Seasonal changes in altimeter data are derived for the North Atlantic Ocean. Altimeter data are then used to examine annually propagating structure along 26°N. By averaging the altimeter data into monthly values or by Fourier analysis, a positive anomaly can be followed from 17°W to ∼50°W along ∼26°N. The methods give a westward travel speed of 1° of longitude a month and a half-life of one year for the average decaying structure. At ∼50°W 26°N, the average structure is about 2·8 years old with an elevation signal of ∼1 cm, having travelled ∼3300 km westward. The mean positive anomaly results from the formation of anticyclonic eddies which are generally formed annually south of the Canary Islands by late summer and which then travel westward near 26°N. Individual eddy structure along 26°N is examined and related to in situ measurements and anomalies in the annual seasonal concentration cycle of SeaWiFS chlorophyll-a.

Subtidal assemblages of epibiota on vertical and on horizontal surfaces of two natural reefs and two concrete breakwalls were sampled photographically during autumn and winter of 1998. Differences in the assemblages on the two types of substrata (natural reefs and concrete breakwalls) were detected between assemblages on horizontal surfaces, but not on vertical surfaces. The covers of several individual taxa (e.g. Herdmania momus, serpulid polychaetes, coralline encrusting algae) and number of sponge taxa showed clear differences between the two types of substrata. There were great differences between the assemblages on vertical and horizontal surfaces on each natural reef and artificial structure. Invertebrates consistently covered a larger area on vertical than on horizontal surfaces with sponges (as a group) and the ascidian Herdmania momus, the dominant invertebrates on these reefs, clearly showing this pattern. Nevertheless, this pattern was complex for sponges because several species covered a larger area on horizontal than on vertical surfaces and there was no difference in the number of taxa of sponges between the two orientations on natural reefs. Algae, contrary to the results of previous studies, did not show any consistent differences in their covers on vertical or on horizontal surfaces. The results of this study indicated that orientation may be of greater influence on the biological diversity of epibiota on subtidal reefs than whether reefs are natural or artificial.

The living morphology and infraciliature of a marine ciliate, Certesia quadrinucleata, isolated from an abalone-farming pond near Qingdao, China, have been re-investigated, and some new information about this ‘well-known’ species documented: a caudally located contractile vacuole and the highly stable ciliary pattern on dorsal side. Based on previous and present studies, an improved diagnosis is supplied: size 50–90×35–70 μm in vivo; ovoid body shape with a sharp-angled projection on the right anterior edge; adoral zone with 22–27 membranelles and a prominent paroral membrane; 11–12 frontoventral and 4–5 transverse cirri; left marginal row with 5–7 cirri; five dorsal kineties; generally four macronuclear nodules; contractile vacuole positioned at posterior end; marine.

The morphology and infraciliature of a population of Pseudokeronopsis flava, a yellow-coloured ciliate collected from the coastal water near Zhanjiang, South China are investigated and described. Based on previous and present studies, an improved diagnosis is supplied: yellow to yellow-brown coloured marine Pseudokeronopsis, in vivo 140–350×30–50 μm with flexible and slender body; bicorona comprising about five pairs of frontal cirri; one buccal, 2–3 frontoterminal and 2–4 transverse cirri; midventral rows consisting of ≈30 pairs of cirri, which terminate subcaudally above the inconspicuous transverse cirri; about 50 adoral membranelles; left and right marginal rows separated at posterior end; 3–4 dorsal kineties; colourless, blood-cell-shaped cortical granules ellipsoid in shape, distributed over whole cell while yellow to yellow-brownish pigments positioned in a P. rubra-pattern; contractile vacuole positioned in posterior 1/4–1/5 of body; numerous macronuclear segments.

A new genus of marine, interstitial schizorhynch (Platyhelminthes: Kalyptorhynchia) is described from sediment collected in Mosquito Lagoon and Indian River Lagoon, Florida, USA. Smithsoniarhynches is characterized by the presence of proboscis hooks constructed of ten individual spine-like teeth that emerge separately from a basal plate. Histology and confocal laser scanning microscopy are used to reveal additional details of the proboscis musculature and reproductive anatomy. The type species, Smithsoniarhynches sherryreedae sp. nov., is characterized by well-developed proboscis pads, four pairs of proboscis retractor muscles, and a pharynx in the midbody region. The male reproductive system consists of an anterior testis, muscular seminal vesicle, copulatory bulb lined with spiral and circular muscles, and a sclerotic stylet. The female system consists of an unpaired vitellarium, ovary, uterus and bursa. The bursa tissue surrounds a muscular bursa seminalis with distinct sphincter muscles. The new genus is compared with the known 11 genera within the Gnathorhynchidae to establish a tentative hypothesis of relationships.

