Munida subrugosa and M. gregaria are very abundant in the southern hemisphere, especially off New Zealand and South America. The specific identity of both species is still controversial and accurate identification is needed for conservation or ecological purposes. In this study we used univariate and multivariate methods to determine the morphological differences between both species/morphs. Analyses of covariance of ten morphological variables regressed individually on the carapace length demonstrated that the carapace (including rostrum) and eyestalks (EL) were longer, and the anterior carapace (ACW), the rostrum basis (RBW), and dactylus (DaW) and propodus (PW) of the third maxilliped were wider in M. gregaria than in M. subrugosa. In contrast, the carapace, mandible and eyestalk were wider and the rostrum was longer in M. subrugosa compared to M. gregaria. A stepwise discriminant analysis found that five body measurements namely DaW, EL, PW, RBW and ACW, were useful to discriminate between both species/morphs. The difference between the two discriminant functions provides an objective decision rule for the classification of both species/morphs. We also present the linear relationships of wet and dry masses on size, for use in biomass estimations of Munida spp. as prey.

Genetic analysis using restriction fragment length polymorphisms (RFLPs) of cytochrome b in mtDNA was made to clarify genetic variations among two Iranian Rutilus rutilus caspicus populations of commercial importance from the southern coast of the Caspian Sea. Polymorphism was detected using six restriction enzymes and a total of six composite haplotypes were identified. Four haplotypes were rare occurring only once in two regions (west and east of the southern Caspian Sea). Nucleotide and haplotype diversities were higher in the south-west region of the Caspian Sea (π=3.43%, h=23.3).The nucleotide divergence between the two populations was low (0.064%). The test for heterogeneity of composite haplotype frequencies gave no significant outcome for all samples (χ2=0.137, P≤0.05). The results indicate that significant attention should be paid to the genetic characterization of R. rutilus caspicus populations for conservation of their genetic pools and aquaculture policies at the coastlines of the Caspian Sea.

Biological observations on two deep-water shark species, Portuguese dogfish Centroscymnus coelolepis and leafscale gulper shark Centrophorus squamosus, were made for specimens caught by bottom trawl and longline between 500 and 1300 m depth off the continental slope of Galicia and Galician Bank (north-east Atlantic) in the years 1996–1998. This includes data on their bathymetric range, length distribution, size at first maturity, ovarian fecundity, uterine fecundity and the size at birth.

Using land- and vessel-based surveys, data on the relative abundance, distribution and habitat use of bottlenose dolphins (Tursiops truncatus) in Aberdeenshire waters were collected between 1999 and 2001. Bottlenose dolphins were present throughout the year, with peak abundance during the months of March to May. The occurrence of calves was seasonal, with the proportion of calves highest during the spring months. Foraging behaviour was recorded mainly in the vicinity of Aberdeen harbour. Dolphins photographed in Aberdeenshire waters were successfully matched and confirmed as Moray Firth animals. The results of the present study suggest that Moray Firth bottlenose dolphins utilize Aberdeenshire waters more frequently than previously reported. Aberdeen harbour is apparently an important feeding area, and Aberdeenshire waters are regularly used by mother–calf pairs. This has important management implications since this area of coastline does not currently form part of the designated Special Area of Conservation (SAC) for this population.

Assemblages of fish associated with exposed and sheltered sides of breakwaters and adjacent rocky reefs were sampled at coastal marinas on the north-west coast of Italy. Contrary to expectations, assemblages associated with the exposed side of artificial breakwaters did not differ from those at adjacent natural rocky reefs. Assemblages of fish associated with the sheltered side of breakwaters did, however, differ from adjacent rocky reefs and, to a lesser extent from the exposed side of the breakwaters. The internal sheltered side of marinas supported fewer species than did the external breakwaters and adjacent reefs and lacked common reef-associated species, such as Chromis chromis and Oblada melanura. In contrast, they supported greater numbers of new recruits of the sparid, Diplodus vulgaris.

