Despite the importance of early life-history processes in regulating population assemblages of benthic invertebrates at hydrothermal vents, they remain poorly understood, mainly because of the inaccessibility of these habitats. Vestimentiferan tubeworms provide an excellent system to study settlement in these habitats; they inhabit tubes that remain intact for some period even after the occupants die, and thus provide a proxy for rates of settlement and post-settlement mortality. In 2007, we collected rocks supporting populations of Lamellibrachia sp. using a TV-grab, from Mussel Ridge hydrothermal vent field on Monowai Volcanic Complex, at the Tonga–Kermadec arc. Twenty-two discrete patches of similarly sized individuals and of discrete length–frequency distributions were identified and quantified. Mean length of individual tubeworms ranged from <0.5 to 6.38 cm, and abundance per patch ranged from 6.8 to 108 ind cm−2. Post-settlement mortality was ~5%. These results suggest that gregarious settlement of pulses of larvae is likely occurring by Lamellibrachia sp., a process that has not yet been described in deep-sea hydrothermal vent tubeworms. The abundance of adult tubeworms on Monowai was low, and allochthonous larval supply from neighbouring seamounts unlikely. Consequently, gregarious settlement can increase the probability of maintenance and expansion of the existing populations.

Deep-water shrimps are recognized as non-conventional culinary delicacies owing to the presence of high-quality polyunsaturated fatty acids, even though they remain one of the predominantly unexplored marine fishery resources. In this study, variation of fatty acid profiles of Aristeus alcocki, Solenocera choprai, Heterocarpus chani and Plesionika quasigrandis, caught along the south-west coast of India (Arabian Sea) during the months spanning from September 2018–April 2019, were compared. Among the deep-water shrimps studied, A. alcocki contained a greater amount of n-3 fatty acids, such as docosahexaenoic and eicosapentaenoic acid along with optimal n-3/n-6 polyunsaturated fatty acid ratios beneficial for human nutrition (up to 8 during the winter months) when compared with other shrimps. In general, fatty acid concentrations exhibited variations, particularly with regard to polyunsaturated fatty acids, such as eicosapentaenoic acid and docosahexaenoic acid. These n-3 fatty acids were predominant during December–February of the studied year, but concentrations were noticeably lower during March and April. Females had considerably higher (P < 0.05) C20–22 n-3 fatty acid concentrations along with nutritionally balanced polyunsaturated/saturated fatty acid ratio than males. Results of the two-way multivariate analysis of variance (MANOVA) revealed statistically significant differences in the fatty acid profiles between the species and months. The interaction effects of months with species were also highly significant (Wilk's lambda = 0.000001; F = 187.7, P < 0.0001). Lesser atherogenicity (<3) and thrombogenicity (<0.5) indices coupled with considerably greater n-3/n-6 fatty acid ratios recognized these deep-water species as a possible source of highly nutritional human food.

Diversity of hard corals is investigated on the reefs of two Iranian islands, Qeshm and Larak, located in the Persian Gulf. The corals were sampled and photographed and their percentage cover was estimated by diving in June 2008 and February 2009. Thirty-eight coral species belonging to 20 genera and nine families were identified, of which three species are new records from the Gulf. Coral diversity was higher in Larak Island, and in total, Acroporidae and Faviidae were the most diverse coral families. Acropora (83%) had the highest percentage cover in Larak Island, while the maximum percentage cover in Qeshm Island was for Porites (52.96%). Canonical correspondence analysis distinctly plotted the study sites against environmental variables. Salinity and pH were the most effective variables on the coral diversity, and had positive correlations with the frequency of several species including Pocillopora damicornis, Platygyra acuta and Acanthastrea maxima, while they had negative correlation with another group of other corals, including Plesiastrea devantieri, Acropora downingi and Psammocora digitata (P < 0.01). Water clarity had positive correlations with some coral species, including Cyphastrea serailia and Coscinaraeamonile, and negative correlations with other species such as Leptastrea transversa and Acropora arabensis. Diversity of a number of corals mainly Porites lutea and Cyphastrea chalcidicum had high affinity with the water temperature. The results of this study supported the existence of diversified coral communities in Iranian islands, while showing that their spatial and temporal distribution can be affected by environmental variables.

