Acoustic surveys can have several advantages over visual methods in surveys of cetaceans, although verification is required that novel techniques are effective. The T-POD is an autonomous acoustic data logger with inbuilt filters that can be set to match the click characteristics of the target species. We tested the performance of the T-POD for detecting Hector's dolphins at Flea Bay, Banks Peninsula, New Zealand. Simultaneous visual surveys were conducted from a hillside overlooking the bay, with distances between the T-POD and dolphins measured using a theodolite. Wideband sound recordings confirmed that T-POD detections were echolocation clicks made by Hector's dolphins. Detection probability and click train detection rate decreased with increasing distance, with no detections made beyond 500 m. By fitting detection functions to the probability of detection versus distance we showed that the T-POD effectively detected all dolphin groups within a radius of 198–239 m, depending on the click train categories utilized. The T-POD shows considerable promise as a tool for passive acoustic surveys of Hector's dolphins, with possible applications in studies of distribution, habitat use and echolocation behaviour.

Examination of the intertidal distributions of isozyme and pedal colour phenotypes of Actinia equina L. has shown that anemones displaying column coloration ranging from red to brown, are divisible into three, ecologically distinct forms in Britain, which we currently interpret as being morphs of a single species. These are termed the upper (U), mid (M) and lower (L) shore morphs, which are relatively most abundant on the upper mid, lower mid and low shores, respectively; not all morphs are represented on some shores. The U, M and L morphs may be separated on the basis of their hexokinase and malate dehydrogenase phenotypes. The U morph is homozygous slow and fast respectively, the L morph is slow and fast respectively whilst the M morph is heterozygous at both loci. Data on linkage of pedal disc colour and alleles at a tetrazolium oxidase locus, and of an association between alleles at the hexokinase locus and those at an esterase locus, are given.

Fish eggs can be divided into three main groups: marine pelagic eggs which float of their own accord, marine demersal, and freshwater demersal eggs. The embryological development of freshwater teleosts follows an accepted pattern, demonstrated by morphologists during the nineteenth century. Marine embryos, both pelagic and demersal, do not conform in all respects to this pattern, and misunderstandings have frequently arisen by lack of attention to known structural differences between the three groups. Mclntosh & Prince (1890), in their comprehensive review offish development, emphasized some outstanding anomalies in pelagic structure, but gave no adequate explanation of their occurrence.

The cyanobacteriosponge Terpios hoshinota is expanding its range across the Indo-Pacific. This species can have massive outbreaks on coral reefs, actively kill corals it overgrows and affect the entire benthic community. Although it has received much attention on the post-outbreak follow-up, little is known about its ecology, habitat preferences, and the possible environmental triggers that cause its outbreaks. We present a baseline study in the Spermonde Archipelago, Indonesia, where T. hoshinota was first observed in 2012. We surveyed 27 reefs and recorded patches between 14 and 217 cm2, at four reef sites (~15% cover). The sponge was found on both mid-shelf and outer shelf reefs but not close to the coast and the city of Makassar. Differences in benthic community structure, as well as spatial variables relating to the on-to-offshore gradient in the Spermonde archipelago, neither constrained nor promoted its expansion. Patches of the sponge were mostly overgrowing branching corals, belonging to Acroporidae species. Genetic variation within T. hoshinota was studied by sequencing partitions of the mitochondrial CO1 and nuclear ribosomal 28S gene. Two haplotypes were found within the Spermonde archipelago, which differed from the CO1 sequence in GenBank. The present study provides an indication of habitat preferences of T. hoshinota in non-outbreak conditions, although it is still unclear which environmental conditions may lead to the onset of its outbreaks.

In this study we present results on epibionts on Zygochlamys patagonica from material collected during monitoring cruises in different areas in the Argentine Sea. We update the checklist of epibionts increasing the number of taxa from 19 to 41 and considering two species closely associated with the shells. The demosponge Iophon proximum was the most frequent and abundant epibiont (% presence and coverage). Polydora sp. was registered as a parasite of Z. patagonica in shells from the Beagle Channel, but it did not infest scallops from the commercial beds. Zygochlamys patagonica shells constitute conspicuous hard substrate available for the settlement of sessile organisms. This fact leads to an increased benthic richness in the continental soft-bottom areas of the Argentine Sea, where scallop beds are located.