Some notes on development and early life history behaviour of aquarium-reared Syngnathus acus are presented and compared with other syngnathid species, namely S. abaster. Implications in population dynamics and connectivity are discussed.

The gametogenic cycle of Scrobicularia plana was studied in Mweeloon Bay (Galway, west coast of Ireland) over the periods of February to September 1996 and January to September 1997. Quantitative (reproductive indices and oocytes size) and qualitative (gonad developmental stages) analysis identified a broad annual breeding cycle, with one protracted spawning event occurring from May until September. Early gonad development had begun by January/February. Spawning animals were first recorded at the end of May and continued to mature throughout the summer. The decrease in temperature in September coincided with the end of the spawning season and gonad regression. Although the species is predominantly dioecious, one case of hermaphrodism was recorded. A female to male sex ratio of 1.1:1 was registered. Sexual maturity occurred at a shell length greater than 20 mm; the smallest individual undergoing sexual development had a shell length of 22.4 mm. The timing of the reproductive cycle in S. plana at Mweeloon Bay is in broad agreement with previous findings on the species carried out in northern latitudes.

Gonad of the Mediterranean pectinid Flexopecten glaber was studied in order to describe the morphology and the ultrastructural characteristics of the mature spermatozoa. The spermatozoon has a 2.5 μm pyriform head and a 40–45 μm flagellum. The four mitochondria of the mid-piece are 0.6 μm in diameter. The nucleus contains dense chromatin fibres and possesses two depressions: a wide (0.19 μm) and deep (0.58 μm) sub-acrosomal one, and the other at the base of the head, less deep (0.36 μm) and less wide (0.12 μm). The objective was to situate this scallop in the phylogenetic diagrams found in the literature concerning the commercial pectinid species.

Tolerance of hypoxia in Chinese black sleeper (Bostrichthys sinensis) embryos at heartbeat stage was examined at different oxygen concentrations. Embryonic response to hypoxic conditions was expressed in terms of the intensity of variation in heartbeat rate (V). Exposure of the embryos at 25°C to 0.5, 1.0 and 1.5 mg/l dissolved oxygen (DO), caused bradycardia, which was developed within the first 10 min of hypoxia, followed by a plateau, and lasted until termination of the hypoxia. The V values were significantly affected by DO concentrations (P<0.01). Exposure of the embryos to 0.2 mg/l DO at 25°C caused a periodic heartbeat (including a period of heartbeat and a period of silence). This phenomenon was first recorded in the present study. During the period of heartbeat, the heartbeat rates were faster at first (147±5 beats per min), and then decreased gradually until the period of silence. As the exposure time increased, the duration of heartbeat was prolonged significantly from 43.4±2.4 second to 126.2±8.2 second (P<0.01), and the duration of silence was also prolonged significantly from 68.0±5.5 second to 247.9±11.5 second (P<0.01). At the beginning of exposure, the primary heartbeat rates displayed tachycardia, and their V values were significantly lower than the V values of average heartbeat rates (P<0.05). However, the V values were not significantly different between primary heartbeat rate and average heartbeat rate after 90 min exposure (P>0.05).

The evaluation of the daily ration and feeding periodicity in a Mediterranean demersal fish assemblage under natural conditions is presented. Data were obtained during four trawl surveys conducted on the shelf-edge of the central Mediterranean Sea. Recently, researchers have begun to consider this area an essential fish habitat due to its extremely high productivity and diversity. The species which typified the assemblage were the fish Macroramphosus scolopax, Lepidotrigla cavillone, Mullus barbatus, Serranus hepatus, Argentina sphyraena and Glossanodon leioglossus. Fish were collected at three hour intervals throughout four 24 h sampling periods representing annual seasons. The study was based on the analysis of catch data and stomach fullness per setting time. Results show significant variation of feeding periodicity among species within daytime. The amount of food consumed daily, calculated according to the Elliott & Persson model, is compared to the patterns reported in literature for Atlantic fish species with similar trophic habits. Higher values of daily consumption could be related to the reproductive period for most of the above mentioned species.