A study was initiated to identify trematode patterns in Cyathura from two key sites in the Mondego Estuary: a Zostera-bed and a sand flat. The two subpopulations of Cyathura differ, as the annual recruitment success is much higher and more regular on the sandflat than on the Zostera-bed.

Counting and sizing of trematode cysts inside the body of preserved Cyathura specimens enabled a description of trematode patterns in space and time. Further identification of trematodes was based on DNA studies of unpreserved cysts as well as on identification of parasites in co-occurring mud snails. Two trematode species dominated in Cyathura: Maritrema subdolum (cysts around 190 μm) and a hitherto unknown Levinseniella species (cysts around 340 μm), the latter being the most frequent one. Generally, the prevalence of both species peaked during winter months, when migratory water birds occur in the estuary. Cyathura from the Zostera bed harboured more infections per specimen than those from the sand flat. A much higher density of mud snails ≥52 mm (which can be host to microphallids) and a low abundance of Cyathura are thought to be the main reasons for this pattern. Field data did indicate a host size-dependent maximum number of cysts in Cyathura that could be a result of enhanced mortality at high cyst intensities. Furthermore, parasites were underrepresented among ovigerous Cyathura specimens, suggesting a negative impact on gametogenesis. As a consequence, microphallid trematodes may be a critical factor controlling recruitment strength in Cyathura, especially at the Zostera-site.

Nematode assemblages were studied from four sublittoral sites at 50–56 m depth in the Gulf of Maine, north-eastern coast of the USA, within the context of an open ocean aquaculture experimental site. All four sites, two potential impact and two control sites, had a similar muddy–sand bottom and low organic content. Seventy genera in 27 families were recorded from a total of 1072 individuals. All but one taxa could be related to known genera. Family Comesomatidae was the most dominant with close to a third (27·6%) of the total individuals. At the genus level Sabatieria and Setosabatieria were most dominant with a quarter of the total number of individuals. Composition of dominant families from the Gulf of Maine differed from all hitherto reported sublittoral or deep-sea communities from both sides of the Atlantic, and most similar with European estuaries.

Nematode diversity at the genus-level was reasonably high and was comparable with Mediterranean samples. Most diversity indices ordered the four sites similarly with Site 2 as the most diverse followed by Site 5 and then Site 6. By contrast the relative diversity of Site 4 depended on the index employed and its k-dominance curve crossed that of the others. Furthermore based on clustering the community at Site 4 was least similar to the others. Although these observations could be related to the fact that Site 4 is within the expected impact zone of the fish cage, the low number of fish introduced by the time of sampling and the lack of any difference in the maturity index among all the sites argue that these results can be considered before-impact data for further monitoring of the open ocean aquaculture experiment.

A new paradigm where morphological information is documented and communicated using digital multifocal images is introduced. Each video image is comparable with visualization of a specimen under a microscope where the movie can be played back and forth to mimic focusing through a specimen. Web-based and openly accessible digital multifocal images were used to document and effectively communicate the morphology of all the identified genera in this study. This approach for documenting and communicating survey results is proposed as a benchmark for future similar studies that would enhance standardization and quality control of meiofaunal taxonomy, ecology and biodiversity studies.

New records are given of the occurrence of the warm-water barnacle Solidobalanus fallax in Britain and Europe. This barnacle is not found on rocks or stones, but settles on biological substrata, including algae, cnidarians, bivalves, gastropods and crustaceans. It also settles on plastic bags and nets, plastic-coated objects such as crab and lobster pots and octopus pots made of ceramic or plastic. With one exception the species was unrecorded in Europe before 1980; it may have increased in abundance during recent years as a result of rising temperatures. The cyprid larvae, which can metamorphose on plastic Petri dishes, appear to be adapted to seek out ‘low energy’ surfaces. One of the habitats colonized by S. fallax is the sea-fan Eunicella verrucosa, where it seems to have increased in recent years, possibly to the detriment of the cnidarian host. Solidobalanus fallax has the potential to be a serious pest of fish-farming structures to the south of Britain.

Nautilocaris saintlaurentae gen. nov., sp. nov., is described and illustrated from hydrothermal vents in the North Fiji Basin and Lau Basin in the south-western Pacific. This new taxon is assigned to the Alvinocarididae. It has a well-developed, dorsally dentate rostrum, carapace with pterygostomian spine present, eye broadly fused mesially, epipod–setobranch complex present above pereopods, and appendix internae on second to fourth pleopods greatly reduced. This combination of characters places it in an intermediate position between a group of species in the genus Alvinocaris with well developed, dorsally dentate rostrum, carapace with pterygostomian spine present, eyes narrowly fused mesially, epipod–setobranch complex absent and well-developed appendices internae on second to fourth pleopods, and Mirocaris fortunata with rostrum unarmed, carapace with rounded pterygostomian angle, eye broadly fused mesially, epipod–setobranch complex present above pereopods and appendices internae on second to fourth pleopods greatly reduced. The habitat of the new species is briefly described.

