect. Therefore, seasonal variability in diatom abundance, possibly driven by changes in the oceanographic regime, should be considered a critical factor controlling copepod growth in productive coastal ecosystems.

In order to investigate the intensity and variability of fouling recruitment on artificial hard substrates, three sites were chosen in the First Inlet of the Mar Piccolo of Taranto (Southern Italy, Ionian Sea). Taxa richness and percentage coverage were examined in three different sampling times within each site. Differences were tested both by univariate and multivariate statistical analysis (ANOVA, SIMPER and MDS). The results show that each site seems to be characterized by its own structural make-up over the whole period of observation, underlying the presence of large-scale variability. By contrast, variability on a smaller scale within each site (replicates) appeared less marked, both in space and time. A set of a quite stable group of species characterized each site. Differences between sites were maintained over time with a difference in community evolution although with a tendency towards a higher similarity in species composition along the time.

The burrow morphology of the mud shrimp Upogebia yokoyai was investigated on a tidal flat in the Nanakita River mouth in north-eastern Japan using in situ resin casting. A total of 26 burrow casts were recovered, including those of 16 large shrimps and 10 small shrimps. Burrows of large shrimp were relatively simple and Y-shaped with depth exceeding 1.2 m. Although burrow diameter was related to shrimp size, correlation with other burrow measurements was low. Three large casts were connected to others via a narrow horizontal portion potentially reflecting mating behaviour of the shrimp. Burrows of small shrimp were more complex than those of the other upogebiids and were connected to large burrows. In 6.7% of cases, bopyrid isopods were present in the branchial chamber. Three species of gobies were found in the burrows. These data show that burrows of U. yokoyai serve not only as a recruitment site for conspecific shrimp, but also as habitat for other animals in the tidal flat.

Stenopodidae comprises about 28 species in tropical and subtropical waters around the world, but only two of them in the South Atlantic Ocean (SAO)—Stenopus scutellatus and S. hispidus. Larvae of S. scutellatus were never registered in SAO and those of S. hispidus remain poorly researched. The present study fully describes first to seventh zoea of S. hispidus collected in the plankton of SAO, adjacent to Brazil. In addition, eight larvae of S. scutellatus and two larvae of non-identified Stenopodidea from the same area were also described.

Bright green auto-fluorescence was observed in the umbrellar margin, umbrellar marginal warts, tentacular bulbs, tentacles, and manubrium of laboratory-reared immature (1–14 days old) medusae of Eutima japonica from Japan and China. In vivo microscopic fluorescence spectra showed that the green fluorescence was similar to that of green fluorescent protein (GFP) found in Aequorea victoria, although the maximum emission wavelength (503 nm) was slightly bluer. No fluorescence was detected in the cirri, statocysts, radial canals, velum, or subumbrella of the medusae. The fluorescence distribution pattern in E. japonica more closely resembles that of Eugymnanthea inquilina from the Mediterranean Sea than that of Japanese Eugymnanthea japonica, which is the derived species of E. japonica. This suggests that the common fluorescence pattern is convergently evolved in the former two species, perhaps owing to the as yet unclarified physiological and/or ecological function of GFP and/or GFP-like proteins.

The wide-eyed flounder Bothus podas podas is a small fish that belongs to the Bothidae family. This species is a demersal fish inhabiting sandy and muddy bottoms where it lives buried in the sand. In the Gulf of Gabès (Tunisia), B. podas podas is an uncommon fish caught in small quantities by trawlers, between depths of 20 and 50 m. There are very few complete studies of the biology of this fish in the Mediterranean Sea. Even in Tunisia, the biology of B. podas podas is unknown. In addition, it has been noticed that during the last few years, despite having weak commercial value, this fish has attracted the fishermen's attention of the region after the observed reduction in the flat fish stocks, particularly the Egyptian sole Solea aegyptiaca. The aim of this work was to study the reproduction of B. podas podas and determine the sex-ratio, the sexual cycle, the spawning period and the first sexual maturity. The data for this work was collected during the period of May 2004 until September 2005. In general, this study shows that the proportion of sexes is in favour of females and permits us to analyse the sex-ratio variations according to the size and age of the fish. It also seems that males grow faster than females. The monthly following of the gonad somatic index (GSI), the liver somatic index (LSI) and the condition factor (K) enabled us to determine that the period of maturation occurs from May to August, to define the spawning period from August to November and to deduce that B. podas podas uses the lipid reserves accumulated in the liver to develop its gonads. Concerning the first sexual maturity it was noted that the main size related to 25%, 50% and 75% of matured individuals were respectively for males: 19.68 cm, 21 cm and 22.34 cm and for females: 18.87 cm, 20.4 cm and 21.93 cm. The coefficients of the logistic function were for males: a = 0.827, b = 17.38 and for females: a = 0.718, b = 14.65.