Ctenophores are important members of planktonic communities that are often abundant in dysaerobic environments. Previous studies have shown that ctenophores are not adversely affected by extended periods of hypoxia. The three species used in this study, Pleurobrachia bachei, Bolinopsis infundibulum, and Mnemiopsis leidyi, were all able to oxyregulate to very low partial pressures of oxygen (PO2s). These species were found to have mean critical oxygen tensions of 7.7, 10.6, and 7.2 hPa respectively. In general, ctenophores are better oxyregulators than medusae and many species of shrimps, fish and squid. Intragel oxygen was measured using a fibre optic oxygen optode. All these ctenophores have intragel subsurface [O2]s of 5–10% below that of the surrounding seawater. Intragel oxygen measurements of P. bachei showed a gradient of decreasing PO2 from surface tissues to the gut. Specimens of P. bachei over 14 mm in diameter had anaerobic guts. Survival times in anoxia ranged from 0 h for M. leidyi to up to 6 h for P. bachei. Ctenophores rely on aerobic metabolism to tolerate hypoxia.

Reproduction by the moon jelly, Aurelia labiata, was observed in a small bay on the west coast of Canada. The bay is located in an area isolated from human contact except in the summer, is sheltered from wind and wave action by mountain ridges, and has limited tidal flushing due to a gravel bar at the entrance that dries at lower low water. Planulae appeared in brood sacs beginning in October and November. The planulae were shed by the end of March and ephyrae emerged in June. Juvenile medusae were estimated to constitute about 30—40% of medusae in the bay in each of the two years of this study. Medusae remained in the bay throughout the year. There was no major visible mortality in the adult population during the two year observation period. Medusae appear to be lost from the bay as a result of tidal flushing. It is argued that in Roscoe Bay Aurelia labiata medusae live for more than one year and that up to 40% of the adult medusae may be two years of age or older.

During a study of the fauna of the level sea-bottom off Plymouth on which a report has already appeared in this Journal (Ford, 1923), the samples taken in the Petersen bottom-sampler and in the conical dredge were preserved in alcohol and retained. A subsequent re-examination of the accumulated material has provided information on the growth of a number of lamellibranchs, which forms the subject matter of the present paper. As the samples were collected according to a programme arranged expressly to determine the animal communities represented, it was not to be expected that they would yield complete data on the growth of a particular species, but the results are interesting and useful when considered in their relation to the food supply of our food-fishes. I must again acknowledge my indebtedness to Mr. R. Winckworth of Brighton for his continued assistance in identification and measurement of specimens. Such expert confirmation of identification was naturally desirable’ in dealing with the growth of species from the earliest stages. Throughout the paper the term “length” is adopted, meaning the greatest antero-posterior dimension of the shell. This term was used by Weymouth (1923) who gave a figure on page 20 which shows clearly the measurement to which the term is applied. I have also used “length” as a measure of growth-rings on the surface of shells. In Fig. 7 on Plate III, I2 is the length of the second ring on a shell of Spisula solida. Thirty-three genera of lamellibranchs are represented in the material of which all but nine appear among the records compiled by Todd (1907) and Blegvad (1917) of the contents of the stomachs of fishes which include dab, flounder, long-rough dab, plaice, sole, cod, haddock, whiting, cat-fish, viviparous blenny, fresh-water eel, herring and mackerel.

1. A simple colorimetric method for plotting the dissociation curve of haemocyanin is indicated. The limits of error are within 5 per cent. The simplicity of the method commends it for laboratory class work.

2. The effect of hydrogen ion concentration on the dissociation of the hsemocyanins of the crustacean Palinurus and the pulmonate Helix have been compared. In the snail change of hydrogen ion concentration over a wide range was not found to affect the dissociation of the hsemocyanin: in 'the crustacean there is a marked effect similar to that seen in the dissociation of hæmoglobin.

3. The similarity of crustacean hsemocyanin to haemoglobin is also seen in that increasing temperature depresses the dissociation curve. The effects of certain salts upon haemocyanin. have also been recorded.

Age, growth and maturation of Loligo vulgaris were studied by examination of growth increments within statoliths of 294 specimens (mantle length, ML, ranging from 31 to 498 mm) caught on the west Saharan shelf between 1985 and 1988. Maximum age was 335 d (290 mm ML) for females, and 396 d (498 mm ML) for males. Growth rates varied considerably among individuals with a greater range in males. Sexual dimorphism in length was apparent after about 210 d. Males and females diverged considerably in weight, with males reaching a greater weight after about 180 d. Growth in length between 124 and 396 d was best described by a power function, while growth in weight was best described by the Gompertz function. Males started maturing at 180–210 d and mature males ranged in age between 250 and 396 d; while females started maturing at 240–270 d and mature females ranged between 285 and 335 d. Loligo vulgaris hatched throughout the year with two distinct peaks; in winter (December - early March) and summer (June-July). The life cycle of L. vulgaris populations on the west Saharan shelf lasts ~1 y, with large males (>450 mm ML) living slightly longer.

