The fecundity of Clyde witches was estimated from 1958 to 1962, and has been found to vary from over 49,000 eggs for a 26·8 cm fish to more than 599,000 in a 42 cm witch. Annual variations in the fecundity were found but there are not sufficient data to relate the changes to the population density as can be done with plaice. It appears that Clyde witches may grow faster, and they certainly attain a larger size than those in the Irish sea.

Density and size of Chromis fumea (Pisces: Pomacentridae) were regularly monitored during 13 months (from August 1996 to August 1997), on two artificial reefs in New Caledonia (south-west Pacific ocean): a ship-wreck (CT2) just after scuttling, and an assemblage of iron boxes (Caissons) sunk more than 50 years ago. The settlement of C. fumea was first observed 20 August 1996 and lasted 20 days. At the beginning the recruits were 1 cm size-class fish and at the end 2 cm size-class. This major settlement phase was again observed one year later (September 1997). A second minor settlement phase occurred in December 1996 on CT2. Significant immigration of adults was also observed between November 1996 (6 cm) and April 1997 (7 cm), indicating that this species is capable of medium range migration (>50 m). Population size decreased by 87·8% between the settlement of juveniles and the first immigration phase of adults. The final density of the 1996 cohort was 10·5% of the initial input of recruits on CT2 and 19·3% on Caissons. Initial density of recruits was 3·4 times higher on CT2 than on Caissons, whereas density of juveniles was similar at the end of the survey, indicating that post-settlement mortality was greater on CT2. Chromis fumea von Bertalanffy growth models were similar on CT2 and Caissons. This short-lived species is characterized by an initial rapid growth phase (K>3·36 y−1), with the fish reaching 68·5% of L∞ in three months, and a second slower growth phase (1 cm in ten months).

Hypermastus tokunagai is a eulimid gastropod infecting the sand dollar Scaphechinus mirabilis. The eulimid is easily detached from the host and thus regarded as a temporary parasite. In this study, the growth and reproductive cycle of H. tokunagai were investigated using specimens collected from S. mirabilis in the western Seto Inland Sea, Japan. Newly recruited individuals of H. tokunagai appeared in early autumn and grew rapidly, while growth was retarded from mid-autumn to winter months. A second rapid growth occurred the following summer. Based on the growth pattern, the life span of H. tokunagai was estimated to be more than 20 months. This longer life span compared to other eulimids could be due to the accessibility and population stability of its host S. mirabilis. Maturation of H. tokunagai occurred within a short period in the summer, and was synchronized with the second growth phase. Hypermastus tokunagai showed size dimorphism between sexes and an investigation on change in shell shape with growth revealed that this characteristic can be attributed to the female's acquisition of a larger shell within a short time during its maturation period.

A number of chondrichthyan fish species were caught on long-line in the Rockall Trough (north-east Atlantic) in 1997, which are first records for this area; Raja hyperborea, Raja kukujevi and Raja fullonica. The occurrence of R. hyperborea, usually found in colder boreal waters appears to be temperature related. The presence of the deep water squaliform shark Centrophorus uyato in the area was also confirmed and several species were caught at previously undocumented depths.

The Rockall Trough is an extension of the North Atlantic deep environment (Mauchline, 1990). A long-line survey was undertaken in August 1997 on the eastern and southern slopes of the Rockall Trough (Figure 1), fishing gear and procedures are described by Connolly (1997). Identifications were undertaken by means of several texts (Compagno, 1984; Whitehead, et al., 1984; Stehmann, 1997). The specimens described below were lodged in the National Museum of Ireland (NMI) and the Hamburg University Zoological Museum, Germany (ZMH). Depth ranges, positions and catalogue numbers of the specimens described are given in Table 1.

