Phylogeographic inferences concerning marine species are largely based on intertidal species. In high latitudes, intertidal species have been affected by ice coverage and ice scour, and therefore show northern range limitations during glaciations. In this study, we use the subtidal horse mussel (Modiolus modiolus) to investigate whether generalizations about genetic structure of high latititude intertidal species, specifically in the North Atlantic, are representative of other near shore taxa. We analysed genetic diversity, molecular variance, and geographical patterns of genetic relatedness using data from the mtDNA CO1 gene. Although we do find little to no haplotype structure in the North Atlantic, our results show that north-eastern Pacific individuals represent a different haplotype network with no haplotypes in common with Atlantic individuals. Thus, M. modiolus in the Pacific may represent an unrecognized species. Genetic diversity and population expansion times suggest a Pacific origin is most likely, with subsequent dispersal to the Atlantic. The lack of genetic structure in the Atlantic suggests that a rapid range expansion occurred less than 50 KYA, rather than a stepping stone mode of dispersal.

The occurrence and intensity of infection of caligid species on the five species of wrasse commonly found in British waters are reported from twelve localities in the British Isles and from seven fish-farms in Scotland where wrasse are used to remove sea lice from salmon (Salmo salar L.). A low prevalence of infection was recorded for all wrasse species except ballan. Chalimus of Caligus centrodonti Baird were identified from fins of ballan, rock cook and goldsinny wrasse, this being the first host record for the latter two species. Single chalimus stages of Caligus elongatus Nordmann were identified from a ballan wrasse and a goldsinny wrasse and are similarly first records from these host species. No C. centrodonti were found on farmed salmon and conversely no Lepeophtheirus salmonis (Krøyer) were identified from wrasse kept in contact with infected salmon. This suggests that transfer of caligids between wrasse and salmon and vice versa does not pose problems for fish health on sea-farms.

The size at first maturity of the bivalve Brachidontes rodriguezii was estimated in a population located in the northernmost limit of its distribution along Argentinean coast. Specimens were collected in two consecutive reproductive seasons from December 2011 to February 2012 and from December 2012 to February 2013. Individuals were evaluated using biometric and histological analyses of the gonads. This study intended to provide important information about the development of gonadal tissue according to shell length increase. Our results showed immature specimens lack gonads or exhibited groups of cells undergoing mitosis adjacent to the epithelium of the mantle and the tubules of the digestive gland. Male and female gonad development extended to mantle lobes and visceral mass as long as maturation occurred to reach sexual maturity. Using a logistic model our results showed that the size at which 50% of females were mature at a gonadal level was 7.05 mm in shell length; in males, 50% of the population were mature at 8.13 mm in shell length. The minimum shell length at which maturity was observed was 6.99 mm in shell length in females and 6.00 mm in shell length for males.

Ninety-six field trips were conducted between summer 2010 and 2012 in order to understand the occurrence and habitat use of Bryde's whale (Balaenoptera edeni) in the Cabo Frio region, South-eastern Brazil. Bryde's whales were present in the study area between November and July, being observed during all seasons, but occur more frequently during the autumn (Nindividuals = 16) and spring (Nindividuals = 13), followed by summer (Nindividuals = 5) and winter (Nindividuals = 2), respectively. Bryde's whales were observed in water depths ranging from 20.1–100 m. Furthermore, during 2240 min of video recordings, the most frequent behaviour observed was foraging (40.2%; 900 min). Travelling comprised 28.1% (630 min) of observations, while in 33.1% (710 min) behaviour could not be determined. Taking into account the pattern of occurrence, the use of deeper bathymetric bins and the frequency observed, the foraging behaviour of Bryde's whales observed in our study seems to be associated to prey dynamics. Our data show that the study area is frequently used for foraging by this species in Brazilian waters.

A karyometric analysis of the diploid complement of two species of the genus Procerodes (Tricladida: Maricola), both from British waters, has been carried out

The diploid number of Procerodes littoralis, 2n = 14, was established on mitosis from regenerative blastema and the haploid number n = 7 from spermatocyte I stages. All the chromosomes are metacentric, their centromeric index varying from 47·91 in the chromosome 5 to 38·39 in the chromosome 4.