Viruses are hypothesized to cause enhanced diversity in bacterial communities by regulating the outcome of intertaxon competition. However, concomitant documentation of viral and bacterial assemblage composition in oligotrophic waters are rare, particularly in situ over time, and there is almost no information on the temporal variability in virioplankton assemblage composition in oligotrophic water masses. Assemblage composition of viruses (via pulsed-field gel electrophoresis, PFGE) and bacteria (via automated rRNA intergenic spacer analysis, ARISA) was compared during surface lagrangian drifter deployments in the oligotrophic Gulf of Mexico during summer 2001, 2002, and 2003. In vertical profile, viruses and bacteria both had maximum abundances in surface waters, which decreased with depth; however, the richness of their assemblages was not significantly different between depths, suggesting independence of biomass and diversity. Viral assemblages changed rapidly (0.17–0.32 Jaccard index d−1), which was similar to the rate of change in bacterial assemblages reported in surface waters. Patterns of viral and bacterial assemblage composition were significantly related (P<0.001, r=0.58 between node ranks), and both assemblages clustered primarily by year and then by depth. These cultivation-independent observations demonstrate relationships between viral and bacterial assemblages, which are dynamic in patches of open ocean water. Even at the relatively low phylogenetic resolution of the ARISA and PFGE methods, the results support the idea that viruses may influence the species composition of host assemblages.

Landmark-based geometric morphometric methods were used to test which chela is most suitable to use in population differentiation of brachyuran crabs. Two species were analysed: Pachygrapsus marmoratus, a homochelous species, and Carcinus maenas, a heterochelous species. Variance analysis of shape variables and of each chela was calculated to determine which claw presents less variation within populations. The results showed that the right chela of P. marmoratus is more appropriate to use when the goal is to differentiate populations. In C. maenas, the males major chela and females right chela are more suitable to use, probably due to its heterochely. To test these results, specimens from different geographical locations were compared. Pachygrapsus marmoratus populations presented significant differences in manus shape, and C. maenas populations had differences in polex size and shape. Differences in carapace shape were also encountered between populations of both species. This phenotypic variation was not corroborated with genetic data, which were obtained using the mitochondrial DNA gene cytochrome oxidase I as a marker. These opposite results suggest that environmental factors, such as diet and parasitism, can be determining shape differentiation.

The reproductive biology of the pelagic thresher shark Alopias pelagicus, was analysed based on 241 individuals (101 males and 140 females). Samples were collected from April 2005 to February 2006, from the artisanal fishery in Manta, Ecuador. Males ranged from 68 to 183 cm precaudal length (PL); females ranged from 70 to 180 cm PL. In embryos, sexual proportion was 1F:1M; while in adults the proportion was 1.4F:1M, which suggests sexual segregation in maturing individuals. We showed differences in the development of reproductive structures according to the reproductive condition, and in males the size at maturity occurs at 144.3 cm PL and in females at 151.4 cm PL. We recorded 33 pregnant females that presented one embryo in each uterus in different developmental stages. The results of this study provide information on reproduction of the species that will help to establish an appropriate fisheries management.

The haemogram (blood cells concentration, number and proportions of haemocyte morphotypes) of the common periwinkle, Littorina littorea, was studied in terms of its individual variations and seasonal dynamics. No granular blood cells were found. Three morphotypes of hyalinocytes were observed in the haemolymph of L. littorea and are described at both light and electron microscopy levels: juvenile round cells, intermediate cells and large mature haemocytes. The nucleoplasmic ratio, nucleus shape and location, number and size of glycogen deposits were the main characteristics used to discriminate between the haemocyte morphotypes. The enzyme cytochemistry and lectin binding studies did not identify additional haemocyte morphotypes. The experiments on BrdU incorporation showed that haemocyte population renewal occurred due to the proliferation of only one cell type, namely blast cells, which were morphologically similar to juvenile round cells. The three-month dynamics of the periwinkle haemogram and haemoblast proliferative activity are described. The blood cell concentration reached maximum values twice per summer season—in June and August, with the haemocyte proliferation activity being the highest in June. The percentage of mature haemocytes increased during the season, simultaneously intermediate cells demonstrated a decrease in number by the end of summer, with the population of juvenile cells being nearby constant. The method of haemogram analysis is positioned as a powerful technique having good potential in eco-toxicological, parasitological and immunobiological studies.

Mortality resulting from fishing of scallops (Pecten maximus L.) can be divided into the loss caused by their removal for marketing and the indirect damage inflicted during the operation both by the dredges on the sea bed and the rough handling of undersized discards on board the boat (Medcof & Bourne, 1964; Caddy, 1968). Direct fishing mortality is easily measured if both the relevant biological information and catch data are available. Indirect fishing mortality is more difficult to estimate. Deaths due to damage by the dredges cannot easily be distinguished from natural deaths, and although damage to discards can be assessed before they are thrown back (Medcof & Bourne, 1964), the correlation between such damage and subsequent mortality is almost impossible to obtain in the field.

