The effects of surface roughness and microsolubility on fouling levels are examined using glass and acrylic samples. It is found that both of these, often overlooked, physical characteristics have a noticeable effect on the rate of fouling. The microsolubility of acrylic results in lower fouling than found on glass despite the higher hydrophobicity of acrylic and the resultant increase in initial attraction for fouling organisms. Fouling levels were found to increase with increasing surface roughness and therefore studies on the fouling susceptibility of different materials should report the roughness values of the samples examined.

The genus Bathyporeia was established by Lindström (1855, p. 59) on specimens collected in the Baltic at Wisby and Landskrona. His description is based, apart from a reference to the epimera as small and beset with hairs, on the form of the appendages. He assigned to the genus one species, pilosa, in which the segments of the body are described as smooth, the form generally rounded, the eyes black, small and somewhat reniform, and the length under three lines. He gives a detailed description and drawing of the appendages. From the description of the antennae and of the eyes it may be assumed that the specimens were females.

1. An air turbine ultracentrifuge suitable for biological work and capable of developing a centrifugal force from 10,000 to 500,000 times gravity has been described. Advantages of the ultracentrifuge are: (1) The temperature does not vary in the centrifuge chamber over 2 or 3 degrees from that of the atmosphere; this is not sufficient to be an important factor in general biological work. (2) The cost of constructing the apparatus is very low in comparison with that of other high speed centrifuges.

2. A modification of the air turbine ultracentrifuge in which the turbine rotor drives a second rotor, in this case the centrifuge rotor which spins in a vacuum, has been described. Here the centrifuge chamber is thermally insulated which is an important item in preventing troublesome convection currents from arising in the centrifuged material where such special problems as the rate of molecular sedimentation are being observed. Forces in excess of one million times gravity can easily be obtained by such an apparatus.

The histology and histochemistry of whiting skin was studied in larval, juvenile and adult fish. The adult specimens were obtained throughout the year but there was no evidence of seasonal variation in the areas of the body sampled. The skin of the whiting is considerably more complex than that of any other teleost fish which has been described in detail. The epidermis of the mature fish comprises five layers, consisting of Malpighian cells and a variety of other structures including large cystic bullae, which ultrastructurally and histochemically are relatively amorphous but comprise a major proportion of the epidermis. A reticulum of epidermal melanocytes occurs above these structures and two types of mucous cell are described. The major histochemical feature of the epidermis was the alkaline phosphatase reaction, similar to that found in higher animals. Succinic dehydrogenase activity was found at all levels. The epithelial mucins were mainly acid mucopolysaccharide with a small sialic acid component and a greater proportion of sulphated muco-substance. The dermis was morphologically similar to that of other scaled fishes. Mast cells were particularly prominent and occasional non-pigmented ‘melanophores’ were seen.

In an earlier study of the biochemical composition of barnacle cement, Walker (1972) found that the cements of two sessile barnacles, Balanus hameri and B. crenatus contained small amounts of lipid (< 1% of total dry wt.) and carbohydrate (♎ 2% of total dry wt.) but were mainly composed of protein ( > 85 % ° of total dry wt.). Lindner & Dooley (1973) similarly found that a large proportion of B. crenatus cement was protein (80%), but Cook (1970) found only 70% protein, lipid (27.4%) being the other major constituent. There is therefore general agreement that barnacle cement is mainly a proteinaceous secretion, but controversy still exists over the amount of lipid present.

The mechanisms of accumulation of zinc and cadmium by the marine polychaetous annelid Neanthes arenaceodentata (Moore) have been studied. Animals have been exposed to EDTA chelate buffered sea water containing 65Zn and 109Cd. The calculated free ion activities of the zinc and cadmium in the sea water were 10-8.13 M and 10-7.65 M, respectively. Uptake occurs from the free ionic pool of metal and EDTA and EDTAmetal complexes are largely excluded from the animal. In unfed animals, the metals accumulate linearly with time at a rate which decreases when the temperature is reduced but increases in the presence of metabolic inhibitors. Experiments using [14C]EDTA as an extracellular marker indicate that the observed increase in accumulation caused by the inhibitors is at least partially due to media entering extracellular anatomical compartments such as the coelom and lumen of the gut which are normally isolated from the seawater by cilia or sphincters.