The mantle muscle tissue of cuttlefish is predominantly made up of circular muscle fibres which run around the body. This circular muscle tissue is divided into discrete blocks by radial fibres, which run perpendicular to the main axis of the body. Growth of mantle muscle tissue was described in the tropical cuttlefish Sepia elliptica by examining muscle block size and the density and size distribution of muscle fibres. Changes in these variables were assessed in juvenile and adult cuttlefish. Generation of new muscle fibres, both within new and existing muscle blocks, occurred as animals grew across the size range. Anterior muscle blocks were smaller than muscle blocks in the middle and posterior regions of the mantle, suggesting that new blocks were generated anteriorly. Muscle blocks were also created in the middle and posterior regions by division of existing large blocks into small blocks by generation of circular and radial muscle fibres. The examination of cuttlefish muscle growth dynamics provided an alternative way of assessing cephalopod growth mechanisms.

The first account of mating in a myodocopine using evidence from video recordings is presented herein for Skogsbergia sp. (Cypridinidae). After initial courtship the male and female ostracods, with ventral margins adjacent and anterior ends directly opposite, join their mandibular claws and furcae. Both furcae are pushed in a posterior direction until the ventral margins of the carapace meet. In this position, with genitalia directly opposite, copulation presumably occurs. This mating procedure lasts for five seconds.

Myodocopine ostracods are diverse marine crustaceans occurring world-wide at depths from 0–6000 m (Kornicker, 1975). All myodocopines reproduce sexually (Cohen & Morin, 1990). Some bioluminescent cypridinids (Myodocopina) use luminescent signalling during courtship; males produce species-specific patterns of flashes in the water column to attract females (Morin, 1986). Although myodocopines may be amongst the most abundant macroinvertebrates on the continental shelf (J.K. Lowry, personal communication), they have been the subject of relatively few behavioural studies, and in particular their copulation process is poorly documented (Cohen & Morin, 1990).

Two accounts of myodocopine mating have been reported. In 1914 the cypridinid Vargula hilgendorfii (Muller, 1890) was observed mating in a Petri dish (Okada & Kato, 1949). The male clasped the female using the first antennae while swimming with the natatory second antennae. After 30 to 60 min they rested on their lateral sides, with ventral margins touching and heads facing in opposite directions; the penis (lying between the paired copulatory ‘limbs') was protruded into the female carapace and the spermatophore was transferred. This copulation lasted more than 30 min (Okada & Kato, 1949).

Guanine and hypoxanthine were excellent sole nitrogen sources for several microalgal species grown in axenic culture. Of the algae studied only Chlorella stigmatophora grew well on pyrimidines. Freshly harvested nitrate or ammonium-grown organisms generally lacked ability to take up guanine or hypoxanthine but this ability developed during several hours of photosynthesis in nitrogen-free medium. Nitrate-grown (but not ammonium-grown)Tetraselmis subcordiformis and Chlorella fusca could take up guanine, the initial rate of uptake increasing when the cells were also nitrogen-deprived. Of the algae studied only Chlorella vulgarisand Attheya decora required prior incubation with guanine before being able to take it up. Porphyridium purpureum did not take up guanine. Factors affecting the development of ability to take up guanine and the characteristics of guanine transport were studied. The transport systems showed Michaelis-Menten type kinetics with K s values ranging from 05 to 3–7/IM guanine. In marine species, guanine uptake was dependent on the presence of Nations in the medium but Chlorella stigmatophora showed less dependence on Na+ than other species.

