The two zoeal and the megalopal stages of Petrolisthes robsonae, are described and illustrated from laboratory-reared larvae. Larval features are compared with those previously described for other species of Petrolisthes in the eastern Pacific. Larvae of P. robsonae exhibit similar but not identical features to those seen in other Petrolisthes species. A number of similarities are found with P. zacae while main differences are found with P. granulosus,P. platymerus and P. laevigatus. Differences with these species are related to the setation of maxilla and maxillule and the rows of denticles in carapace spines.

The diet breadth and diet overlap of two co-existing species of flatfish, plaice (Pleuronectes platessa) and dab (Limanda limanda) inhabiting a shallow bay in south-west Ireland are compared. They were shown to vary with the resource matrix, the gut region and the sample size. Diet breadth was calculated using Levin's index and diet overlap calculated using Horn's index. Values of diet breadth were considerably less for numerical abundance data when compared to percentage occurrence data. Similarly, diet overlap values were less for numerically derived data. In dab, diet breadths were significantly lower for stomach-only contents than for intestine-only or whole gut contents. In plaice, there were no significant differences in diet breadths between gut regions. Significantly lower diet overlaps for stomach-only data were also found. Reducing the size of sample to N=30 and N=10 resulted in increases in the calculated value of diet breadth, by as much as 0·13 and 0·34 respectively, these increases were frequently significant. The same reductions in sample size for diet overlap decreased overlap values by 0·02 and 0·13 respectively, significant only when sample reduced to N=10.

Vesicomyid clam species are abundant in many deep-sea chemosynthetic communities, including cold seeps. They rely primarily on thiotrophic (sulphide-oxidizing) gill symbionts for nutrition and thus require sulphide-rich environments. Submersible surveys of megafaunal distributions at the Blake Ridge Diapir, a deep-sea methane-hydrate seep located ∼200 miles off the coast of Charleston, South Carolina, documented massive mortalities of vesicomyid clams. The cause of these mortalities is unknown, but sulphide deprivation, sulphide toxicity, and disease are possible agents of mortality in this system. Similar redox profiles in sediment cores from live and dead clam beds do not support the hypothesis that there has been a transient shift in the flux of sulphide. To address the potential for disease as a cause of mortality, we undertook a histological survey of microparasites and other indications of disease in clam tissues. Six morphological types of parasites were identified using light microscopy, including two viral-like inclusions, Rickettsia-like gill inclusions, possible bacterial gut inclusions, bacterial gill infections, and a protistan inclusion. Of these parasites, two were pathogenic: viral-like inclusions in mantle tissues caused tissue degradation; bacterial gill infections resulted in localized disruption and degradation of gill filaments. Infection prevalence and densities were low for all parasites observed. The majority of clams examined showed intense haemocytic responses in the absence of any obvious etiologic agent, suggesting the presence of parasites not detectable by our methods. Our findings indicate that the clam population at the Blake Ridge seep was in relatively good health at the time of sampling.

Sepia officinalis produces a dark ink constituted of a suspension of melanin granules in a viscous colourless medium showing a large variability in composition. The examination of the spectra obtained by scanning electron microscopy of crude and the melanin-free ink showed slight variation in elemental composition related to the elimination of melanin substance after centrifugation. Ink elemental content varied also depending on the period of sampling. Temperature, light and oxygen can be considered as coagulation factors. Temperature around ambient temperature (e.g. 30°C) gave strong coagulation, while lower temperature (2–4°C), lack of oxygen and darkness greatly inhibited the ink coagulation process. Moreover, we showed that hydrogen peroxide activated the ink coagulation process and the coagulation rate depends on the amount of H2O2 added. Heat treatment (100°C for 5 minutes) of ink inhibited the coagulation. Interestingly, the addition of an adequate volume of fresh melanin-free ink to the heated sample activated significantly the coagulation process.