The diet of Sepia officinalis was studied by examining the stomach contents of 522 specimens caught off the coast of the Algarve, Portugal. A total of 49 different prey items, belonging to six taxa (Polychaeta, Cephalopoda, Teleostei, Bivalvia, Crustacea and Gastropoda) was found, indicating opportunistic feeding behaviour. The diet was examined in relation to season, sex and size. The diet of males and females were similar. For small S. officinalis, crustaceans were more important in weight, whereas for larger specimens, fish were dominant. Seasonal differences in the diet were apparent but were shown to be possibly influenced by the cuttlefish size.

An analytical method for the simultaneous determination of five booster biocides (Sea-Nine 211, Dichlofluanid, Duiron, Irgarol 1051 and Pyrithiones) and degradation product of Irgarol 1051 (M1) in sediment from Vietnam was developed by LC/MS-MS. The recovery rates and relative standard deviation of the booster biocides in the sediment were in the range of 71–108% and 1.5–12%, respectively, and the detection limits were in the range of 0.04–2 μg kg−1 dry. An analytical method for the simultaneous determination of three booster biocides (Sea-Nine 211, Duiron and Irgarol 1051) and M1 in clams was also developed by LC/MS-MS. The recovery rates and relative standard deviations of the booster biocides in the biological samples were in the range of 60–99% and 3.4–6.8%, respectively, and the detection limits were in the range of 0.24–1.1 μg kg−1.

The booster biocides in sediment from the coastal area of northern and central Vietnam were measured using this analytical method. Sea-Nine 211, Dichlofluanid, Duiron, Irgarol 1051, M1 and Pyrithiones were detected in the range of 0.09–1.3 μg kg−1 dry, <0.10–13 μg kg−1 dry, 0.11–3.0 μg kg−1 dry, 0.05–4.0 μg kg−1 dry, <0.1–0.43 μg kg−1 dry and <2–420 μg kg−1 dry, respectively. The detection frequencies of Dichlofluanid, M1 and Pyrithiones were low. The species and levels of detected booster biocides varied between sampling stations.

Irgarol 1051 and its degradation product M1 were not detected in clams.

Stomach contents and carbon (C) and nitrogen (N) stable isotope analysis were used to evaluate trophic relationships of jumbo squid, Dosidicus gigas. Buccal masses, beaks and stomach contents of large and medium maturing-sized jumbo squid and muscle from its main prey, the myctophid Benthosema panamense, were collected in the Gulf of California, Mexico during 1996, 1997 and 1999. Both the quantified C and N-isotope ratios in muscle, and stomach content analysis revealed that larger-sized maturing squid showed a higher trophic position than medium-sized individuals. However, a discrepancy between stomach contents versus stable isotope analyses was found in evaluating trophic relationships. Simple dilution models as a function of growth were used to estimate the C and N renewal dietary shift for jumbo squid. Estimates of the initial C and N pools in D. gigas with an initial age of 70 days and 210 days indicated isotopic shifts of 32% after a threefold biomass increase and 25% after a fourfold biomass increase, respectively. Additionally, beak samples of jumbo squid were evaluated as an alternative tissue to estimate squid trophic position using stable isotopes. The results showed a significant correlation between stable isotope ratios from muscle and beak samples. Muscle isotope values were higher than beak by 1% and 4% for δ13C and δ15N respectively. A test with jumbo squid beaks collected from a stomach of a stranded sperm whale confirmed the viability of this method.