The morphology and infraciliature of the marine hypotrichous ciliate Holostichanagasakiensisi sp. nov. from the coastal waters of Nagasaki, Japan are described based on living and protargol-impregnated specimens. The new species is characterized by: medium-sized marine Holosticha,in vivo 100–150×30–40 μm with elongated body shape and slightly greyish to reddish cell colour; cortical granules arranged in conspicuously longitudinal rows; 24–32 adoral membranelles; ∼20 midventral cirral pairs and 7–10 transverse cirri; 28–42 left and 25–38 right marginal cirri; constantly 4 frontal cirri and 3 dorsal kineties; 23–63 macronuclear nodules.

1. Details are given of the types of hooks lost in tunny in the North Sea in the summer of 1933.

2. Data are given on the measurements made on thirty-two large migrating fish caught in the North Sea in August and September, 1933.

3. In certain body proportions the tunny measured differ from those in the G4 Group (200 to 260 cm. in length) given by Heldt for fish from Tunis and by Frade for fish from Algarve on the south coast of Portugal, while in some characters they resemble the Tunis fish and in others the Algarve fish, but all the North Sea fish were between 232 and 271 cm. in length.

4. It was found that there was a tendency for fish with short second dorsal fins to have short first dorsal, anal, and caudal fins, and for those with long second dorsals to have these other three fins long.

5. Measurements were made to supply data on the condition of the fish.

As remarked by Stebbing (A History of Recent Crustacea, p. 185): “Upogebia, Leach, 1814, was founded to receive another species discovered by the industrious Montagu, and described by him in 1805 (1808) as Cancer astacus stellatus. … It seems to have escaped the notice of writers subsequent to Leach that the earliest name of this genus was Upogebia, which therefore must be retained in preference to Leach's own alteration of it into Gebia, or Risso's Gebios.”

Rapid shell closure in articulate brachiopods, occurring by a twitch contraction of the the ‘quick’ adductor muscles, is a response to disturbance or to physiological requirements of the organism. The relative simplicity of the closing system permits a detailed analysis of the functional architecture of the mechanism and the underlying principles of skeleto-muscular organization, in terms of (1) basic kinematic properties of the system (speeds and times of closure), (2) hydrodynamic reactions resisting closure, and (3) considerations of muscle physiology and mechanics.

Analyses of shell closure in the brachiopods Terebratulina retusa from the Firth of Lorn, Scotland, and Terebratalia transversa from Puget Sound, USA, reveal (1) shell-closing times of the order of 50 to 70 ms, (2) closing velocities of the order of 3·5 radians s-1, from initial gapes of about 0·05 to 0·2 rad, and (3) muscle moment forces and hydrodynamic reactions with magnitudes of the order of 5 × 10-4 N m (5 g cm). Muscle tensions developed in the ‘quick’ adductor muscle are of the order of 105 N m2, and contraction velocities are of the order of one muscle length per second. Hydrodynamic reactions are a fundamental constraint on the closing mechanism, as determined by the concordance of actual closing events with predictions of a hydrodynamic model.

A new species of Fenestrulina Jullien, 1888, F. asturiasensis sp. nov., is described from the northern coast of the Iberian Peninsula. The main diagnostic features of this species are: four to five oral spines, a completely porous frontal wall and non-stellate frontal pores. These features have allowed the author to differentiate it from F. malusii (Audouin), another species of the genus Fenestrulina Jullien recorded in the same region.

Chromatic polymorphisms in shells may be associated with adaptive characteristics in molluscs. Colouring among Hastula cinerea reveals different patterns in large aggregations of individuals. Although the impacts of temperature are considered critical in the intertidal region, selective effects associated with colouring in H. cinerea shells, in addition to possible physiological consequences, remain an open issue. In this context, H. cinerea is a viable evolutionary model for investigating selective processes related to chromatic polymorphism in shells given its abundance and biological characteristics. Individuals from the same population were classified into three groups according to shell colour: light, reddish and dark. They were then examined with regard to frequency of colour morphs and morphological patterns in each group. Reddish and light-coloured specimens were the most abundant, while those with dark coloration were less common and morphologically distinct from the first two colour morphs. Morphological differences in the anterior region of dark shells, which may be associated with movement ability and lower frequencies in these specimens, suggest possible selective effects on types that are less reflective to light in the intertidal zone.