Reproductive aspects of the intensively traded ornamental shrimp Lysmata boggessi were examined. Abundance, reproductive biology (fecundity, reproductive output and egg size) and population structure (frequency distribution, size at sex phase change and sex phase ratio) were examined at three different fishing grounds off south and west-central Florida between May 2011 and February 2012. Fishery-dependent densities of L. boggessi varied between 2.51 ± 1.39 and 13.05 ± 9.30 shrimps per 1000 m2 at two different localities. The proportion of brooding shrimp varied considerably at one locality during two different dates, suggesting reproductive seasonality. Reproductive output increased linearly with shrimp body weight (SBW) at one locality (May 2011), but scaled negatively with SBW at a second locality (January–February 2012). Lastly, no correlation between embryo size and shrimp carapace length (CL) was recorded at one locality (May 2011), but a slight negative correlation between embryo size and CL was found at the second locality (January–February 2012). Lysmata boggessi might be experiencing trade-offs between different reproductive parameters driven by environmental, probably seasonal, conditions during the year. All of this information needs to be considered in assessing shrimp stocks and establishing a sustainable management plan.

Predictions that there should be more benthic invertebrates and greater diversity in deeper areas and differences in the spatial structure of assemblages on different types of beaches were tested on two Reflective and two Intermediate (Transverse Bar and Rip) sandy beaches around Sydney, New South Wales, Australia. The macrofaunal assemblages of surf zones were more diverse and there were more invertebrates on Reflective than TBR beaches, and there was an increase in number of invertebrates and, significantly, in diversity from 1·5 to 2·5 m depths. There was significant variation in the structure of assemblages among beaches of the same type. Spatial variability in the structure of assemblages on Intermediate beaches was greater than on Reflective beaches. Macrofaunal assemblages varied significantly at a scale of tens of metres across shore, particularly on Reflective beaches.

Vertical distribution of fish larvae can be modified by a series of physical processes occurring in the water column at different time and spatial scales and also by biological processes occurring during larval development. To assess the factors affecting the vertical distribution of larval anchoveta Engraulis ringens during austral spring, meteorological and oceanographic features were measured and stratified ichthyoplankton sampling was carried out in central Chile during active upwelling events. In November 2001, during the upwelling season, southerly winds dominate, and intrusion of low dissolved oxygen occurred in nearshore waters; preflexion larvae of E. ringens were collected in the mixed layer of the water column (the Ekman layer) irrespective of day and night hours. Larvae larger than 10 mm showed an inflated gas bladder during night collections, and non-inflated gas bladder during day hours. Larvae with inflated gas bladders were located significantly at shallower depths during night than at day hours, indicating a direct relationship between gas bladder inflation, diel vertical migration of larval E. ringens and decrease of wind-induced turbulence at night. We discuss the potential implications of larval E. ringens vertical distribution and its variability on the horizontal transport off coastal waters during the upwelling season off central Chile as a biophysical coupling to enhance coastal retention.

Every year, an undetermined number of loggerhead turtles cross the Gibraltar Strait entering and going out of the Mediterranean Sea. An unknown percentage of them strand on the Andalusian beaches, alive or dead, with an unequal distribution along the coast. We found a geographical pattern in the density of strandings, as well as in the proportion of them that were alive and dead. Atlantic areas receive a higher number of strandings, although most of them correspond to dead individuals, especially on the west coast (province of Huelva), whereas on the Mediterranean coast there is less difference between the number of alive and dead turtles stranded. The causes of stranding also presented a spatial segregation along these coasts: net fisheries were concentrated in Huelva, cold stunning was more frequent in Atlantic Cádiz, and debilitated turtle syndrome and longline were biased to the Mediterranean coast. The Atlantic areas might be an important accumulation zone for turtles, but where they endure a high human-induced stress and mortality. In the Mediterranean area, different causes, such as the narrowness of the Alborán basin, the ocean currents, human activity, or the number of turtles crossing, may increase the number of turtles stranding alive on the coast.

The amino-acid composition of Balanus balanoides (L.) and B. balanus (L.) da Costa eggs during their development has been investigated. Protein accounts for 70–80% of the dry matter. The amino-acid composition of the eggs is similar to that reported for Calanus finmarchicus, for which reliable information is available. Loss of all amino acids takes place during development, but the relative amounts of glycine and alanine increase in the late stages. The rates of loss are far greater in B. balanus, where the eggs themselves develop more rapidly. In B. balanoides there is a distinct ‘ arrest’ in the rate of loss of amino acids at the H-stage; this is coincident with a similar arrest in the loss of other metabolites and in development. Loss of nitrogen from the eggs has been measured directly and the results compared with the values calculated from the analyses. In the early stages the agreement is good if allowance is made for the difference in temperature between the elution experiments and the natural environment.