Silver bellies, Leiognathus splendens were studied for their spatial (south-west and south-east coasts of India), annual (2008–2011) and seasonal (pre-monsoon, monsoon and post-monsoon) variations of protein, amino acids, vitamins and minerals. The monthly mean Sea Viewing Wide Field-of-view Sensor data for the period from January 2008 to December 2011 were taken into account to indicate the distribution of the photosynthetic pigment chlorophyll-a to test the hypothesis that surface productivity might be related to nutritional biochemistry of this species. The four year average total protein content and chlorophyll-a showed good correlation during monsoon on the south-west coast and monsoon/post-monsoon on the south-east coast, suggesting that the protein content is prejudiced by the chlorophyll-a concentration. Amino acid scores observed monsoon maxima along the south-west and south-east coasts. Significant seasonal variations in vitamin content were observed at the study locations with high content of vitamins D3, E, K1 and C on the south-west coast. Na content was maximal during pre-monsoon on the south-west coast, while post-monsoon maxima of Ca and K content were observed. The Fe, Mn and Zn were abundant in the samples collected from the south-west coast. The concentration of Se exhibited maximum values post-monsoon along the south-west and south-east coasts. The present study demonstrated L. splendens as a valuable source of the protein, amino acids, minerals and vitamins, showing that this low-value species is a good source of well balanced proteins with high biological value to be qualified as a preferred healthy food for human consumption.

In this research, the feeding guild composition of the polychaete community was described and analysed in the northern Yellow Sea, China. The polychaete feeding guilds also showed a distinct seasonal abundance fluctuation that was similar to that observed for macrofauna. Burrowers were the most predominant feeding guild, whereas filter feeders and herbivores only constituted a negligible proportion of the total abundance. A Spearman rank correlation was performed to analyse the relationships between the feeding guilds and the environmental parameters. Surface deposit feeders and carnivores appeared to be vulnerable to variations of environmental conditions. However, burrowers and filter feeders were not susceptible to the natural or anthropogenic disturbances, with grain size determined to be the only conclusive factor. These results revealed that the feeding guild of polychaetes showed significant spatial and temporal changes, and spatial heterogeneity was a stronger predictor than temporal variation. The feeding guilds of polychaetes can be applied alone to discern the environmental change, which would be faster and more cost-effective with best equilibrium between the precision of the results and a decrease in taxonomic effort. Furthermore, bimonthly sampling was proved to be unessential and reduction of the sampling frequency was necessary to save expense and effort.

Worldwide, infectious diseases represent a leading cause of death and disability. Exposure to the ocean, whether through recreation or occupation, represents a potentially significant, but poorly understood, source of infectious diseases in man. This review describes the potential mechanisms whereby marine bathing could lead to infectious diseases in man. Sources of pathogens in the marine environment are described, including human sewage, animal sources, fellow bathers and indigenous marine organisms. The epidemiological evidence for the association between marine bathing and infectious disease is presented, including a consideration of the differing relationship between faecal indicator bacteria levels and illness at point source compared with non-point source settings. Estimating the burden of infectious disease is reliant on public health surveillance, both formal and informal, which is described from a UK perspective in this review. Potential emerging threats at the marine–human interface are discussed, including infections caused by Shewanella and Vibrio bacteria, and the presence of human pathogens in the marine environment that are resistant to antimicrobials.

Sponges of the Mycale genus are an important source of several bioactive metabolites. The raw materials for studies on this genus mainly come from the wild populations. However, the scarce biomass of sponges in the wild has become an obstacle to the better investigation of the active substances. To establish aquaculture methods based on the sexual reproduction of the demosponge Mycale phyllophila and solve the sponge shortage problems, the sexual reproductive cycle of this species was studied. Our investigation is the first to report the sexual reproduction of the Mycale species in the coastal waters of China. We collected the sponge specimens from Dongshan Bay (Fujian, China) monthly from June 2012 to January 2014. Small samples of approximately 8 cm3 in volume were cut from 15 sponges (10 tagged individuals and five random individuals) with surgical scissors for histological analysis. The results indicated that M. phyllophila is a hermaphroditic and viviparous species. The primary oocytes measured 30–50 μm in diameter, while mature oocytes reached 300–400 µm by engulfing nearby nurse cells. Spermatic cysts containing asynchronous cells were found throughout the mesohyl, especially adjacent to the oscula. Macromeres in the middle and micromeres in the periphery were observed as the cleavage progressed. The reproductive activity of M. phyllophila lasted for 5–6 months and peaked when the average water temperature was above 25°C. This suggests that water temperature is an important environmental factor influencing the sexual reproduction cycle.