Surface longline targeting mainly swordfish is considered a major threat for loggerhead turtle populations in the western Mediterranean Sea. For this reason, it is necessary to analyse the relationship between the characteristics of longline sets and loggerhead turtle by-catch. The objective of this study is to look for differential spatial distribution of loggerhead turtle and swordfish captures along the longline to gain insights that might be useful to diminish unintended, incidental catch of turtles without affecting the captures of the target species.

Longlines are divided into transects separated by two consecutives buoys. During the 1999 fishing period of the traditional (without roller) Spanish surface drifting longline fleet (August to November), 59 technically homogeneous fishing operations, composed of 23 sections each, were observed. Chi-square test was used to compare loggerhead turtle and swordfish distributions among transects with those expected at random. Significant differences were obtained only for loggerhead turtles, with 93% of the specimens caught in the second half of the longline transects, which were retrieved from the sea during daytime. Significant differences were not found for the swordfish along the whole longline or for loggerhead turtle captures retrieved during daytime. We conclude that swordfish captures are independent of retrieval time whereas the incidental catch of loggerhead turtles occurs mainly during daytime, probably because loggerhead turtles use vision to locate baits.

Lipids of sulphur-oxidizing bacteria isolated from Thyasim flexuosa had large amounts of 18:l(n-7) together with lesser amounts of both 16:l(n-7) and 16:0 as their major fatty acids. Smaller amounts of the cyclopropyl fatty acids, cyclic δ9,10 C16 and especially cyclic δll,12 C18 were also present. A similar pattern was found for methylotrophic bacteria isolated from Thyasira, Myrtea and Lucinoma, except that 16:l(n-7) and 16:0 were both present in larger amounts than 18:l(n-7) and small amounts of cyclic δ9,10 C16 and lesser amounts of cyclic All,12 C18 were present in all cases. The fatty acids 18:l(n-7), 16:l(n-7), 16:0, cyclic δ9,10 C16, and cyclic δll,12 C18 were all present in varying amounts in several free-living, non-marine, sulphur-oxidizing bacteria analysed, and in one bacterium both cyclic δ9,10 C18 and cyclic δll,12 C20 were abundant. Branched-chain fatty acids and polyunsaturated fatty acids were not detected in any of the sulphur-oxidizing or methylotrophic bacteria analysed. The lipids of the sulphur-oxidizing and methylotrophic bacteria consisted largely of phosphatidylethanolamine, phosphatidylglycerol and cardiolipin. The results are discussed in terms of fatty acids as indicators of nutritional relationships in bacterial-invertebrate symbioses.

The behaviour of Cerithidea decollata, a common western Indian Ocean mangrove tree climbing gastropod, was studied in Mida Creek, Kenya. At the study site, this snail mainly lived in Avicennia marina dominated areas, i.e. in the mangrove belt between high water spring tide and high water neap tide levels. Not a single individual was found on the less common mangrove tree Lumnitzera racemosa, living just above the A. marina level (together with terrestrial grass), and was very rarely recorded on the common Rhizophora mucronata, bordering the seaward side of the A. marina belt. No significant gradient of C. decollata density was found within the whole 150–200 m wide belt. The majority of C. decollata rested on tree trunks during high tide, creeping on the mud flat below the tree for part of low tide, and returning on the trunks well before being reached by the water. This migratory pattern was more evident at spring than at neap tide, at day than at night time and it was strongly influenced by the shore level of the mangrove zone in which animals resided. While C. decollata from lower shore levels neatly massively migrated twice a day, individuals from upper levels showed a more continuous and irregular activity, sometimes crawling on the mud even at high water of spring tide, when they experience just a few centimetres of water for no more than one to two hours.

The common dog-whelk, Nucella (= Thais, = Purpura) lapillus (L.), is often selected for ecological, physiological and genetical study. In recent years most workers have based their investigations on the work of Moore (1936; 1938a, b) and most have used his observation that ‘at the onset of maturity, growth of the (shell) lip ceases and instead the region near the lip thickens, while the lip itself becomes rounded and a series of rounded “teeth” develop on its inner side which still further occlude the opening’. It has been assumed that all animals showing these features are adult, and have ceased growing, for Moore goes on to say ‘occasional specimens are taken in which the presence of a second set of teeth within the marginal ones indicates that the original stoppage of growth was followed by a second slight growing period, this in turn being replaced by a second period of thickening and growth stoppage, but such specimens are too rare to be a serious source of error.’ This assumption has been incorporated into most subsequent reviews of shore ecology.

