The stomach contents of two Cuvier's beaked whales (Ziphius cavirostris), male and female, stranded on the western Mediterranean coast were analysed. Food consisted exclusively of hard cephalopod remains. The character of this teuthophagous diet agrees with the offshore and deep diving behaviour of Z. cavirostris.

The soft-bottom zoobenthic community structure of Izmir Bay was examined seasonally at eight stations (depth-range: 19–67 m) in 2009. A total of 427 species were found. Polychaeta had the highest number of species (50% of total species) and individuals (75%), whereas Echinodermata possessed the highest biomass (47%). The number of species varied from 3 to 79 (0.1 m−2), the density from 60 to 5360 ind.m−2, and the biomass from 1 to 530 g.m−2. The most numerically dominant species were the polychaetes Aricidea claudiae, Streblospio gynobranchiata, Levinsenia demiri and Sternaspis scutata. The distribution of zoobenthos was strongly related to spatial differences in total organic carbon, sediment texture and depth among different regions of the bay rather than temporal differences among seasons. However, significant seasonal variability in community structure (mainly differences in the relative abundance of species) was present. The inner region of the bay can be classified as ‘poor’ or ‘bad’ based on the results of biotic indices (H′, AMBI, m-AMBI and BENTIX). Among biotic indices, only H′ and m-AMBI appeared to be capable of explaining the bay's benthic quality status. Thirteen alien species were also found. Streblospio gynobranchiata, Prionospio pulchra, Pseudopolydora paucibranchiata and Polydora cornuta formed dense populations in the inner most polluted part of the bay and are considered to be new pollution indicator species in the eastern Mediterranean Sea.

Little is known of the mechanisms whereby trematode parasites of fish gills attach themselves to their hosts. The adhesive apparatus consists of a posterior set of suckers or clamps supported by skeletal bars (sclerites) whose arrangement varies considerably in the different species. Yet though the pattern of these sclerites forms the main basis for the classification of the 200 or so species of the Diclidophoroidea into its six families, the only attempts to describe the mechanism of attachment of these parasites to their hosts appear to be those of Cerfontaine (1896), who described the attachment of Diclidophora denticulata to the gills of Gadus viretis, and of Sproston (1945a) and Llewellyn (1956a), both of whom described the attachment of Kuhnia scombri to the gills of Scomber scombrus. In the present paper the mechanism by which Plectanocotyle gurnardi (v. Ben. & Hesse) adheres to its hosts Trigla cuculus L., and T. lineata Gmelin will be described.

The State of Santa Catarina in southern Brazil is the most important Brazilian producer region. The Pacific oysters Crassostrea gigas and the brown mussels Perna perna are the main species currently produced. The occurrence and impact of parasites on bivalves from natural or culture populations from Brazil are still poorly studied. This work describes several diseases, parasites and commensals from four edible bivalve species, from cultured and exploited stocks, from five sites at Santa Catarina State. Unspecific histopathological symptoms of stress, parasites and commensals were found, including viral gametocytic hypertrophy and rickettsia-like organisms with very low prevalences; the protozoan Nematopsis sp. with high prevalence and, ovarian parasites with low prevalences; and, diverse metazoans, such as turbellarian, sporocysts and metacercariae of trematodes, metacestoda larvae and spionid polychaete. Ray's fluid thioglycollate medium assays for detection of Perkinsus spp. did not detect any infected bivalves. Polymerase chain reaction assays for Marteiliodies chungmuensis in oysters with ovarian lesions produced negative results.

1. The relation between the dry weight of the decalcified barnacle and its shell volume has been determined in its relation to age, season and tidal level, at Port Erin, with the following results: (a) In immature barnacles, tissue growth continues throughout the year, but is most rapid in the spring and autumn, (b) In mature barnacles which produce a considerable amount of larvæ there is a heavy drop in tissue weight during the summer period of high temperature, and another slighter drop during the winter, the latter being apparently associated with the presence of developing larvæ in the mantle cavity.

2. Gonad samples were examined seasonally. At low levels on the shore the barnacles mature in their first year. Above this level they do not commence to mature until over a year old. The sequence of changes in the gonads is described. A condition of senility is found in many of the largest high-water barnacles.

3. The naupliar content was estimated in relation to size and tidal level, counts of up to 13,000 larvæ per individual being obtained. The dry weight of a fully developed nauplius was determined to be 7·5×10-4 mgm.

