The ormer (Haliotis tuberculata L.) occurs in some abundance off the north coast of Brittany and the Channel Islands. On the French coast, exploitation of this species is not legally authorised except in the intertidal zone and the sublittoral stocks have for some years aroused the interest of local fishermen. Studies have therefore been initiated to investigate the exploitation potential of this new resource, and different aspects of the biology and ecology of the ormer have been examined so as to make use of models of population dynamics. Thus, a study of growth merits particular attention.

The current distribution and abundance of Elminius modestus (Crustacea: Cirripedia) were examined at 15 sites along the Portuguese coast in March/April 1998. Elminius modestus was found at two sites only but was absent from a site where it had previously been recorded. The site at Faro is the most southerly location on continental Europe where Elminius has yet been recorded and it is nearly 300 km south of where it was previously found.

The second maxilla is innervated typically by 35 motor neurones in Nectocarcinus antarcticus and about 39 in Cancer novaezelandiae. Muscles are multiply innervated. Within one species variations in the number of motor neurones innervating any muscle do occur but are not common.

Barnacle cypris larvae, the specialized settlement stage of the life-cycle, are classical examples of larvae showing gregarious settlement. Gregarious settlement is shown when the larva is induced to settle by established individuals of its own or of a closely related species, reflecting the ability of the larva to recognize its own type, usually by chemo-tactile detection of a particular settlement inducing factor (see Crisp (1974) for review). Sessile barnacles such as species of Balanus or Chthamalus are typically hermaphrodite and gregarious settlement is of selective advantage in promoting the possibility of cross-fertilization, in addition to allowing a settling larva to identify a habitat providing all the necessary conditions for barnacle growth and development.

This paper reports the occurrence of the fifth species of Mobula in the western Atlantic, M. thurstoni, based on specimens caught by artisanal and driftnet fisheries in coastal waters off southern Brazil.

Further measurements have been made of the penetration of daylight into the sea near Plymouth, photometers containing both vacuum and gas-filled photo-electric cells being used. The effect of obliquity of illumination on the sensitivity of these photometers was large, and has been allowed for as far as possible. The sensitivity of the vacuum cell used in the sea attained its maximum at a wave length of about that of the gas-filled cell at about 4,350. The sensitivity of both to wave lengths greater than 5,500 was small.

A comparison between the diet of the franciscana and the boto-cinza is presented through the proximate-composition and caloric value of their main prey. The fish Stellifer cf. rastrifer, Pellona harroweri, Anchoa filifera, Isopisthus parvippinnis and Trichiurus lepturus and the squids Loligo sanpaulensis and L. plei were analysed for water, protein, lipid and mineral contents and gross energy (GE). The fish are more important in the diet of the boto-cinza and squids are consumed mostly by the franciscana. Loligo sanpaulensis had the higher water content and protein was the largest fraction of the organic matter in all prey species. Squids presented greater GE values than fish. The data on prey composition and energy from this study are the first for these South American dolphins.

A new species of Cladorhizidae, from the Aleutian Islands is described and compared with all known species of Cladorhiza worldwide. Cladorhiza corona sp. nov. has a unique growth form with two planes of differently shaped appendages. Appendages are inserted directly at the stalk; a spherical or conical body at the stalk is lacking. It is the only species reported where different spicule types occur in three morphologically different areas of the sponge. The spiculation of the basal plate is characterized by the occurrence of short, thick anisoxeas and the lack of anisochelae. Anisochelae are found in the stalk and the basal appendages only. Flattened sigmancistras and (sub-)tylostyles are restricted to the crown. The arrangement of spicules is different in the basal plate, the stalk with the basal appendages, and in the distal appendages. The dimensions and combination of spicule types separate C. corona sp. nov. from all known members of the genus.

Preliminary molecular data obtained from one mitochondrial (COI) and one nuclear marker (H3) from the available species of the genus Okenia have revealed a new cryptic species of this genus. The new species (Okenia harastii sp. nov.), from New South Wales (NSW) eastern Australia, has a light brown body with scattered dark brown and white spots of different sizes, and six pairs of translucent mantle processes. Okenia harastii sp. nov. is compared with other Okenia species from NSW and with other morphologically similar species.