Data have already been presented (Barnes, 1965; Dawson & Barnes, 1966) on the major biochemical constituents of the eggs of two common cirripedes, Balanus balanoides and B. balanus, and on changes in these constituents during development. It has been shown that protein nitrogen is lost throughout development and that the rate of this loss is greatest during the early stages; also that nitrogen utilization relative to that of carbohydrate is greater in B. balanus. The more rapid development of the eggs of the latter species gives rise to a greater rate at which all substrates are utilized, but the proportions disappearing—relative to the initial quantities—are not widely different; rather more is lost in the species that develops more rapidly.

In a survey of the British species of Gammarus inhabiting estuarine waters (Spooner, 1947), it was found necessary to divide G. zaddachi Sexton into two well-marked morphological forms, with different salinity optima, which in fact behave as distinct species. They were, however, on account of their similarity in important structural features, retained as a single species and named G. z. zaddachi and G. z. salinus respectively. At the time little could be said about a third subspecies, essentially marine in its distribution (but ranging into brackish water), which Segerstråle (1947) independently described as G. z. oceanicus.

The family Myidae is represented in British seas by the two large and well-known species, Mya arenaria L. and M. truncata L., which burrow deeply into muddy sand and into stiff mud or clay respectively, and by the much smaller Sphenia binghami Turton. Interest in members of this family of Eulamellibranchia was aroused during 1949 when studying two species which are common along the coast of California, namely Platyodon cancellatus (Conrad) and Cryptomya californica (Conrad). These differ most interestingly in habitat. The former bores into soft rocks between tide marks, and the latter, although practically devoid of siphons, burrows deep in the mud of tidal estuaries, always in association with burrows made by various large invertebrates. The species most usually involved is Callianassa californiensis, a large anomuran prawn (McGinitie, 1935). The almost sessile siphons open into the sides of the burrows. Accounts of both species have been prepared for publication in California.

The larval shell morphology of 10 bivalve species of the family Mytilidae (Adula falcatoides, Crenella decussata, Crenomytilus grayanus, Modiolus kurilensis, Musculista senhousia, Mytilus coruscus, Mytilus galloprovincialis, Mytilus trossulus and Septifer keenae, and an unidentified species Mytilidae indeterminate) from the Sea of Japan is described. The following morphological features were comparatively examined: larval shell outlines including shape and size of umbones, and anterior, posterior and ventral margins, hinge morphology, ligament location, sculpture, colour, and eye-spot outlines. Some dimensional parameters of larval shells are given. The time interval of occurrence of larvae in the plankton, water temperature in this period, and shell length of competent larvae are presented. It is demonstrated that, in spite of sometimes similar external morphological characters, identification of mytilid larvae creates no difficulties if all distinguishing characters are used.

Previous scientific studies have listed chemical compounds from sea cucumber species. The ability to produce bioactive metabolites derives from their response to various ecological stresses and avoidance of predation. In view of this, the present work aimed to evaluate the antibacterial activity and quantitatively assess the active components of different organs of the sea cucumber Holothuria foskali collected from the north-east of Tunisia. The antibacterial activity of ethyl acetate extracts was tested against Bacillus subtilis, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. It was revealed that Escherichia coli and Bacillus subtilis were inhibited by the sea cucumber extracts. To identify the composition of these extracts, Gas Chromatography-Mass Spectroscopy (GC-MS) and Liquid Chromatography-Mass Spectroscopy (LC-MS) methods were used. The GC-MS revealed the presence of 25 major components, the most concentrated ones were characterized as C26H27N5O6 Morphinan-4,5-epoxy-3,6-diol, 6 amino;C17H31F3O2 3-trifluoroacetoxypentadecane; C31H50O2 Stigmasta-5,22-dien-3-ol,acetate; C11H14O2 1-Phthalanol,1,3,3-trimethyl 1-phenyl; C30H48O2 Ergosta-5,22-dien-3-ol,acetate and C25H40O2 (9E)-8-Phenyl-9-octadecenoic acid methyl ester; while the LC-MS revealed the presence of eight molecules, identified as phenolic acid, phytosterol and fat-soluble vitamins. Some molecules are interesting and deserve to be explored for their potential uses as ingredients in functional foods or as raw materials for new drug forms.