The colour of the chromoplasts in the Chrysophyceae varies from a greenish yellow to a golden brown. Klebs (1892) described this colour as being due to a special pigment which he called ‘chrysochrom’. Gaidukov (1900) made an acetone extract of a dense bloom of Chromulina rosanoffii (Woronin, 1880) Biitschli filtered from the tanks in the cold glasshouses of the Botanic Gardens in St Petersburg. He found a water soluble pigment which he called ‘phycochrysin’ together with ‘chrysochlorophyll’ and ‘chrysoxanthophyll’. Most authors have since questioned the existence of special pigments in the Chrysophyceae (Fritsch, 1937; Smith, 1938). Carter, Heilbron & Lythgoe (1939) analysed extracts of an incrustation of Apistonema carteri, Thallochrysis litoralis and Gleochrysis maritima (identified by F. E. Fritsch) found on the chalk cliffs at Folkestone, and identified β-carotene, fucoxanthin and lutein, using calcium carbonate as adsorbent in their analysis. Heilbron (1942) later drew attention to the fact that these pigments are present in the Bacillariophyceae but not in the Xanthophyceae, throwing doubt on Pascher's view of the close relationship of all three groups. We now know that it is not lutein but diadinoxanthin that is present in the Bacillariophyceae (Strain, Manning & Hardin, 1944). Seybold, Egle & Hülsbruch (1941) then showed that the chlorophyll present in Hydrurus foetidus and Chromulina rosanoffii was chlorophyll a, apparently without other chlorophylls. Seybold (1941) has commented further on the singular occurrence. and implications of chlorophyll a alone, and this has been recently discussed by Allen (1958). In recent years our knowledge of the pigments of the algae has been greatly advanced by Strain and his colleagues (Strain, 1958) but, while the pigments of the Xanthophyceae and Bacillariophyceae have been examined with the improved techniques now available(Pace, 1941; Strain, Manning & Hardin, 1943, 1944; Strain, 1958), those of the Chrysophyceae have not.

INTRODUCTION

Ophiacantha bidentata (Retzius) is a widespread arctic-boreal ophiuroid with a circumpolar distribution in the shallow waters of the Arctic seas and penetrating into the deep sea of the.North Atlantic and North Pacific (Mortensen, 1927, 1933a; D'yakonov, 1954). Early observations of this species were confined to defining zoogeo-graphical and taxonomic criteria including the separation of deep water specimens as the variety fraterna (Farran, 1912; Grieg, 1921; Mortensen, 1933a). Mortensen (1910) and Thorson (1936, pp. 18–26) noted the large eggs (o.8 mm diameter) in specimens from Greenland and Thorson (1936) proposed that this species had ‘big eggs rich in yolk, shed directly into the sea. Much reduced larval stage or direct development’. This evidence is supported by observations of O. bidentata from the White and Barents Seas (Semenova, Mileikovsky & Nesis, 1964; Kaufman, 1974)..

Temporal patterns in metazoan parasite community diversity of Crassostrea gigas, (Lamellibranchia: Ostreidae) were studied in the Exe Estuary at monthly intervals over one year and in relation to host age-classes. A total of four metazoan species was found to parasitize C. gigas in the Exe Estuary: the turbellarian Paravortex sp., cercaria Lepocreadiidae, metacercariae of Renicola roscovita and the copepod Mytilicola intestinalis. Only R. roscovita and M. intestinalis were present in all months throughout the year and in all host age-classes. Analysis of the metazoan parasite community at individual host level revealed little variation in community structure with respect to season or host age, as only a slight increase in diversity values was observed during the summer months. However, community diversity does vary from year to year, as shown by comparison between host age group samples in three consecutive years. None of the parasites are specialist to oysters but all appear to be widespread and abundant parasite of other lamellibranch species.

Schistomysis ornata (G. O. Sars) occurs in the deeper regions of the Firth of Clyde and in many of the lochs of the west coast of Scotland. It has been caught in Loch Fyne at depths as great as 175 m but is more common living above a muddy bottom in depths between 50 and 100 m. It is rarely caught in large numbers but as many as 100 individuals have been caught per haul in the western arm of the Kyles of Bute, Firth of Clyde and in Loch Etive, Argyll. It is associated with populations of Erythrops serrata (G. O. Sars) and Leptomysisgracilis (G.O. Sars) in the Clyde (Mauchline, 1968,1969) and with populations of Pareuchaeta norvegica (Boeck) and Sagitta elegans Verrill in Loch Etive.

During resting spore formation Ditylum loses the cell sap and the volume of the resulting resting spore is one-third to one-twentieth of the cell volume.