A positive relationship between the number of locations where a species occurs and the average density of individuals across those locations has been found in a wide variety of taxa and has been described as one of the most general and widespread relationships in macro-ecology. However, exceptions to this general rule have been found and this study tested whether abundance–occupancy relationships exist within the cetacean community of the west coast of Scotland. Data were collected in 2003–2006 and occupancy rates were calculated and compared to two density indices (relative density of groups per km2 surveyed and relative density of individuals per km2 surveyed) for four cetacean species (harbour porpoise, bottlenose dolphin, common dolphin and minke whale). Significant positive intraspecific abundance–occupancy relationships were found for both relative density of groups per km2 and relative density of individuals per km2 for two out of the four cetacean species tested (harbour porpoise and minke whale). When the relationships between the different species were compared, all four were found to conform to the same interspecific relationship when relative density of groups was used as the density index. However, some species were found to conform to different relationships when relative density of individuals was used as the density index, potentially due to differences in social structure between cetacean species. These relationships mean that when cetaceans are at a higher density within an area, they also occupy a greater number of locations and vice versa. The existence of positive abundance–occupancy relationships in cetaceans has a number of potential implications for their conservation and management. In particular, it means that when a potential impact is likely to positively or negatively affect the size of the range of a species or population, such as noise pollution or climate change, it is likely to also affect the species' or population's abundance in the same direction. It also has implications for the design and extent of protected areas, such as marine protected areas; as such relationships could be used to determine the area required to maintain a viable population size.

Fatty acids composition of two marine copepods, Acartia tonsa and Centropages brachiatus, and lipid profiles of natural food assemblages were studied during the austral summer 2006 at three upwelling sites in the coastal upwelling zone off Chile, along with oceanographic conditions. Fatty acids of food supply were assessed for the picoplankton, nanoplankton and microplankton size fractions. There were marked differences in upwelling conditions among locations, as well as in their food supply in terms of quantity and quality. Differences in fatty acid composition were also found, both among food assemblages and between copepod species. Essential polyunsaturated fatty acids (PUFA; linoleic acid) and monounsaturated fatty acids (MUFA; oleic acid) dominated the picoplankton and nanoplankton size fractions of food, and they were highly represented in both species of copepods, indicating these size fractions were the major contributors to their diet. These fatty acids can thus be considered as useful trophic markers for copepods. Variation in lipid profiles between species depended on sampling sites, whereas differences in lipid composition among sampling sites were attributed to distinct upwelling conditions, which drive the changes in food quality, such that trophic response is highly dependent on food offer. Variation in fatty acids compositions of copepods may thus act as an indicator of upwelling variability. Our findings suggest that lipid transfer from primary producers to primary consumers can have a crucial role for carbon cycling in the marine food web, and that picoplankton and nanoplankton fractions are the key items of copepod diet in this upwelling system.

During a parasitological survey of the brown mussel Perna perna from highly productive culture fields in the southern sector of Brazil, monstrilloid copepods were discovered in the mantle of this mytilid bivalve. Numerous specimens of endoparasitic copepods were found within nodules in the mantle of the host; they belong to an undetermined species of Monstrilla. Monstrilloid copepods were known to be endoparasitic in polychaetes and in one species of prosobranch mollusc only; their occurrence as parasites of bivalve molluscs has not been previously documented. This is also the first record of these crustaceans infecting commercial molluscs. The prevalence of Monstrilla sp. infecting the brown mussel was 25.6%. At the histological level, it was observed that the larvae induced a strong haemocytic infiltration resulting from the complete larval encapsulation within the host mantle. The effect of this monstrilloid in the cultured populations of P. perna deserves further study.

In addition to the spicules typically produced by sponges, about twenty hypercalcified species belonging to both classes Demospongiae and Calcispongiae secrete a massive basal calcareous skeleton composed of calcite or aragonite. Skeletal growth rates and growth mechanisms are still poorly known in those hypercalcified Calcispongiae. In situ calcein staining experimentation on the Mediterranean calcisponge Petrobiona massiliana revealed a mean annual growth rate of the massive skeleton of 236 µm/y (±90). Scanning electron microscopy (SEM) revealed that some spicules are entrapped within the massive skeleton (a solid mass forming apical crests with multidirectional growth axes) during its formation. Whole actines were observed within the massive skeleton of fractured specimens, indicating that they do not dissolve after entrapping. Calcein incorporation bands seen through epifluorescence microscopy and SEM morphological observations of the skeletal surface revealed cone shaped protuberances corresponding to active growth areas. A spatially discontinuous growth was highlighted, but the annual growth rates were similar at the tip of crests and at the bottom of depressions separating them. The skeleton of P. massiliana is composed of magnesium calcite with strontium as the main trace element. Significant differences in skeletal chemistry of specimens collected in different Mediterranean locations revealed a possible temperature dependence of Mg/Ca. Although such temperature signature exists in the massive skeleton of P. massiliana, its use as an accurate environmental recorder is limited by several factors including multidirectional and spatially discontinuous growth.