Within the COST action EMBOS (European Marine Biodiversity Observatory System) the degree and variation of the diversity and densities of soft-bottom communities from the lower intertidal or the shallow subtidal was measured at 28 marine sites along the European coastline (Baltic, Atlantic, Mediterranean) using jointly agreed and harmonized protocols, tools and indicators. The hypothesis tested was that the diversity for all taxonomic groups would decrease with increasing latitude. The EMBOS system delivered accurate and comparable data on the diversity and densities of the soft sediment macrozoobenthic community over a large-scale gradient along the European coastline. In contrast to general biogeographic theory, species diversity showed no linear relationship with latitude, yet a bell-shaped relation was found. The diversity and densities of benthos were mostly positively correlated with environmental factors such as temperature, salinity, mud and organic matter content in sediment, or wave height, and related with location characteristics such as system type (lagoons, estuaries, open coast) or stratum (intertidal, subtidal). For some relationships, a maximum (e.g. temperature from 15–20°C; mud content of sediment around 40%) or bimodal curve (e.g. salinity) was found. In lagoons the densities were twice higher than in other locations, and at open coasts the diversity was much lower than in other locations. We conclude that latitudinal trends and regional differences in diversity and densities are strongly influenced by, i.e. merely the result of, particular sets and ranges of environmental factors and location characteristics specific to certain areas, such as the Baltic, with typical salinity clines (favouring insects) and the Mediterranean, with higher temperatures (favouring crustaceans). Therefore, eventual trends with latitude are primarily indirect and so can be overcome by local variation of environmental factors.

Temporal and spatial fluctuations of environmental parameters are normally assigned as causes of variations in morpho-phenological characters of seaweeds and in their epibionts, but formal tests of such hypotheses are lacking, especially in narrow gradients. The present study evaluated the influence of a very small depth gradient (1 to 3 m) and of subtle seasonality characteristic of tropical areas on morpho-phenological traits and on the occurrence of sessile epiphytic organisms using a controlled orthogonal sampling design in a sublittoral population of the tropical brown alga Sargassum cymosum. Four temporal samples were obtained over a one-year period at three depths using nine replicates. The wet weight, maximum length, number of primary and secondary branches, and proportion of secondary branches with receptacles were recorded. Epibiosis was estimated by visual evaluation of percentage cover on secondary branches. Algal morphology varied as a function of the period of the year (weaker effect) and depth (stronger effect) but in different ways for each variable analysed. In general, fronds tended to be shorter, heavier, and more ramified in shallower areas. In relation to time, the morphological characters tended mostly to present higher values in January (summer) and/or April (autumn). Frequency of receptacles did not depend on algal morphology and depth at all but varied in time, although only in the deepest area. Epibiosis also did not depend on algal morphology but varied in relation to time (stronger effect) and, to a lesser extent, depth (weaker effect). The effect of time upon epibiosis also depended on the biological group analysed. These data support the hypothesis that algal morphology varies in relation to period of the year and depth, even under small temporal and spatial environmenal gradients.

The mesopelagic alepocephalid fishes Xenodermichthys and Photostylus have unusual compartmented sub-dermal spaces filled with a fluid more dilute than sea water. The fluid is probably lymph, and contributes to the low density of the fish. The external layer superficial to these subdermal spaces consists of cells containing large intracellular paracrystals which form tubular arrays. This external layer is interrupted by numerous photophores (in Photostylus borne on stalks) which have a reddish-violet central core, and are backed by a reflecting layer. The reflector does not contain guanine, it is made up of a series of flattened cells, and reflects blue-green light. The cells of the central core are assumed to be photocytes and are in connexion with apparent nerve terminals, but in neither fish has luminescence of the photophores been observed.