Ditylum plasmolyses in 3·5–I.7% NaCl solutions, and in a few seconds the protoplast is reduced to the size and structure of a resting spore. In 0·5% NaCl there also occurs a considerable reduction in volume. The plasmolysed cells recover completely when removed into sea water. Rapid plasmolysis was also observed in isotonic and hypotonic dextrose and sucrose solutions and in solutions of CaCl2.

The growth of Chlamys opercularis from three sites in the Firth of Clyde has been studied. A relationship exists between the different dimensions of the shell, but, because growth is allometric, these relationships do not remain constant throughout the life of the animal. In contrast to the rectilinear relationship between the shell dimensions, the cavity volume and the weight of the shell and the weight of the soft tissues increases exponentially with increasing shell height. The growth rings on the shell of Chlamys were shown to be truly annual and are deposited primarily during the period from April to June, providing a convenient and reasonably accurate technique for assessing the age of individual animals. The size range of the height of the first ring was quite large, with a bimodal frequency distribution. The bimodality is lost in the second and subsequent years due to differential rates of growth between large and small first-year animals. The rate of growth of Chlamys from the Clyde Sea area was determined from values for the mean height of each annual ring, and has been compared to the rates shown by Chlamys from other sites around the British Isles.

INTRODUCTION

Work on pumping and filtration rates of bivalve molluscs was initially concerned with the physiological concept of pumping water through the mantle cavity. Comprehensive reviews are given by Winter (1970) and Ali (1971). The methods are of two kinds; direct, in which the flow of exhaled water itself is measured, and indirect, in which the rate of clearance of food particles is used to calculate water flow through the gills.

There is a disadvantage in the indirect method when used to calculate volumes of water pumped because it involves the assumption that a fixed percentage (often 100% with large particles) of the particulate matter passing through the gill system is retained. Pumping rate is thus estimated as a function of the particle collecting properties of the latero-frontal cirri, whereas the water current is produced by the lateral cilia. Although the structure of the latero-frontal cirri is now well documented (Moore, 1971), their efficiency in particle retention can alter under certain conditions (Dral, 1967). There is need, therefore, for direct measurement of the quantity of water pumped. Recent advances in the understanding of branchial innervation and the control of lateral ciliary activity also reinforce this point (Aiello, 1960, 1962, 1970; Paparo, 1972, 1973).

The constant level chamber for direct measurement of pumping rate was devised by Galtsoff (1926), to ensure that separation of the exhalant water current from the bivalve was not interfered with by pressure differences produced by the process of separation. The apparatus has been used in various forms by Galtsoff (1926, 1928, 1946), Nelson (1935, 1936), Collier & Ray (1948), Loosanoff & Engle (1947), Loosanoff & Nomejko (1946) and more recently by Drinnan (1964) and Davids (1964).

The nature and the quantity of run-off into coastal waters will to a large extent influence the occurrence and distribution of a number of chemical components such as nutrient salts, organic matter and trace metals in these waters. In open coastal environments the run-off is usually quickly dispersed and diluted so that little of it remains at concentrated levels in the vicinity of the discharge point. On the other hand, if such discharge is made into closed or confined waters, the rate of dispersal will depend on the circulation pattern and the rate of flushing of the run-off. Thus in some areas where the circulation is restricted, a build up of compounds may occur which, depending on the run-off composition, may have a marked effect on the ecology of these waters. The situation may be further aggravated if the run-off includes large quantities of industrial and domestic waste.

Interest has developed recently in the biochemical composition of zooplankton, particularly in relation to seasonal changes. An earlier study (Raymont, Srinivasagam & Raymont, 1971b) on deep frozen Antarctic krill, Euphausia superba, collected over approximately 5 weeks in December/January 1968/69 suggested that protein was the main constituent and lipid much more variable. Despite the variability the mean lipid content during January was distinctly higher than in the previous month, thus supporting the findings of Kryuchkova & Makarov (1969) that lipid content of krill tends to increase as the summer advances. However, collections of material from the Antarctic have tended to be limited both in location and season while methods of preservation have varied. It seemed desirable to follow changes in the biochemical composition of krill collected from a somewhat wider area and over a longer period. Moreover, the more extensive material gave opportunity for a more detailed examination of specific fractions, such as the amino acids of Euphausia superba. Preliminary investigations (Srinivasagam, Raymont, Moodie & Raymont, 1971) on the amino acid composition of protein hydrolysates showed good agreement with the results of some other authors. However, the findings of Burkholder, Mandelli & Centeno (1967) and especially of Moiseev (1970) showed certain differences.