The description of the movements and habitat preference of marine fishes is essential to understand their biology and in the evaluation of commercially exploited species and the conservation of endangered ones. In this regard, little is known about the movements of the totoaba (Totoaba macdonaldi), despite its being listed as critically endangered and having been a relevant fishery resource in the past century in Mexico. Totoaba is a fish species endemic to the Gulf of California characterized by late maturation, prolonged life and annual reproduction. Totoaba has maintained its known historical distribution range, although its movements and habitat occupancy in the water column have remained poorly understood. The present study describes, for the first time and at a daily fine scale, the vertical movements and habitat preferences of the totoaba in the Upper Gulf of California. Pop-up satellite archival tags (PSATs) were used to record depth and temperature at 4-minute intervals. Ten individuals were caught and tagged in May 2016 in the Upper Gulf of California and Colorado River Delta Biosphere Reserve. All PSATs were either prematurely released or lost. Data derived from two recovered tags that saved data for 43 and 75 tracking days, respectively, were analysed. The results showed that tagged fishes moved southward to the vicinity of Angel de la Guarda Island; these are consistent with spatial displacement patterns reported in the literature, with a linear displacement of 223 km from deployment to pop-up sites. Fish spent 47% of the time within a depth range of 25–35 m. Depth increased to 70 m for one fish in early summer (late June). The preferred temperature of fishes ranged between 21–23°C. A generalized linear model revealed that vertical movement was influenced by temperature. The vertical displacement of the totoaba shows a diurnal variation that may be associated with the distribution of its prey. Further work is needed to test this hypothesis with a larger number of organisms.

Based on some coincident morphological characters and distribution, it was believed for a long time that Mica micula was the post-larval stage of a species of Bargmannia, a genus having a very wide geographic distribution. Recent studies, however, have shown that it is much more likely to be the post-larval form of the physonect Pyrostephos vanhoeffeni, which is very common in both Antarctic and sub-Antarctic waters. Until now, molecular evidence to support this theory has been lacking. In the present study 34 nectophores of P. vanhoeffeni and four colonies of M. micula collected from three areas in the Southern Ocean were analysed for the 16S rRNA gene. Five haplotypes were identified, which formed two clearly distinct lineages. Three haplotypes were found exclusively in Admiralty Bay and were shared between individuals of both studied taxa, confirming that M. micula is indeed the post-larval stage of P. vanhoeffeni. Two additional haplotypes were found in one open ocean locality and in Admiralty Bay.

During the INDEMARES/CHICA 0610, 0211 and 0412 expeditions, carried out in the northern Spanish sector of the Gulf of Cádiz (Spain), samples were collected with a box-corer in 11 mud volcanoes and their adjacent bottoms. Chemoautotrophic communities were found in nine mud volcanoes. Among Decapoda, a rare eucalliacid, belonging to the genus Calliax and related to the Mediterranean infralittoral species C. lobata (de Gaillande and Lagardère 1966), was present in three of them. Data on its morphology, biogeographic distribution, vertical distribution within the burrows, sediment composition, pH and redox potential values (each in 5 cm intervals) are given; information on the chemoautotrophic communities associated with this species are also provided.

Determining the duration and timing of spermatogenesis in Mytilus californianus Conrad became key questions in our study of carcinogen-mutagen indices in the marine environment. We had postulated that the murine sperm deformation assay of Bruce, Furrer & Wyrobek (1974) should have marine analogues, and we assayed a number of marine invertebrates sampled near potentially carcinogenic waste flows, and by γ-ray dose-response experiments. Our field results demonstrated some deformation but only at a very low level (less than 5 % in Mytilus edulis L.). Development of a γ-ray doseresponse (90–900 rads) procedure for M. californianus by radium needle inserted through a drilled hole closed with a plastic plug, and subsequent biopsy of gonadal tissue at measured distances from the site of irradiation, did not show deformations from a pilot test in June 1979. If a viable dose-response procedure was to be developed it was necessary to establish seasonal reproductive timing so that specimens could be collected or cultured to maximize spermatogenesis and hence response potential, and also to establish the duration of spermatogenesis so that response measures via a gonadal tissue extraction could be appropriately timed.

This paper describes the incidence and pathology of a copepod parasite (Sarcotaces sp.) in two species of deep-sea bottom-living fish. The fish Lepidion eques (Moridae) and Coelorynchus occa (Macrouridae) are common on the continental slope to the west of the British Isles at depths from about 400 to 1300 m and 700 and 2000 m respectively.

In both species the parasite was located beneath the skin. In L. eques it was found primarily on the head, whereas in C. occa it was present on the mid to lower flank, often close to the anal vent. Excision of the parasite from the host tissue showed it to consist of a pyriform sac filled with inky black fluid. Detailed histological investigations revealed the parasite wall to be a highly complex structure. Within the gut fluid shown to be of haematogenous origin, numerous copepod nauplii were often observed.