The prevalence and infestation intensities of Octolasmis lowei in the branchial chambers of Libinia spinosa were evaluated according to the host's sex, size, and moult condition. Epibionts were classified as cyprid larvae, non-ovigerous or ovigerous according to their developmental stage. A median intensity of infestation of 21 epibionts/host was found (range = 1–644; Q3 = 81). Epibiont prevalence values (88%) were higher on ovigerous female hosts than on males (55%) or on non-ovigerous females (31%). Intensity of infestation was positively correlated with host size in both sexes for non-ovigerous and ovigerous epibionts. No preference between host sex by cyprid larvae was observed, nor any correlation between cyprid abundance and host size. Cyprid larvae abundance was positively correlated with settled epibionts on both host sexes. The duration of the intermoult phase was the main factor linked to the establishment of sessile epibionts. These observations are important in relation to crabs that have a terminal moult, because these animals cannot eliminate their epibionts in future moults, thus increasing the importance of density-dependent mechanisms on epibiont establishment; in that way, prevalence of infestation alone can underestimate the real impact of infestation on the host's life cycle.

Historical science may play an important role in helping understanding and shaping the future of the world's oceans and to comprehend present day effects and conditions. Regarding cetaceans, historical accounts may be extremely useful to add new data to their occurrence and distribution in poorly studied regions. In Portugal, historical sources indicate that toninhas (possibly common dolphins Delphinus delphis) were observed since the 13th Century and were captured in large numbers during the late 19th and 20th Centuries. Historical occurrences given by naturalists and scientific surveys conducted by biologists indicate their regular presence with particular preference for certain areas. Also, recent observations of opportunity resulted in the same kind of accounts. Between 1976 and 1978, a study on captured cetaceans along the Portuguese shore found at fish markets was conducted and resulted in a total count of 45 cetaceans. Most captures were of small cetaceans (87% common dolphins), even though four baleen whales were registered. These cetacean captures were part of a local non-industrial fishery, as they were not the main target, but rather opportunistic catches or even by-catches of other fisheries. Delphinids were not protected by law at the time and were caught with hand harpoons or accidentally drowned in fish nets, sometimes sold at major fish markets such as Sesimbra, Peniche and Póvoa de Varzim. In geographical areas where recent cetacean sightings are rare and information is sparse, such as Portugal, it becomes important to take advantage of alternative sources of data. Our contribution towards the compilation of relevant historical and ‘forgotten’ science such as old natural observations, whaling data and observations of opportunity stresses the relevance of using historical data to access past occurrence and distribution of cetaceans.

The relative importance of parental diet/population and larval diet were examined on egg, growth, morphology and biochemistry of Sclerasterias mollis larvae. Adult S. mollis were fed one cockle (Austrovenus stutchburyi) per two animals each week, as a low diet, or two cockles per animal each week, as a high diet. The experiment was run for one year. In addition, two field populations (Otago inshore and offshore) with dissimilar nutritional status (based on the gonad index) were selected. Otago inshore starfish had higher gonad indices and assumed to have better nutritional status. The low and high diet laboratory starfish produced eggs with similar characteristics. Eggs from the low diet laboratory parents had the highest carbohydrate concentration. The eggs from the field parents had higher fertilization rate and lower carbohydrate concentration than eggs from the laboratory parents. The Otago inshore starfish had smaller eggs with a lower carbohydrate concentration than the starfish from Otago offshore. Parents from the laboratory or the field had significant effects on larval growth, morphological phenotypic plasticity (measured by the body length relative to the body width) and development rate. Larvae from Otago offshore parents had highest growth and morphological phenotypic plasticity. Larvae from the low diet laboratory parents and those from Otago inshore had the highest development rate. Larvae from low diet laboratory parents had the highest carbohydrate concentration. Neither the parents nor the larval diet had a significant effect on larval mortality. A higher concentration planktonic diet resulted in higher growth, morphological phenotypic plasticity and development rate. Parents were however more important than larval diet on growth and phenotypic plasticity of the larvae. This study showed that parental nutrition has an important effect on growth, morphological phenotypic plasticity and body composition of S. mollis larvae. The nutritional status of the parents does not influence the larvae through a change in the egg size, protein, lipid, carbohydrate and energy content.