Monthly sampling was conducted during one year in three zones along the estuarine gradient of Baía de Vitória, Brazil. Within each zone, unreplicated night trawls were done in deep subtidal flats located 130–210 m away and 2–3 m deeper than shallow ones. Twenty-one taxa represented 97.5% of the total mean fish abundance. The taxa Achirus lineatus (mean±SD: 2076±1269 10−4 m2), Eucinostomus spp. (694±807), Symphurus tessellatus (400±626), Sphoeroides testudineus (367±597) and Lutjanus synagris (323±445) dominated the deep assemblage (N=36) while Eucinostomus spp. (3649±4913), A. lineatus (1287±1569), S. testudineus (1208±1986), L. synagris (1101±927) and Sphoeroides greeleyi (569±1404) dominated the shallow assemblage (N=35). Taxa exclusive of one or the other depth showed extremely low abundance. The low-salinity shallow flats showed higher total abundance and taxa number than the high salinity deep locales but richness, diversity and equitability showed no significant differences among the six stations. The assemblage structure was significantly correlated to the depth structure but not to physico-chemical characteristics of the water. However, the spatial distribution of individual species varied greatly, from depth-dependent pattern to estuarine gradient-dependent pattern, with several intermediates. The community structure is singular in comparison to that of other tropical Brazilian estuaries studied to date. This is probably related to its geographical position in a transitional zone between the northern, tropical Brazilian oceanic domain and the southern, subtropical-temperate domain.

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.

A field survey to re-assess imposex and tributyltin (TBT) bioaccumulation in the gastropod Nassarius reticulatus over Galicia uncovered three populations of the invasive species Cyclope neritea, all showing some advanced imposex. One female was found to carry a mass of aborted egg capsules. The TBT pollution, now decreasing in the area, is the most likely explanation for these reproductive anomalies, and it may bear some relationship to the described population dynamics of C. neritea.

The haemogram (blood cells concentration, number and proportions of haemocyte morphotypes) of the common periwinkle, Littorina littorea, was studied in terms of its individual variations and seasonal dynamics. No granular blood cells were found. Three morphotypes of hyalinocytes were observed in the haemolymph of L. littorea and are described at both light and electron microscopy levels: juvenile round cells, intermediate cells and large mature haemocytes. The nucleoplasmic ratio, nucleus shape and location, number and size of glycogen deposits were the main characteristics used to discriminate between the haemocyte morphotypes. The enzyme cytochemistry and lectin binding studies did not identify additional haemocyte morphotypes. The experiments on BrdU incorporation showed that haemocyte population renewal occurred due to the proliferation of only one cell type, namely blast cells, which were morphologically similar to juvenile round cells. The three-month dynamics of the periwinkle haemogram and haemoblast proliferative activity are described. The blood cell concentration reached maximum values twice per summer season—in June and August, with the haemocyte proliferation activity being the highest in June. The percentage of mature haemocytes increased during the season, simultaneously intermediate cells demonstrated a decrease in number by the end of summer, with the population of juvenile cells being nearby constant. The method of haemogram analysis is positioned as a powerful technique having good potential in eco-toxicological, parasitological and immunobiological studies.

The number and distribution of ampullary pores present on the blackmouth catshark, Galeus melastomus and the velvet belly dogfish, Etmopterus spinax do not differ with the size/maturity or gender of the specimen and were found to be related to prey preference.

The diet of black anglerfish Lophius budegassa is described for the Cantabrian Sea (North Atlantic coast of Spain) from seasonal samples obtained onboard commercial vessels from January 1993 to December 1994. The stomach contents of fish caught on the continental shelf were examined, and differences in the diet in relation to age-class, season and depth were studied. The age-classes were grouped according to a cluster analysis of diet composition. As a result, three groups were obtained: the first two corresponded to juveniles between 2 and 7 years old, and the third one corresponded to adults between 8 and 15 years old. Although Micromesistius poutassou was an important prey for all ages, the youngest black anglerfish fed mainly on small benthic fish. In contrast, large prey species such as Phycis blennoides and Merluccius merluccius were eaten almost exclusively by adults. The diet composition changed during the year. The changes in the diet of black anglerfish older than 3 years were more related to seasonal differences than to between-size differences. These seasonal shifts were mainly marked by the varying importance of Trachurus trachurus and M. merluccius in their diet. Feeding intensity also showed seasonal variations, with a significant decrease in autumn. An indirect effect of depth on the feeding ecology of black anglerfish was also found, since both age and diet composition changed with depth.