Total lipid (TL) and lipid-class composition in Acanthostepheia malmgreni (Crustacea: Amphipoda) from 240 m depth in Conception Bay were determined from samples collected monthly throughout 1999 and 2000. Variation in lipids among life history stages was studied in relation to the reproductive cycle of A. malmgreni and the timing of the major annual sinking event following the spring phytoplankton bloom in April. Total lipid remained relatively constant in first year juveniles [mean 4·4% dry mass (DM)], after which it gradually increased with the first signs of development of sexual characteristics and the sedimentation of spring bloom material in May. Triacylglycerol (TAG) was the dominant neutral lipid in all stages, with phospholipid (PL) the dominant polar lipid. Highest net accumulation of TL and TAG occurred in a group of large age 2+ individuals from October 1998 to May 1999, and in age 1+ immature males and immature females from July to November 2000 (1·4 mg TL month−1; 0·8 mg TAG month−1). Phospholipid quantities within the population were relatively constant at ≈2% DM. Maximum TL in the population (13% DM) was observed in large adults and some large immature individuals, and significant decreases in both TL and PL were recorded in mature females during the brooding period. This study reveals a dependence of A. malmgreni on seasonal lipid accumulation for reproduction, and a clear trophic link between the amphipod population and the pelagic production cycle.

The diet and feeding behaviour of the burrowing shrimp Alpheusmacellarius (Decapoda: Alpheidae) in sea grass beds in the Philippines were evaluated in the present study through field and laboratory activities. Sediment organic matter and sea grass appear to be important food sources for the shrimp based on the combined results of field surveys, gut content, stable isotope (δ13C) and sediment C content analyses. There was a significant positive correlation between organic matter content in the sediment and shrimp densities. In terms of behaviour, observations under controlled set-ups detected marked trends in duration and frequency of feeding. Feeding bouts became longer and more recurrent as the days progressed. Periodicity was exhibited with burrowing generally performed in the morning and feeding in the afternoon. A deposit-feeding mode was predominant in tank conditions as demonstrated by the shrimp's behaviour and burrow features.

Males of the hermit crab Pagurus filholi show pre-copulatory mate guarding behaviour to keep a receptive female from other rival males during the breeding season. Guarding males are often replaced by other males via contest competition. Shell size fit and shell species of males effects were investigated to see if their ability to defend females against rivals depends on their shell. Shell size fit and shell species of guarding males were experimentally manipulated and then, the males were allowed to guard a female and interact with rival males of various sizes. Contest outcomes depended on neither the shell size fit nor shell species of the guarding males, and depended on body size ratio between guarding and rival males. When the body size of guarding and rival males was similar, however, guarding males in large fitting shells defended their female mate significantly more often than those in small fitting shells. For Chlorostoma lischkei shells, small males preferred larger shells during the breeding season than after the breeding season. The plasticity in the shell size preference of small males suggests that they compensate for body size disadvantage in mating versus larger rivals and for higher defence ability of female mates versus similar sized rivals.

In a field experiment, the accumulation of trematode (Echinostomatidae) metacercariae by the New Zealand cockle Austrovenus stutchburyi was compared among treatments with different seabed hydrodynamics and sedimentation rates. There was no significant difference among the treatments in the rate at which cockles accumulated metacercariae, suggesting that infection rates are not influenced by water flow conditions within the normal range experienced in natural habitats. There was, however, substantial spatial variation in infection rates among the experimental plots. This result indicates that metacercarial accumulation varies horizontally as well as vertically within the intertidal zone.

The epibiotic iron-encrusted biofilms occurring on the shell of the bivalve Montacuta ferruginosa were examined over an annual cycle in order to determine possible variation of the iron-encrustation. Among the 379 examined specimens, well-coated bivalves always predominate. However, it was found that about 50% of the small-sized bivalves were uncoated or weakly coated during the summer months. This result can be explained by the life history of the bivalve and by the physico-chemical conditions in the sediments.