There is great difficulty in maintaining aquatic mammals in captivity, since the attempt to replicate the environment they live in poses an enormous challenge. Poor captivity facilities without environmental enrichment can lead to different consequences for animal health, including the appearance of stereotypical movements. The aim of this study was to identify these behaviours in three groups of animals, one group of manatees inhabiting a reintroduction oceanarium in Pernambuco (PE) state, and two other groups confined in corrals constructed in natural areas (estuaries), one located in Paraiba state and the other in Alagoas state, all in north-eastern Brazil. Observations were conducted using the focal animal sampling method. It was found that the animals inhabiting the reintroduction oceanarium with no environmental enrichment showed stereotypical behaviour such as ‘Back-and-forth’ movements, ‘Hitting head against the limiting structure’ and ‘Hitting the muzzle’, while animals constrained within estuaries did not. The ‘circle swimming’ behaviour was present in a higher percentage of the animals captive in the reintroduction oceanarium, although no significant difference between the sites was found. The number and frequency of occurrence of stereotypical behaviours was significantly higher in animals kept in the reintroduction oceanarium in PE than in those of other locations. Based on these results we recommend the use of appropriate environmental enrichment and the reduction of time manatees stay confined in the reintroduction oceanarium.

The urine secretion of the kidneys of Lophius piscatorius perfused with heparinized Lophius blood is very sensitive to perfusion pressure below a critical level, above which it becomes insensitive. The response of the urine flow to pressure takes the form of an exponential curve.

The blood flow through the kidneys, while rising slowly at pressures of about 20–30 mm of water, responds arithmetically to pressure above such levels.

At present it is impossible to make out whether pressure or blood flow has the greatest influence on secretion.

Water secretion in the aglomerular kidney is an active process. The oxygen consumption of the Lophius kidney is unmeasurably low, yet remains a possible factor in secretion.

This study describes the structure, growth, mortality and stock status of Litopenaeus schmitti in north-eastern Brazil. A total of 1169 specimens were captured (491 males and 678 females) from August 2011 to July 2012. Specimens were weighed and the length of carapace (CL) and total length were measured. The biometric relationships were estimated through regression analysis and growth was described through the von Bertalanffy model. Additionally, total mortality (Z), natural mortality (M), fishing mortality (F), length at first capture (Lc), maximum yield per recruit (ERMY) and longevity were determined. Females were larger (3.07 ± 0.51 cm) than males (2.68 ± 0.25 cm) and dominant in the largest CL classes. The biometric relationships for males, females and both sexes grouped showed a negative allometric growth. Females showed larger L∞ (asymptotic length) and k (coefficient of growth) (L∞ of 5.00–5.16 cm and k of 1.20–1.26 year−1) when compared with males (L∞ of 4.25–4.30 cm and k of 1.00–1.02 year−1). In general, the mortality of males (Z = 1.93–5.48 year−1; M = 1.59–1.61 year−1 F = 0.32–0.3.89 year−1) and longevity (1.11–2.16 years) were higher than those estimated for females (Z = 1.84–3.76 year−1; M = 1.70–1.77 year−1; F = 0.07–1.99 year−1; 1.07–1.78 years). Results indicated that L. schmitti stock is relatively close to the state of full exploitation. Moreover, the CL of first capture of females (2.44–2.51 cm) is below the length of first sexual maturation of the species. The lack of legislation governing shrimp fishing in the area makes this stock even more vulnerable.

The allometric growth of two groups of Nassarius vibex on beds of the bivalve Mytella charruana on the northern coast of the State of São Paulo, was evaluated between September 2006 and February 2007 in the bed on Camaroeiro Beach, and from March 2007 to June 2007 at Cidade Beach. The shells from Camaroeiro were longer and wider and had a smaller shell aperture than those from Cidade; a principal components analysis also confirmed different morphometric patterns between the areas. The allometric growth of the two groups showed great variation in the development of individuals. The increase of shell width and height in relation to shell length did not differ between the two areas. Shell aperture showed a contrasting growth pattern, with individuals from Camaroeiro having smaller apertures. The methodology based on Kullback–Leibler information theory and the multi-model inference showed, for N. vibex, that the classic linear allometric growth was not the most suitable explanation for the observed morphometric relationships. The patterns of relative growth observed in the two groups of N. vibex may be a consequence of different growth and variation rates, which modifies the development of the individuals. Other factors such as food resource availability and environmental parameters, which might also differ between the two areas, should also be considered.

The common goby Pomatoschistus microps (Krøyer), is a small and abundant brackish water fish, which becomes sexually mature after the first winter of life and usually survives for only a single breeding season (Miller, 1975). During a protracted breeding season from approximately mid-April to August or September, the goby can produce up to 9 or 10 separate batches of eggs. It is therefore considered to be an iteroparous species, but because of the short adult life-span during which spawning occurs, this species has been termed an abbreviate iteropare (Miller, 1984). The nest-building activities of the male fish, courtship behaviour and subsequent brood-care are well documented (Vestergaard, 1976).