Understanding the spatial distribution of fish species and fish trophic guilds in reef environments may help improve our knowledge about ecological relationships and therefore favour sound strategies for sampling, coastal management and conservation policy. To verify if small-scale changes are important in forming the fish community structure at a tropical rocky coastal island, we assessed the depth, structural complexity and wave exposure gradients. The community structure changed along all gradients analysed. The trophic guilds found on the sheltered, low and intermediate exposure zones, in the deepest areas and in areas of highest structural complexity showed significant differences when compared with the general assemblage. Rocky reefs, even of narrow (transversal) extension, can show great changes in fish community structure at so small a scale that these changes are generally overlooked. The relationships evidenced between community and environment provide strong support for the importance of considering a wide array of such distinct environmental conditions when determining the structure patterns of the community.

Boring sponge diversity in the area of the Conero Promontory, the most important rocky emergence on the west coast of the Adriatic Sea (Italy), was assessed. Four species were recorded; one of them, Cliona adriatica, is new and is described here. The new species differs from all the other excavating sponge species, characterized by yellow papillae and lacking or scarcity of microscleres, in the large size of the boring chambers and the presence of numerous styles. Cliona adriatica is present on about 12% of the surface of rocky bottoms in the Conero Promontory area. The impact of this highly destructive species on the carbonatic micritic rock of the promontory was evaluated calculating a relationship between the volume of the boring chambers and the surface of the epilithic portions. Consequently, it was estimated that 1 cm2 of epilithic tissue corresponds to 8.5 g of excavated rock. The recorded correlation between the excavated volume and the area of the papillar zone (roughly the area of the substratum affected by the erosion) allows an estimation of the substratum removed by a boring sponge, using only visually oriented, non-destructive, sampling methods.

The impact of date-mussel fishery on substratum rugosity was evaluated at Capo Noli and Isola di Bergeggi (Savona, north-western Italian coast) in the summer of 2004. A new measure of substratum rugosity was used as a surface-dependent index of complexity. The results were compared between impact and control sites using two-way analysis of variance and suggested that the mussel fishery reduces substratum complexity.

Basking sharks Cetorhinus maximus tend to aggregate in summer at favoured locations along Britain and Ireland's west coast. Sharks have been described approaching and close-following one another, often to one side. This has been interpreted as putative pre-mating behaviour. At aggregation sites around the Inner Hebrides we used boat-based observation and in-water and overhead drone video-photography to document behaviour and to determine the sex of individuals. It was confirmed that a shark will frequently move purposely towards another from a distance and swim to maintain a position either directly behind or closely to one side of a conspecific for short periods. Contrary to expectation, we found no relationship between the sex of a shark or its size and close-following. This suggests that following behaviours are not mainly related to courtship. Further, abrasions on the nose suspected to be related to male behaviour were found to occur on both sexes, although abrasions on pectoral fins, similarly suggestive of mating-related behaviour, were predominantly on females. Breaching by basking sharks has also been proposed as a means of attracting the opposite sex. We observed breaching by solitary sharks but commonly by sharks within aggregations, and at other times by more than one shark on the same day at the same time; but there was not any clear evidence to indicate that breaching is primarily related to mating. More likely individuals show close following chiefly for feeding-related hydrodynamic advantage. It remains plausible however that mature sharks make use of feeding aggregations to initiate pre-courtship behaviour.

1. Regeneration from different levels in the polychæt worm Chætopterus variopedatus has been studied.

2. Regeneration can occur posteriorly from any segment, but anteriorly only from segment XIV forwards.

3. Where regeneration occurs at all, given sufficient time, it will be complete, i.e. the original segments occupy in the new worm the relative position they originally occupied in the old worm.

The spectral composition of the light of Chaetopterus variopedatus has been measured by means of spectral niters and multiplier phototube. Spectral emission extends from about 405 to 605 mμ, with a maximum at about 465 mμ. The spectral curve of Chaetopterus light is compared with a human visibility curve (scotopic vision), a visibility curve for Limulus, and an absorption curve for fish visual purple. Luminous efficiencies, based on these curves, are calculated.