Chlorophyll-a (chl-a) distribution and associated physical (temperature, salinity) and chemical (dissolved oxygen) conditions off northern Chile (Humboldt Current System), during the austral summer (February–March) and autumn (May) of 1994, were studied in the region bounded by ∼18–24°S and 70–72°W (out to ∼200 km from the coast; 0–100 m depth); within this region, nutrients were measured in an area of persistent coastal upwelling (∼19–22°S, out to 80 km from the coast). Temperature and salinity distributions, as well as nutrient concentrations, indicated the occurrence of active upwelling during both cruises. Also, and together with maps of geopotential anomaly (0/200 dbar) and depth of the thermocline (15°C isotherm), their distribution suggested the presence of a mainly equatorward flow, anticyclonic eddy-like structures, and intrusions of warm (>19°C), high salinity (>35·0 psu), subtropical water towards the coast. A tongue of cooler and lower salinity water, and of lower flow fields, extended from the coast towards the offshore zone during both sampling periods, in association with higher chl-a concentrations (>1 mg m−3, >20 mg m−2 between 0 and 25 m depth) and predominance of net-phytoplankton (>20 μm). The comparison of these results with those for the winter and spring of 1993 in the same area suggest a relatively weak seasonal signal in chl-a concentration during the 1993–1994 period, with higher water column concentrations during the summer and spring periods in the selected upwelling area, though surface chl-a concentrations for the whole of the area did not vary significantly.

From May 1993 until January 1994, 788 male and 1604 female crawfish, Palinurus elephas in total, were examined from the South Wales and Cornish fisheries. Mean carapace length (CL) of Cornish crawfish was 125.6 mm for males, 132.4 mm for females and 135.0 mm for berried females, while mean CL for Welsh crawfish was 155.8 mm for males, 138.7 mm for females and 138.6 mm for berried females. The overall size distribution of male Welsh crawfish differed significantly from that observed in the Cornish population. An analysis of variance gave significant (P<0.05) differences for the factors; Site, Sex and the Sex/Site and Month/Sex interactions. Male crawfish reached greater overall size than female crawfish, but for specimens of equal CL, total lengths (TL) of females were longer than those of males. Males were heavier than females of equal CL or TL.

This study evaluated the feeding habits of the franciscana dolphin (Pontoporia blainvillei) in south-eastern Brazil. Stomach contents were collected from a total of 145 dead specimens found incidentally caught by fishing vessels or stranded between 2005 and 2015. Fish otoliths, cephalopod beaks and whole non-digested prey were used for prey species identification. A total of 9337 prey items were identified, including 26 species of teleost fishes and three species of cephalopods. The most important prey families were Sciaenidae among fish and Loliginidae among cephalopods. Franciscana dolphins tended to feed on small fish (mean = 5.25 cm) and cephalopods (mean = 8.57 cm). The index of relative importance (IRI) showed that Pellona harroweri and Doryteuthis plei were the most important prey for both males and females. The PERMANOVA test confirmed that there is no significant difference between the feeding habits of different sexes, but detected a significant difference among seasons. Overall, our results show that franciscana dolphins are predominantly ichthyophagous and non-selective in relation to the type of prey, feeding on pelagic, demersal and pelagic-demersal prey.

Specimens of European hake were collected by a traditional demersal trawl between July 2004 and June 2007 from İzmir Bay, Central Aegean Sea. A total of 2108 individuals were sampled during the study and the female: male sex ratio of the stock was 1:0.89. The length–weight relationship was W = 0.00341L3.24 (R2 = 0.994) for all individuals. A high gonadosomatic index was evident over most of the year but it was minimal from August to October. The estimated age composition was 1–5 years; the length and weight at infinity were calculated as L∞ = 54.53 cm and W∞ = 1455.77 g respectively. In addition, growth coefficient was found to be k = 0.315 y−1 and to = −0.223 y (R2 = 0.99). Total mortality ratio of the stock was calculated as Z = 1.539 y−1, while natural and fishing based mortality ratio were estimated as M = 0.579 y−1 and F = 0.959 y−1 respectively, with the exploitation ratio (E) of the stock estimated to be 0.624.

Marine worms in the genus Osedax, have specialized ‘root’ tissues used to bore into the bones of decomposing vertebrate skeletons and obtain nutrition. We investigated the borings of nine Osedax species, using micro computed tomography to quantitatively describe the morphology of the borings and provide three-dimensional reconstructions of the space occupied by Osedax root tissues inside the bone. Each Osedax species displayed a consistent boring morphology in any given bone, but these differed between bones. In bones where multiple species coexisted there was limited evidence for spatial niche partitioning by Osedax root tissues inside the bones investigated here. The new morphological data may be applied to Osedax traces in fossil bones, showing that borings can be used to indicate minimum species richness in these bones.