Metacercariae of various digenean trematodes are assumed to impair the burrowing capacity of cockles Cerastoderma edule. To reveal if metacercarial infections of the gymnophallid Meiogymnophallus minutus have effects on burrowing and shell closure, a laboratory experiment using cockles with slight and extremely heavy infections was performed at water temperatures of 15, 20, and 25°C. Gaping of the cockle shell valves or other behavioural abnormalities, which have previously been ascribed to M. minutus infections, were not observed. Neither response time nor burrowing time differed significantly between slightly and heavily infected cockles at any of the temperatures tested, suggesting that the effects of the digenean trematode on its second intermediate host are not necessarily as pronounced as proposed by earlier publications, not even when additional environmental stress in the form of high water temperatures is present. Our findings question the hypothesis that M. minutus manipulates the behaviour of C. edule, in order to increase the probability of successful transmission to the avian final host.

The reproductive biology of the bathyal hermaphrodite Bathypterois mediterraneus is described based on 348 specimens caught during experimental trawl surveys carried out between 800 and 1600 m depth off the south-eastern Sardinian Sea (central-western Mediterranean). Based on macroscopic and histological gonad analysis and monthly variation of GSI, the female component of the tripodfish shows a reproductive season from March to May. The male component shows, instead, a longer spawning period probably guaranteeing continuous spermatogenesis at any time of year. The oocyte size–frequency distributions in mature component indicated that the species exhibits a synchronous-group and monocyclic ovary characterized by deposition in a single batch of eggs per year (total spawner). The species has a late size at first maturity (L50) of 119 mm standard length (SL); the smallest mature specimen was 110 mm SL.

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.

Overall incidence of metacercariae of Maritrema arenaria differed substantially at each of the three sites investigated. In each case, however, numbers were higher than those previously observed in the British Isles. Results indicate that gulls rather than waders are the more important final hosts of this parasite in the areas investigated. At one site where a more detailed survey was carried out metacercariae were more abundant on the upper half of the shore and they displayed a marked preference for barnacles on living Littorina littorea shells as compared to barnacles on rocks. Evidence would suggest that the two most likely molluscan hosts of this trematode are Littorina saxatilis and Nucella lapillus.

Blood films from a marine fish, the Cape Dory (Zeus capensis), trawled at depths between 149 and 389 m off the south and west coasts of South Africa, contained a new species of haemogregarine, Desseria zei sp. nov. The apicomplexan, found in 25/97 fish from the two regions, was generally intra-erythrocytic. Parasitaemia was usually low, but attained infection levels of 1/10 erythrocytes in one fish. The parasite stages were all gamonts and monomorphic, but likely varied in maturity; they were 3.3–4.5 μm wide by 14.7–18.3 μm long, curved with bluntly pointed ends, and existed singly within erythrocytes, or in pairs in the heavy infection. Their cytoplasm was deep blue, granular, and stained deeply at the anterior and sometimes, posterior extremities. Two or three vacuoles occurred in the cytoplasm between the anterior cap and the gamont nucleus, which was positioned in the posterior third of the parasite body. Gamonts lay close to the host cell nucleus, often curved around it. Distortion of host cells and host nucleus displacement occurred when single gamonts curved away from the host nucleus, or if they were paired. A few extracellular gamonts were observed, occasionally associated with the remnants of the erythrocyte nucleus.

Thyasira gouldi, an arctic bivalve mollusc of the family Thyasiridae, has symbiotic, probably chemoautotrophic, bacteria living in its gills. In specimens collected from Loch Etive in Scotland in 1989, after the local population had undergone an unexplained decline, the gill bacteria contained numerous virus-like particles 60 nm in diameter. The bacteria are not lysed by the virus, and the particles are not present outside the bacteria except in phagocytic vacuoles of the gill cells where the bacteria have been digested, leaving the virus particles unchanged. Similar particles have been discovered in bacterial symbionts of Thyasira flexuosa, but in much smaller numbers.