A new species of Biemna, Biemnastrongylota sp. nov. is described from Antarctica. The new species is compared to other Antarctic species of Biemna, B. chilensis and B. macrorhaphis from which it differs in that it possesses strongyle megascleres, instead of styles, and of the microsclere complement which includes microxeas, raphides and two categories of sigmata.

A number of records from echo-sounders have been loosely attributed to the presence of plankton. Only two records have been adequately identified as having been produced by plankton; first, the traces offish larvae, or shallow scattering layers (Burd & Lee, 1951); and secondly, the echo layer, at the depth of the temperature discontinuity or thermocline, which is sometimes associated with plankton animals or plants (Cushing, Lee & Richardson, in press). A third type of record, that from the ‘deep scattering layer', has been associated with the presence of euphausiids (Hersey & Moore, 1948; Moore, 1950; Boden, 1950): an equally plausible association with the presence of fish has been made by Marshall (1951), Tucker (1951) and Hersey & Backus (1954). A fourth type of echo record, a ‘noisy’ record, will be described and will show that it is probably attributable to plankton organisms, consisting, in one instance, of euphausiids.

Interindividual trail following by the patellid limpet Cellana toreuma was studied by field observations for more than ten successive days in the non-reproductive period. This behaviour was more frequent during spring tides than neap tides, when the limpets were moving longer distances in response to greater tidal amplitudes. Small individuals performed this behaviour with longer distances and higher frequencies than did larger individuals. Path analysis revealed that total distance moved during foraging excursions and mean resting site height had direct and indirect positive effects on the frequency of the interindividual trail following, respectively, and shell length and frequency of intraindividual trail following exerted a direct, negative effect.

The infauna of Chabahar Bay (Iranian Coast of the Gulf of Oman) was investigated using shallow water (less than 10 m) grab-samples between June 2013 and March 2014. The magelonid fauna of these samples was studied and prioritized, with four species being present: M. fauchaldi sp. nov., M. symmetrica, M. cf. cincta and M. crenulifrons. The new species differs from all known magelonid species within the Persian Gulf region in possessing polydentate abdominal hooks. A fifth species, currently undescribed, was also found. The validity of M. pulchella originally described from Kuwait is discussed in light of its closeness to M. crenulifrons. The main distinguishing feature between the two species is the presence or absence of crenulation of the anterior prostomial margin, a character shown to be variable in M. crenulifrons. Although differences between the type specimens of both species suggests M. pulchella to be a valid species, examination of further material and DNA analysis is needed.

The larva of the compound ascidian Polyclinum aurantium Milne Edwards (1842) has been described by Berrill (1950), and his figures and description indicate a dissociation between the ampullae and epidermal vesicles. A reexamination of the larvae of this form shows that this is a false disjunction. This is most evident in the younger stages. Berrill describes (p. 46) a ring of eight ampullae, in the larva of Polyclinum, surrounding the anterior tip of the trunk, and ‘numerous epidermal vesicles growing out or detached from two long strands reflected posteriorly” (p. 89).

The present study was undertaken in order to analyse whether macrobenthic communities can or not be used in monitoring programmes of the environmental quality of fish ponds. Functional community analysis and biotic metrics were analysed aiming at the assessment of their effectiveness in discriminating potential impacts of fish production in these systems. The macrofaunal patterns in earthen fish ponds of the Ria Formosa lagoon showed to be influenced by the input of fish food during the production cycle and by changes in abiotic parameters caused by seasonality and fish production. Polychaetes were generally dominant considering the number of taxa and abundance. The trophic functional analysis of the benthic communities showed that the deposit-feeding functional group dominated in both areas of the ponds but within water entrance areas there was an increase of suspension-feeding, carnivory and herbivory feeding modes. The presence of less trophically mixed communities within feeding areas may be related to the relative high disturbance levels of these areas. From the biotic indicators that show a differential response to organic input in fish earthen ponds, the abundance of Capitella spp. as well as the diversity (Shannon–Wiener and Margalef species richness), evenness (Pielou) and AMBI indices seem to be the best indicators to be used in monitoring studies in similar systems. Managers should pay particular attention when Capitella spp. taxa are observed within the feeding areas. Nevertheless, manipulative experiments are needed in order to test the dominance levels of Capitella spp. and the values of those indices that are of concern.

Various enzymes have been successfully localized in whole specimens of several groups of marine animals up to 5 mm body thickness. With certain exceptions the animals are fixed for a short time and then incubated in media modified from those designed for sections. After incubation the specimens are stored in fixative or buffer for later serial sectioning back at the laboratory.