Lichens are a well-known symbiosis between a host mycobiont and eukaryote algal or cyanobacterial photobiont partner(s). Recent studies have indicated that terrestrial lichens can also contain other cryptic photobionts that increase the lichens’ ecological fitness in response to varying environmental conditions. Marine lichens live in distinct ecosystems compared with their terrestrial counterparts because of regular submersion in seawater and are much less studied. We performed bacteria 16S and eukaryote 18S rRNA gene metabarcoding surveys to assess total photobiont diversity within the marine lichen Lichina pygmaea (Lightf.) C. Agardh, which is widespread throughout the intertidal zone of Atlantic coastlines. We found that in addition to the established cyanobacterial photobiont Rivularia, L. pygmaea is also apparently host to a range of other marine and freshwater cyanobacteria, as well as marine eukaryote algae in the family Ulvophyceae (Chlorophyta). We propose that symbiosis with multiple freshwater and marine cyanobacteria and eukaryote photobionts may contribute to the ability of L. pygmaea to survive the harsh fluctuating environmental conditions of the intertidal zone.

Schistomysis kervillei (G. O. Sars) is a common species in Loch Ewe, Gairloch and Gruinard Bay in north-west Scotland and a rare species in the Firth of Clyde. It breeds throughout the year but most intensely in the spring and summer, to produce a spring and summer generation of young. The maximum number of young found in a marsupium was 47. The species is omnivorous. Its biology is briefly compared with that of S. spiritus (Norman) and S. ornata (G. O. Sars).

Bryde's whales are among the lesser known balaenopterids found in Brazilian waters, as well as globally. At the beginning of this project, only occasional sightings of this species were identified off the coast of São Paulo State. In this paper, we present the results of our investigations into the occurrence and behaviour of Bryde's whales along the São Paulo coast, both inside and outside the Marine State Park of Laje de Santos, as a contribution to biological and behavioural knowledge of Bryde's whales under the conservation scope. Sighting surveys were conducted from January 2003 to July 2005 in coastal and oceanic areas. During the survey, 42 sightings were made, totalling 71 individuals, between the isobaths of 20 and 3000 m. Sightings and individual rates were higher in coastal areas during the summer season. Different kinds of behaviour were observed in coastal and oceanic areas. At the 1200 m isobath, notable social interactions were observed in which four adult individuals performed breaching – the first report of this behavioural pattern for Brazil. Results suggest that Bryde's whales possibly use coastal areas for feeding and may migrate to oceanic areas for breeding, thus providing important aspects that must be considered for the proper management of Marine Protected Areas and for oceanic areas, especially considering the intensive and continuous increase of oil and gas exploitation activities in those areas. Data reported here, therefore, constitute a significant contribution in Bryde's whale research and to cetacean conservation efforts in Brazil.

The morphology and growth pattern of male and female blue mussels (Mytilus edulis) from the north Norfolk coast, UK, were studied. In allometric terms, the external shell parameters of females grew faster relative to shell length than those of males. In absolute terms, females also grew more quickly than males for all external shell parameters and for most internal body parts. At a given age, females are therefore larger than males. Females had a higher shell to tissue weight ratio and a relatively heavier foot than males. A discriminant function incorporating age, weight and shell length, width, and height correctly sexed 81% of individuals in the sample from which it was derived. Both natural and sexual selection may be involved in the evolution of sexual dimorphism in blue mussels.

The hydrodynamic properties of the shell of Chlamys opercularis have been investigated and compared with other Pectinidae. The coefficient of lift increases with increasing current speed and angle of attack. Little benefit is gained by increasing the angle of attack beyond 20 °. Allometric changes in shell shape are not sufficient to counteract the increasing weight of the animal with growth. Flow patterns over the shell indicate that a smooth and attached flow over the body of the shell becomes broken up into a turbulent, eddying wake at angles of attack beyond 20 ° and at current speeds greater than 25 cm s−1. The effect of the auricles is to enhance lift at low speeds and to help maintain stability. It is postulated that large turbulence may be further reduced if the dorsal jets act as jet flaps.

The interstitial archiannelid Trilobodrilus heideri was found to be photophobic, fairly tolerant of low salinities and responsive to water current. This latter response of orientation and progression toward a water source was gradually lost by specimens suddenly transferred to low salinities. Rhythmic gregariousness was shown to occur in this species. The relation of this rhythm to tidal factors is postulated. It is shown how the demonstrated responses may affect the position occupied by T. heideri on the shore