The summer spatial distribution of the phytoplankton community in the Gulf of Gabès (Tunisia, eastern Mediterranean Sea), together with environmental factors, were studied during a preliminary study conducted in July 2005 aboard the RV ‘Hannibal’. The phytoplankton community, which showed a decrease in concentration along a coastal–open sea gradient, was dominated by Dictyochophyceae (41%) followed by Dinophyceae (25%), Bacillariophyceae (16%), Cyanobacteriae (17%) and Euglenophyceae (1%). The phytoplankton found along the coast was dominated by opportunistic species (e.g. Dictyocha fibula) associated with high nutrient availability. In the open sea, phytoplankton development seemed influenced by Atlantic hydrodynamics. In addition, the Gulf of Gabès is characterized by an oligotrophic status with a summer stratification that impacted on species composition especially in off-shore areas. The coupling of phytoplankton dynamics to nutrients, ciliates and copepods showed the potential role played by ciliates not only as predators of phytoplankton but also as prey for filter-feeding copepods accounting for the increased fisheries productivity of the Gulf of Gabès.

Greater understanding of patterns of distributions of organisms and their causal mechanisms are required if the consequences of climatic change are to be fully realized. Associations between topographic features of the environment and distributions of organisms are frequently assumed to be a consequence of provision or modification of local conditions by those features. Such assumptions are rarely supported empirically and there is increasing evidence that topographic features do not always influence variables in the way we might anticipate. Thus, data about how features of habitat influence environmental conditions, including availability of food, are likely to be useful for understanding how and why organisms are found where they are. Such data are few and rigorous descriptions about what defines particular features of habitat are seldom provided or are simplistic. For hard substrata in aquatic environments, crevices are often prominent features with which many species associate. Crevices have frequently been assumed, but not demonstrated, to ameliorate conditions by increasing humidity, moderating (usually reducing) temperatures and by decreasing forces from wave-impacts and water-flow. This study provided clear definitions and tests of various hypotheses about how crevices altered the local environment. The main predictions were that crevices would be cooler, more humid, more sheltered from water-movement and support more micro-algae than areas away from crevices. Manipulative experiments using artificial habitats and measurements on natural rocky shores were carried out on multiple shores over two years to understand how crevices affected local conditions. Crevices were indeed cooler, more humid, supported more micro-algae and more sheltered from water-flow than open areas nearby, but conditions did not always vary in ways that were expected. Effects were often complex, with factors such as season, height on the shore and tidal conditions interacting to influence how crevices affect environmental conditions. Without this detailed information, assumptions about the reasons animals associate with features of habitat cannot be tested.

The colossal squid (Mesonychoteuthis hamiltoni) is the world's largest invertebrate and its large size and some unique morphological characters have fuelled speculation that it is an aggressive top predator in the circum-Antarctic Southern Ocean. Here, we present estimates on the metabolic and energetic demands of this cold-water deep-sea giant. The estimated mass-specific routine metabolic rate for the colossal squid at 1.5°C was 0.036 µmol O2 h−1 g−1 and the projected daily energy consumption (45.1 kcal day−1) was almost constant as a function of depth in the nearly isothermal Antarctic waters. Our findings also indicate the squid shows a slow pace of life linked with very low prey requirements (only 0.03 kg of prey per day). We argue that the colossal squid is not a voracious predator capable of high-speed predator–prey interactions. It is, rather, an ambush or sit-and-float predator that uses the hooks on its arms and tentacles to ensnare prey that unwittingly approach.

The effect of short-term (5 days) exposure to CO2-acidified seawater (year 2100 predicted values, ocean pH = 7.6) on key aspects of the function of the intertidal common limpet Patella vulgata (Gastropoda: Patellidae) was investigated. Changes in extracellular acid–base balance were almost completely compensated by an increase in bicarbonate ions. A concomitant increase in haemolymph Ca2+ and visible shell dissolution implicated passive shell dissolution as the bicarbonate source. Analysis of the radula using SEM revealed that individuals from the hypercapnic treatment showed an increase in the number of damaged teeth and the extent to which such teeth were damaged compared with controls. As radula teeth are composed mainly of chitin, acid dissolution seems unlikely, and so the proximate cause of damage is unknown. There was no hypercapnia-related change in metabolism (O2 uptake) or feeding rate, also discounting the possibility that teeth damage was a result of a CO2-related increase in grazing. We conclude that although the limpet appears to have the physiological capacity to maintain its extracellular acid–base balance, metabolism and feeding rate over a 5 days exposure to acidified seawater, radular damage somehow incurred during this time could still compromise feeding in the longer term, in turn decreasing the top-down ecosystem control that P. vulgata exerts over rocky shore environments.