Reproduction of newly established populations of the warm-water Atlantic Mediterranean wrasse Thalassoma pavo is here reported for the first time in the Ligurian Sea, and mating behaviour is described in detail. The reproductive season (May to October) may be divided in three stages: (1) pre-mating (mid-May to the end of June), during which terminal-phase (TP) males establish territories and start courting females; (2) mating (end of June to the end of August), with a mean frequency of up to one spawning event ind−1 h−1; and (3) post-mating (September to mid-October), when TP males remained inside territories but no spawning events were recorded. Mating followed two distinct modalities: pair spawning and group spawning, the latter replacing the former when population density exceeded 10 ind 100 m−2. Four phases have been distinguished in both modalities: (1) approach (pair) or gathering (group), to establish the contact between potential partners; (2) acceptance (pair) or priming (group), in which partners establish a common behavioural pattern; (3) ascent to near the sea surface; and (4) spawning. The saddled sea-bream Oblada melanura has been seen to predate intensively on the large cloud of sexual products released by groups.

Describing species has been a formal, intellectually rich and influential applied and basic area of study for many of the past 260 years. While formally described eukaryotic diversity still falls short of estimated eukaryotic species diversity by many hundreds of thousands of species, some recent accounts have suggested a growing number of taxonomists are within reach of describing all extant species. We present a case study that illustrates, to the contrary, a recent ‘taxonomic impediment’ in part attributable to derogation of taxonomy as a scientific discipline: contemporary practice has re-interpreted taxonomy largely as an endeavour in enumerating species. We argue that challenges lie in (1) a poor understanding of taxonomy's epistemology; (2) excessive displacement of interest toward ecological or molecular studies; (3) over-interpretation of the contributions of multiple authors describing a species; and (4) perspectives that are strongly influenced by well-known taxa. The historical and recent literature on scyphozoans reveal ghosts of taxonomy's past that persist in the present, but suggest also that a renaissance enabled by integrative taxonomy is possible in the (near) future.

From 1989–1992, at quarterly intervals, the National Rivers Authority (NRA) (Thames Region) Thames Estuary Benthic Programme sampled 28 sites within the estuary for benthic macroinvertebrates; meiofauna samples were also taken for the first year. At one subtidal site, situated off Canvey Island, over 200 invertebrate species over the survey period from a sample area of 4·4 m2 were recorded. This species richness was far higher than surrounding sites, including those further out into the North Sea. The most important groups at this site were Nematoda (77 spp.), Crustacea (46 spp.) and Polychaeta (40 spp.) and a species capture curve for macroinvertebrates continued to rise after 44 day grabs. The mean biomass of the site (248 g wet weight /m2) was 20 times that of any other site in the outer estuary. The substratum at the site was highly heterogeneous, yet comparatively stable due to its situation at the base (>20 m depth) of a man-made shipping channel, the provision of a large number of niches perhaps explaining the high biodiversity. The anthropogenic influence on a naturally low biodiversity area emphasises the importance of these ecosystems when considering the conservation of global biodiversity. Methods to determine the relative importance of ecosystems are discussed.

Enzyme and colour phenotypes were determined within a single mid-shore aggregation (n = 106) of the anemone, Actinia equina L. on the east coast of Britain. On the basis of allelic variation at four enzyme loci, a large number (n ≃ 30) of genotypes were distinguished of which only three consisted often or more anemones. Little evidence was found of obvious genotypic clustering, a result which was unexpected since this species broods young which are genetically identical with their parents, and which are potentially available for local (within site) colonization. We propose that the unexpectedly high level of genetic variability encountered at this site, can be explained by the following factors: (1) site and anemone longevities are probably measurable in tens of years, (2) distances travelled by anemones during their lifetime may be considerable, thus resulting in extensive inter-digitation of clones over time, and (3) the reproductive strategy of A. equina incorporates sexual reproduction with a planktonic dispersal phase.

Nearest-neighbour analyses applied to the distribution of phenotypes within this aggregation revealed several examples of auto-phenotypic under-dispersion. These results, together with (1) departure from Hardy–Weinberg equilibrium at a hexokinase locus, (2) evidence of linkage disequilibrium between hexokinase and malate dehydrogenase alleles, and (3) linkage between alleles at both these loci with a colour phenotype (grey pedal disc), all indicate that the genetic composition of this group of anemones had been strongly influenced by founder effects followed by clonal reproduction.

A comparative analysis of the size distributions of the various phenotypes and genotypes yielded few conclusions relating either to colonization history or to differential selection; reasons are given to account for this failure.