The study presents dry mass and body measurements of the larval stages of five common barnacle species occurring in mesozooplankton catches of Southampton Water and the central Solent area of the south coast of the UK. Quantitative samples were collected with conventional 120-μm mesh plankton nets. Species-specific regression equations relating carapace width and total length with dry mass were obtained for stage II to stage VI nauplii and cyprids of Austrominius modestus, Amphibalanus improvisus, Balanus crenatus, Semibalanus balanoides and Verruca stroemia. Width–dry mass and length–dry mass regressions obtained in the present study accounted for more than 98% of the variability for naupliar stages, and length–dry mass for 80% of the variability for cyprids. The dry mass of barnacle larvae predicted from carapace width equations determined here differed by only –6% from the measured dry masses of an independent data set, suggesting these first-reported equations of barnacle larvae are useful additions to zooplankton production studies.

The egg of this species has been described and discussed by Professors McIntosh and Prince, by Mr. E. W. L. Holt, and by myself. Raffaele, in his paper in the Mittheilungen of the Naples Station, vol. viii, described the yolk in the ovum of Callionymus festivus as having a peripheral layer of yolk-segments, but no reticulated marking on the surface of the vitelline membrane; while all we English observers have agreed in stating that the egg of Callionymus lyra, our common dragonet, has a reticulated marking on the vitelline membrane, but no yolk-segments. I was, therefore, very much surprised, in examining some eggs of this species from the tow-net this year, to find that there actually was a peripheral layer of yolk-segments, which had hitherto been overlooked.

Using aquaria containing natural sediment, medium-term burrow development was investigated. After initial construction, and over the first month, relatively little burrow development was observed in terms of the number of openings and tunnels created. After an additional six months, however, there was a significant increase in the number of openings and tunnels constructed. In contrast to what might be expected from the number of openings and tunnels created during this period, a significant proportion of the sediment movement was sub-surface and relatively little sediment expulsion occurred. The concentration of nitrite, ammonia and phosphate in the burrow water was generally greater than that of the surface water, whilst the nitrate and sulphate measurements showed no particular pattern. Only the differences in phosphate concentrations were found to be significantly different. These results were indicative of Calocaris macandreae influencing rates of denitrification. This study also provided further evidence of carnivory and caching behaviour in this species.

Purified serum immunoglobulin (Ig) from the flounder has been fragmented by treatment with trypsin at 56°C. The major product of the digestion is a protein which resists further degradation over a two-hour period. This fragment constitutes approximately 40% of the Ig molecule and on fully reducing SDS electrophoresis is composed of a single polypeptide chain of apparent molecular weight 33 kD. This is larger than the light chains and therefore indicates that the fragment is derived only from the heavy chains of the Ig molecule. If this fragment is composed of eight polypeptide chains, consistent with the tetrameric nature of the flounder Ig, then its molecular weight is 264 kD. Although its electrophoretic mobility on 4% non-reducing SDS gels suggests a molecular weight of 180 kD, densitometric data support the 264 kD value. The kinetics of the digestion indicate that the first event is the liberation of a 50 kD fragment which is a dimer of two 25 kD polypeptides and which may be a Fabµ fragment.

Photo-grammetric techniques developed for measuring body length and small scale movement patterns of cetaceans were applied to surface swimming basking sharks off the west coast of Scotland. These methods removed the need for close approaches, reducing the likelihood of disturbing the focal animal. Average swimming speed was calculated from the total path length between shark locations measured at approximately one minute intervals. These average speeds varied from 0.49 to 0.73 ms−1 for tracks of between 30 and 170 minutes' duration. Body length measurements ranged between 2.35 and 6.43 m. For ten sharks where body length and swimming speed were measured there was a significant correlation between body length (L) and swimming speed (V) expressed as V = 0.36L033.

This paper is concerned with the number of eggs in the roes of ripening female plaice, Pleuronectes platessa L., caught off La Rochelle during the winter of 1960–61. The fecundity of plaice has been studied over a number of years in fish collected over a wide area (Bagenal, 1958,19600,6,1962) and the results given in this paper apply to plaice caught as near the southern limit of their distribution as possible. Although plaice have been recorded from farther south (Wimpenny, 1953), La Rochelle is the most southerly port where they can be obtained in sufficient numbers.