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.

When studying the seasonal changes in the algal plankton in relation to the supply of the constituents necessary for their growth, one is led to seek the source of the silica used to form the valves of the diatoms and to consider whether lack of silica might be a factor limiting their multiplication.

The metazoan parasites of 101 lesser-spotted dogfish Scyliorhinus canicula from locations off the coast of England (Plymouth and the eastern Solent) and Wales (Cardigan Bay) were surveyed and assessed for their potential as stock discrimination tools.  A total of ten parasite species was found using a relatively rapid host examination technique suitable for non-parasitologists. On the basis of established criteria, larval anisakid nematodes and the copepod Lernaeopoda galei were selected as being potentially useful as stock discrimination tools. The monogeneans Leptocotyle minor and Hexabothrium appendiculatum may be suitable as markers following further investigation of their response to handling stress.

The magnitude and sustainability of incidental catches of marine mammals in fisheries was investigated in Sabah and Sarawak, East Malaysia, using a combination of interview surveys and observer trips on fishing boats. These fisheries involve around 15,000 registered fishing boats and generate annual landings of around 350,000 tonnes. Between March 1997 and December 2004, we interviewed fishermen working on 753 and 358 boats in Sabah and Sarawak, respectively, who were employing trawl nets, purse seines, gillnets and fish stakes. They were asked questions about sightings of marine mammals and interactions with fishing. We also followed 36 trawl and 10 purse seine fishing trips in Sabah between June 2003 and December 2004. Fishing was conducted in coastal waters and total annual catches by each method and region were estimated. Incidental catches of marine mammals were reported by fishermen from 310 (41%) and 99 (28%) fishing boats in Sabah and Sarawak, respectively. Gill-netters, trawlers and fish stakes were reported to catch cetaceans and dugongs, while purse seiners caught only cetaceans. The Irrawaddy dolphin, bottlenose dolphin, spinner dolphin, pantropical spotted dolphin, Indo-Pacific humpback dolphin and finless porpoise are the cetacean species known to be taken. Overall, the magnitude of incidental catches of marine mammals is greatest in gillnets. No marine mammal catches were seen during observer trips. Interview results suggest annual by-catches of 306 (95% CI = 250–369) cetaceans and 479 (95% CI = 434–528) dugongs in Sabah. Estimates for Sarawak were 221 (95% CI = 189–258) cetaceans per year and 14 (95% CI = 2–30) dugongs. These results suggest that by-catch rates, particularly in gillnets, may be unsustainably high. A dedicated monitoring and educational programme, together with the establishment of Marine Protected Areas, is urgently needed to minimize the threat.

Gametogenesis and reproductive periodicity of the solitary scleractinians Flabellum alabastrum (from the Rockall Trough) and F. angulare (from the Porcupine Seabight) were investigated. Samples were collected between depths from 1370 to 2190 m for F. alabastrum and 2412 to 2467 m for F. angulare. Both species showed gonochorism with a 1:1 sex-ratio and broadcast spawning of gametes is inferred from the lack of brooded planulae. Oocyte sizes were large in both species (925 μm in F. alabastrum and 1015 μm in F. angulare), suggesting lecithotrophic larval development. Fecundity and periodicity of oocyte development differed between the two species. Flabellum alabastrum produced a maximum of 2800 oocytes per polyp quasi-continuously, whereas the deeper species F. angulare produced a maximum of 550 oocytes per polyp either seasonally or periodically. Both species showed size-dependent fecundity. The data show a decrease in oocyte size and fecundity with depth, in concordance with other deep-water scleractinian species.

The life cycles of Clytia linearis and Clytia noliformis, two common campanulariids previously known solely from their polyp and young medusa stages, were investigated. Adult medusae of C. linearis have a bell diameter of 2·5–3·6 mm, and up to 29 tentacles. The bell is almost flat when relaxed and C-type microbasic mastigophore nematocysts form a cluster at the tip of the tentacles. Mature medusae of C. noliformis have a more hemispherical, saucer-shaped bell (3·5–4·5 mm in diameter), up to 16 tentacles, and no diagnostic nematocysts. Polyps of both species also differ in morphology, colour, and cnidome, and a possible resting structure is described for C. linearis. The relevance of characters from the perisarc and hydranths for taxonomy within the Campanulariidae is also evaluated, and whether the size of nematocysts is variable or not, and therefore appropriate for species identification.