Changes in the planktonic cyanobacteria structure, composition and diversity were followed over three consecutive years (2005–2006–2007) in the Gulf of Gabes (Eastern Mediterranean Sea, Tunisia). Cyanobacteria abundances, biomasses and cell lengths were measured together with selected environmental variables (pH, salinity, temperature and nutrients). The space and time variations of the cyanobacteria in relation to the environmental factors showed a close relationship between these plankton communities and the hydrographic structure of the water column. Cyanobacteria developed over semi-mixed conditions (May–June 2006) and during the thermal stratification (July 2005). The cyanobacterial abundance and biomass was evident between 20 and 35 m in inshore stations and between 20 and 25 m in deeper stations during the semi-mixing conditions and stratification. This thermocline level coincided with the euphotic layer (21.85 ± 3.76 m) allowing access of light radiation. The cyanobacteria bloom occurred during May–June 2006 when the N/P ratio (<10) was clearly below the accepted standard molar ratio of N/P = 16/1. Commonalities among cyanobacterial genera include being highly competitive for low concentrations of inorganic P (DIP) and the ability to acquire organic P compounds. Our study showed that both diazotrophic (N2-fixing) cyanobacteria such as Anabaena sp., Chroococcus sp., Trichodesmium erythraeum, Spirulina sp. and Spirulina subsalsa and non-diazotrophic cyanobacteria such as Pseudoanabaena sp. and Microcystis display a great flexibility in the N sources which allow formation of blooms.

Two new gammaridean amphipods, Crybelocephalus birsteini sp.nov. and Halicoides discoveryi sp.nov., and a new subspecies of hyperiid amphipod, Scina wagleri atlantis subsp.nov. are described from oceanic plankton samples taken off Fuertaventura, Canary Islands.

A new hake species, Merluccius tasmanicus sp. nov., is described from New Zealand waters and another species, Merluccius australis is redescribed. Merluccius tasmanicus sp. nov. differs from all other congeneric species in the following combination of characters: upper profile of the head slowly concave; lateral line slowly concave in the caudal region; body depth 4.9–5.9 times in standard length (SL); orbital diameter 6.1–7.1 times in head length, 2.1–2.2 times in snout length and 1.6–1.9 times in interorbital width; second dorsal fin rays, 42–43; anal fin rays, 42–44; lateral line scales ∼164. Merluccius australis is redescribed to clarify the identity of this species. Merluccius australis differs from all other congeneric species in the following combination of characters: upper profile of the head straight; lateral line straight in the caudal region; body depth 6.6–7.1 times in SL; orbital diameter 4.5–5.4 times in head length, 1.2–1.7 times in snout length and 1.0–1.3 times in interorbital width; second dorsal fin rays, 40–43; anal fin rays, 40–43; lateral line scales, more than 155. Merluccius tasmanicus sp. nov. is found in New Zealand and Patagonian waters and occasionally in Japanese waters; Merluccius australis is reported in both New Zealand and Patagonian waters.

A series of experiments (1963) illustrates the stimulatory effect of 5-hydroxytryptamine on the bioluminescence of Thysanoessa raschii (M. Sars). A further series (1966) shows the effect of 5-HT and of the cinnamanilide anti-serotonin, Squibb 10,643, on the bioluminescence of Thysanoessa raschii and of small Meganyctiphanes norvegica (M. Sars), with and without stimulation by a bright light flash. The suggestion that 5-HT, or something chemically similar, may prove to be a part of the natural control system of the bioluminescence in these euphausiids is endorsed.

A review of the literature indicated a lack of quantitative data on cell division in macroscopic algae in the laboratory and particularly in situ. By means of SCUBA techniques selected red algae were collected from their in situ location on a 24 h basis through the seasons of the year. The varied oceanographic and meteoro-logical conditions on the southern tip of Vancouver Island provided shore habitats of adequate contrast. Rhodomela larix was found to be a suitable test species for quantitative work, and differentials in mitotic activity in the growing parts of this plant were explored. Using squash techniques a method of quantitative estimation of mitotic activity employing a point-counting method was developed. It was found necessary to define the limits of mitotic phases in R. larix to facilitate quantitative analysis which was carried out over 24 h periods both in July and in February. Mitotic activity in R. larix showed a well-marked periodicity, although only the July data are statistically significant. The distribution of mitotic activity throughout the day was similar both in July and in February despite the dissimilarity of photo-period, temperature and tidal factors, which suggests the presence of a circadian rhythm. This preliminary work is being continued by further in situ investigations correlated with laboratory cultures under controlled environmental conditions.