The metazoan parasite community of Cerastoderma edule was studied in the southern geographical range of the host (the coastal lagoon Merja Zerga, Morocco). A total of 11 metazoan species was found in cockles. Nine of these were trematodes using cockles as either first intermediate host (three species) or second intermediate host (six species). In addition, two other endo-metazoan species (Pinnotheres pisum and Paravortex cardii) were recorded from cockles in the studied lagoon. All the observed metazoans in cockles from Merja Zerga have previously been recorded at sites north of Africa.

Up to 10% of the cockles in the studied size-groups were first intermediate hosts to castrating parasites (Gymnophallus choledochus, Labratrema minimus and Monorchis parvus). Among trematodes having metacercariae in cockles (second intermediate host) Meiogymnophallus minutus was the most widespread as it was observed in all cockles from all the examined habitats in the lagoon and it occurred in record high intensities. Different sub-communities of the trematode fauna using cockles as second intermediate host could be identified (subtidal vs intertidal associations).

The richness and species composition of the macroparasite community in cockles from Morocco are discussed in relation to patterns seen in cockles from other sites along their geographical range. Migratory fish and waterbirds (final hosts) are generally responsible for the large scale spread (latitudinal spread) of trematodes. However, the distributional patterns of involved intermediate hosts in the life-cycles of the different trematode species in cockles are determining the richness and species composition patterns seen in cockles at shallow water sites along the east Atlantic shoreline.

A total of 618 cephalopods comprising 29 identified species and 98 young unidentified larvae were collected at 30° N 23° W in opening–closing rectangular midwater trawls (RMT combination net), an Isaacs Kidd midwater trawl equipped with an openingclosing bucket and a British Columbia midwater trawl. Discrete horizons were fished between the surface and 2000 m and day and night vertical distribution for the more common species is described. Material is sufficiently abundant to draw tentative conclusions on the vertical distributions of 16 species. These show a wide variety of migratory and non-migratory behaviour including diel migration, ontogenetic migration and static distribution at various depths and over various depth ranges.

Our published work has shown that the northern euphausiids, Meganyctiphanes norvegica, Thysanoessa raschii and T. inermis, contain much higher concentrations of vitamin A than we have found in any other marine Crustacea (Kon & Thompson, 1949a; Batham, Fisher, Henry, Kon & Thompson, 1951; Fisher, Kon & Thompson, 1952, 1953, 1954). In the antarctic species, Euphausia superba, the concentration of vitamin A in samples taken from the alimentary canals of baleen whales (Thompson, Ganguly & Kon, 1949; Kon & Thompson, 1949b) was similar to that found in Meganyctiphanes norvegica from the gut of arctic baleen whales (Fisher et al., 1952), but both were very much lower than in free-swimming M. norvegica. No corresponding free-swimming specimens of Euphausia superba had been analysed.

The organization of the alimentary canal of fishes differs greatly between species of different dietary habit, but is not well understood. The vagus and sympathetic systems are very different in elasmobranchs and teleosts, but there has been little work on the corresponding physiology and pharmacology. The digestive system of elasmobranchs has unusual features connected with the fact that the absorbtive surface is provided by the spiral intestine (Fig. 1). This is a short fat tube whose surface is greatly increased by the presence of a coiled fold, the spiral valve. This arrangement provides a large area for absorbtion, neatly packed, but it leaves only a narrow lumen, so that no large particles can pass along the spiral intestine. Presumably it is in connexion with this condition that the stomach is divided into two parts. The cardiac division is a large sac into which the prey is received whole, its wall is very glandular and much breakdown of the food proceeds there (Hogben, 1967). The pyloric division is a narrower tube, leading from the hind end of the cardiac part to the pylorus.

Over a four year period, gonad index, examination of gonad tubules, and histology were used to study the reproduction in the sea cucumber Actinopyga mauritiana. This species reproduced annually during the warmer months of the year in Solomon Islands. This annual reproductive cycle progressed through five maturity stages: recovery, growing, mature, partly-spawned and spent. The recovery stage (March–May) was marked by initiation of gametogenesis and coincided with decreasing day length. The growing stage (June–September) was characterized by development of gametes through to the mature stage (October–December). Spawning occurred October through December and coincided with increased water temperature and day length. Spent gonads (January–March) contained a few unspawned gametes or completely lacked gametes. Although A. mauritiana had annual reproduction, individuals lacking or having indeterminate gonads were present year-round. Macroscopic examination of gonad tubules after biopsy provides a practical tool for assessing maturity condition of broodstock in the field during the reproductive season.