A series of visual–acoustic surveys were carried out in the Mediterranean Sea between 2003 and 2007 from RV ‘Song of the Whale’. Almost 21,000 km of trackline were surveyed between the longitudes of 14°W and 36°E with an emphasis on regions with low survey effort. Survey tracklines were designed to provide even coverage probability with random start points. Ten cetacean species were positively identified (sperm whale, fin whale, Cuvier's beaked whale, false killer whale, long-finned pilot whale, Risso's dolphin, common bottlenose dolphin, rough-toothed dolphin, striped dolphin and short-beaked common dolphin). Several of these species, plus sei whale and harbour porpoise, were also encountered in the Atlantic contiguous area (the entrance waters of the Mediterranean between the Iberian Peninsula and north-west Morocco). These surveys expand and clarify the known distributions of cetaceans within the Mediterranean basin. New species documented from Libyan waters include sperm whale, striped dolphin and rough-toothed dolphin. False killer whales and rough-toothed dolphins were documented for the first time off Cyprus. Live harbour porpoises were seen for the first time on Morocco's Atlantic seaboard. It is suggested that the status of rough-toothed dolphins in the Mediterranean be revised from visitor to regular species. Substantial new information on encounter rates is now available for the planning of a basin-wide systematic survey of cetaceans within the Mediterranean Sea and contiguous Atlantic waters.

The present study describes the reproductive biology, population structure and life history traits of the abundant intertidal crab Xantho poressa. Between March 2007 and April 2008, a total of 1918 individuals were collected in Corrales de Rota (south-western Spain), a human-modified intertidal habitat characterized by an artificial high complexity. Suitable refuges for crabs (cobbles and boulders) are very abundant in this area and density (maximum of 50 ind*m−2) was directly related with the area covered by these stones. In spring and summer, size–frequency distributions showed a polymodal pattern with seasonal variations related to the incorporation of juveniles to the adult population. Newly settled juveniles were not found in the Corrales suggesting an ontogenetic migration from a distant recruitment habitat. The annual reproductive cycle was seasonal and successive peaks in the abundance of ovigerous females were observed in late spring and summer. Females probably produced multiple broods during a long intermoult period. The gonadosomatic index had a cyclic pattern of variation with peaks two weeks prior to those of ovigerous females; it was lower during the non-reproductive season. The hepatosomatic index was high during spring, decreased during summer and increased gradually at the end of the reproductive season. There was a monthly cycle of larval release resulting from a combination of a cyclic and synchronic ovarian maturity, oviposition and incubation; hatching took place during neap tides when the moon was at last quarter. The adaptive significance of the rhythmic reproduction and hatching observed may not be explained by the predator avoidance hypotheses. The overall sex-ratio did not differ from 1:1 but one male and several females coexist under a stone, indicating a female biased operative sex-ratio. The combination of a complex habitat, its use, and a strong sexual dimorphism suggest a refuge–defence polygenic mating system. The survival and fitness of X. poressa in the Corrales de Rota are probably enhanced by the availability of shelter, a consequence of a highly complex habitat, and probably, of human activity.

In October 1991, invertebrate larvae abundances were analysed to study the influence of the disturbance of the Canary Current flow by the Canary Islands archipelago on the variability of larval distribution. Two transects and two time-series stations located to the north (non-perturbed zone) and the south (perturbed zone) of the Canary Islands were sampled. Oceanographical data showed a highly stratified water column and zonally uniform salinity and temperature seaward of the African upwelling in the non-perturbed zone, while the perturbed zone presented strong turbulence in the form of mesoscale eddies. Invertebrate larval abundances were lower for most taxa studied in the non-perturbed zone and northern time-series station. Significant differences (P < 0.001) of invertebrate larval abundance between the two zones sampled were found. Decapod larvae were the most abundant larval group in both zones. Stations located in eddy structures presented the highest values of larval densities. Specifically, the larvae collected at Station 18, located in the core of an anticyclonic eddy, represented 60±18% of total larvae collected in the south transect. Finally, our results suggest that eddies, mainly anticyclonic eddies, act as a strong larval retention zone south of the islands, and that there is a local northward transport from the Canary Islands.