The effect of light intensity on the course of embryonic development of squid (Heterololigo bleekeri) was examined. Heterololigo bleekeri embryos at an early stage were incubated in the egg cases under six to seven gradients of light intensities which varied from constant darkness to intensive light >1000 lx (12L:12D for all experimental groups except for the constant darkness group). Duration of hatching in every experimental group ranged from seven to 15 days with a peak for ≈30–50% of total number of hatchlings. However, there were no particular relationships between light intensities and duration of embryonic development, duration of hatching, number of hatchlings at hatching peak, and body size of hatchlings. In all groups, body size of hatchlings increased up to seven days post-hatching and thereafter did not change remarkably. Just after hatching, strongly positive photo taxis was observed for H. bleekeri

Reproductive aspects of Eledone moschata from the Spanish waters of the Gulf of Cádiz are reported for the first time. The species is relatively abundant over the continental shelf and it is caught as by-catch by the bottom-trawl fleet. Monthly samplings throughout one annual life-cycle showed a sex ratio with a female dominance (0·45:1). A four stage maturity scale was used for both sexes. The reproductive period was determined from monthly evolution of these stages as well as that of several maturity and condition indices. The breeding season extended from October to June, with spawning peaks in October and March–May, the second one being more important. Length and weight at maturity (mantle length50, body weight50) were estimated at 7·8 cm and 97 g in males, and at 12·2 cm and 274 g in females, respectively. Total fecundity, estimated from 52 mature females, was 443·5±154·4 oocytes on average. The mean size of mature oocytes and the mean length of mature spermatophore in mature females and males was 10·24 mm (±1·07) and 13·88 mm (±1·60), respectively.

A new species of Didemnum was discovered during a recent biodiversity survey of Praia da Baleia, São Sebastião, São Paulo State, Brazil. This species has a unique and peculiar type of spicule composed by four calcareous spheroids grouped together to form a tetrahedral structure. In other aspects, the new species is similar to certain other whitish tropical Atlantic American didemnids formerly assigned to Didemnum candidum.

The role of sandy beaches as nursery areas for 0-group anchovies (Teleostei: Engraulidae) was investigated in a tropical bay, south-eastern Brazil. Spatial and temporal (diel and seasonal) changes in fish abundance and environmental influences at two beaches were assessed, one located in the outer zone, and the other in the inner zone of Sepetiba Bay. The two sites were sampled quarterly at the same time (0800, 1100, 1400, 1700, 2000, 2300, 0200 and 0500 hours) over a 24 h cycle by beach seine with three replicates, between winter 1998 and autumn 1999. Environmental variables of water temperature, salinity, and transparency (as % depth) were taken at each fish-sampling occasion. Five species in three genera (Anchoa tricolor, A. januaria, A. lyolepis, Cetengraulis edentulus, and Lycengraulis grossidens) were identified. Anchoa tricolor and A. januaria were the most abundant species and indications of spatial separation were detected, with A. tricolor being more abundant in the outer bay (higher salinity and lower temperature), while A. januaria, in the inner bay (lower salinity and higher temperature). Overall, young-of-the-year Engraulidae peaked during the day, perhaps an adaptation to avoid competition with other abundant species which peak at night. Maximum densities of anchovies due to 0-group influxes were found in spring and paucity in summer. Spatial segregation to optimize resource uses and daily habits adapted to take advantage of the rich planktonic bay waters seems to be the strategy developed by these closely related species to use the area during early life cycle. Their high abundances suggest the suitability of the sandy beaches as nursery areas.

Data from several sources and original data are presented regarding sightings, strandings and incidental captures of leatherback sea turtles (Dermochelys coriacea) on the Brazilian coast in a 33 year period, from 1969 to 2001. Two of the turtles were small juveniles (curved carapace length=40 cm and approximately 85 cm) and the remaining animals with known carapace size were large juveniles or adults. The origin of leatherbacks observed in Brazil is unknown. Several colonies in South America, including a Brazilian one, in the Caribbean, in western Africa and even in eastern South Africa could be the source of these turtles. The data presented here suggest that more effort should be directed to the assessment of the impact of fishing gear and marine pollution on leatherbacks and that systematic surveys on beaches should be maintained in order to monitor long term fluctuations in stranding levels and spatial stranding patterns. Genetic studies and satellite telemetry would be helpful in clarifying the origin of leatherbacks stranded or incidentally captured on the Brazilian coast.

During 1992–2002 approximately 110 strandings of minke whales Balaenoptera acutorostrata were recorded in Scotland (UK). Most strandings were recorded between April and November, with a peak of strandings of males in July and August. There were two length modes at 4–6 m and 7–10 m. Stomach contents samples were obtained from ten animals. The diet comprised mainly sandeels (Ammodytidae, around two-thirds of the diet by number or weight) and clupeids (herring Clupea harengus and sprat Sprattus sprattus). Results on diet are consistent with results from whaling catches in the North Sea. The possibility that minke whales compete with fisheries is discussed.