The current study examines the reproductive patterns found within four ovoviviparous, brooding periwinkle populations on one shore in the north-east coast of England; the boulder dwelling populations Littorina saxatilis H (upper-shore form with thin shell and large aperture) and L. saxatilis M (mid-shore form with thick shell and small aperture), and the barnacle-dwelling L. saxatilis B (small form similar in morphology to L. saxatilis M) and L. neglecta. Littorina saxatilis H showed distinct seasonality in reproductive activity, unlike L. saxatilis M, and produced significantly larger eggs and embryos than the latter population. Littorina saxatilis M maintained a significantly higher weight-specific fecundity and reproductive activity throughout the year than L. saxatilis H and produced a larger number of small embryos.

The two barnacle-dwelling populations also showed distinct seasonality in reproductive activity and neither of the populations contained reproductively active females during the winter months. There was no significant difference in egg size between the two populations, but L. saxatilis B produced larger crawlaways than did L. neglecta. Even though L. saxatilis B was significantly larger in body and shell size, L. neglecta had a higher weight-specific fecundity than the former population. The possibility that the observed differences in egg and juvenile size, fecundity and seasonality between the four populations can be attributed to microscale adaptation to the local environment is discussed.

During July and August, 1907 (Voyages XCII, XOIII, XCIV, XCV, and XCVI), the s.s. Huxley worked a series of stations reaching from near Cromer to St. Abb's Head more or less parallel with the coast line, and also a series further to the north, and extending around the eastern borders of the Dogger Bank.

The Bay of Málaga is located in a high biodiversity and productivity area that harbours a wide variety of commercial species exploited by different fishing fleets. Benthic and demersal fauna from circalittoral soft bottoms have been studied using a benthic dredge (BD) (8 sampling stations) and an otter trawl (OT) (8 sampling stations on a seasonal basis). Some sediment and water column variables, as well as the trawling activity, have also been studied and used for analysing their linkage with the fauna. A total of 287 species have been found in these bottoms and fish, molluscs and crustaceans represented the most diverse and abundant faunistic groups. A new record of the decapod Hippolyte leptometrae for Spanish waters is also included in this study. Some multivariate analyses using BD samples indicated the presence of three assemblages, but these seem to represent different facies of a single benthic community due to the absence of acute sediment changes and significant differences in the fauna. OT samples only displayed differences related to seasons but not to sediment types or depth. These seasonal differences seem to be linked to biological and ecological features of both dominant and/or commercial species. Mud and organic matter contents (%OM) in sediment, as well as the temperature, were the main variables linked to the spatial distribution of the benthic community identified with BD, whereas medium and coarse sand as well as gravel contents were the main variables linked to the changes of the epibenthic and demersal assemblage resulting from OT samples. The information of this study is of importance for improving the knowledge on the biodiversity of circalittoral soft bottoms of the Mediterranean and Alboran Sea as well as for the potential creation of a Marine Fisheries Reserve in the Bay of Málaga.

Typical marine arthropods (crustaceans and halacarid mites), as well as species of recent terrestrial ancestry (insect larvae and mesostigmatid mites) coexist on mangrove pneumatophores. Both groups are affected by desiccation and are less abundant towards the tips of the pneumatophores. The degree of species associations within and between the two groups was investigated. The number of negative associations is higher for marine–marine, as compared to terrestrial–terrestrial and terrestrial–marine species pairs. When environmental stress (as represented by direct sunlight, and elevation on pneumatophores, both resulting in increased desiccation) is considered, associations tend to shift from negative to positive, and this is more obvious in terrestrial–terrestrial species pairs. These results are attributed to the longer co-evolutionary history of the marine species, resulting in a more precise partitioning of the microhabitats, while the relationships between terrestrial species are less stable, and more susceptible to environmental stress.

Several hydroid species live associated with many organisms, including bacteria. Hydroid–bacteria associations were searched for in twenty Hydrozoa species that were collected in the northern Ionian Sea and observed under blue light excitation. Of these, six showed high fluorescence on the outer perisarc, five appeared medium fluorescent, four were slightly fluorescent, and five did not show any fluorescence. Luminous bacteria were isolated and counted from the surface of the fluorescent hydroids. Their association with hydrozoan species could be explained by their feeding activity on the chitinous structures of the perisarc, as previous research on the hydroid Aglaophenia octodonta showed. Moreover, microalgae were always recovered together with luminous bacteria in the strongly, medium and slightly fluorescent hydroids. Further studies will be undertaken to characterize the luminous bacteria isolated from the surface of the examined hydrozoans as well as to better understand whether their interaction with hydroids is only related to chitin utilization or if their coexistence with microalgae in hydrozoans has an ecological meaning.