Seagrass beds are common features of coastal ecosystems worldwide, and their associated infauna are often more productive and diverse than in unvegetated habitats. Little is known, however, about the ecology of meiofaunal communities living in seagrass sediments. We compared the abundance and biomass of sediment meiofauna inside and outside an intertidal Zostera muelleri bed in southern New Zealand to assess the impact of seagrass cover on meiofaunal distribution. Nematode community structure, diversity, and feeding groups were also compared between habitats and sediment depths (0–2, 2–5 and 5–10 cm) to evaluate the effect of seagrass on nematode communities. Meiofaunal biomass was significantly higher inside than outside the Z. muelleri bed, but secondary productivity inside the bed is likely to have been limited by the availability of labile organic matter. There were significant differences in nematode community structure between unvegetated, sparsely vegetated, and densely vegetated sites (102 m scale), as well as between sediment depths (cm scale). No significant differences were found in depth-integrated (0–10 cm) nematode diversity between sites, but vertical gradients in diversity differed between vegetated and unvegetated sites. Epistrate feeders were the most common feeding group in unvegetated sediments whereas most feeding groups were common inside the seagrass bed. Findings from this study indicate that seagrass beds can have a marked impact on infaunal structure and function over small spatial scales through their effect on sediment characteristics and organic matter input. Some unexpected trends observed in the present study, i.e. low meiofaunal biomass at the vegetated sites, and lower abundance of copepods inside than outside the seagrass bed, suggest that the nature of seagrass–invertebrate interactions may depend on habitat characteristics and the identity and ecology of species considered.

The jumbo squid Dosidicus gigas is the only ommastrephid commercially caught in Mexico. Despite the economic and ecological importance of this species, little is known about its early life stages. The relationship between the presence of paralarvae and mesoscale oceanic features was investigated for the first time in the central Gulf of California, Mexico in February, April, June and September of 2008. A total of 86 paralarvae were found only in June and September (summer season), in the well-stratified column water where the thermocline was evident and warm sea surface waters (27.7° to 29.4°C) dominated. The greatest abundance of D. gigas paralarvae was observed within 2.23 to 3.48 km of the main front. The mantle length of the smallest paralarvae corresponded with the mantle length at hatching. The San Pedro Mártir Island–Santa Rosalia transect and Santa Rosalia–Guaymas transect were determined as the main hatching localities in June and September respectively. The number of paralarvae found in this study contrast with the potential fecundity of mature females which are found throughout the year.

Ultrasonic treatment, a relatively less explored technology in water disinfection, was used to quantify the energy required for the destruction of larvae of barnacle Balanus amphitrite, which is a major marine fouling and a potential invasive organism. Since the power used and treatment time for disinfection are economically, and practically, the most important parameters, the energy required to pulverize the larvae into pieces ≤30 µm was determined as a function of the acoustic power density. The present investigation suggests that an ultrasonic system operating at 20 kHz and 0.0975 W/cm3 can effectively pulverize barnacle larvae having length (~440 µm) and breadth (~350 µm) within 45 seconds using 0.1 mJ/larva of pulverization energy. It was also observed that following pulverization of the larvae, the bacterial abundance increased and the rate of release of bacteria was dependent on power level and treatment time, which in turn decided the pulverization rate and hence the rate of release of bacteria.

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.

In altricial mammals, mothers' care and attendance are essential for young to acquire survival skills. Despite the crucial importance of this early period for pup survival, not much is known about mother–pup behaviour and time allocation in the wild. To improve our understanding of the critical period of the sea otter development, a total of 240 30-minute focal follows of females with pups of different ages were conducted in four 6-hour-periods (dawn, day, dusk and night) from 4 June to 12 August 2008. Generalized linear models were used to investigate the impact of age, weather, tide and time of day on otters' behaviour. Pups significantly decreased resting behaviour and increased feeding, travelling, interacting and grooming behaviour with increasing age. Females with large pups fed and interacted significantly more, and travelled and groomed the pup less than females with small pups. Foggy conditions were associated with less resting on the water and increased travelling by pups. Tide did not appear to have an effect on sea otter behaviour. Grooming by pups occurred mainly during dawn in medium sized pups whereas large pups groomed themselves mostly during the day and night. Variations due to times of day tended to be apparent only in larger, i.e. older pups. Females and large pups were more active during the day. Mothers of smaller pups spent most of their active time travelling whereas females with large pups were mostly feeding. This study showed how sea otter females with pups adapted their behaviours as their pups grew and matured during the first months of life.

Habitat preference and spatial distribution of Guiana dolphins (Sotalia guianensis) in Norte Bay, southern Brazil, was studied from 2001 to 2005. Boat surveys (N = 91) were made to evaluate the spatial distribution of the dolphins. Seven habitat variables were integrated into a geographical information system, and habitat preference was tested using the ‘Neu method’ and a habitat index. The Guiana dolphins did not use all habitat types in the same proportion as were available. Areas used more intensively included, in order of importance: (1) areas with a steep sloping sea-floor; (2) areas further from urban areas; (3) areas further from mangroves; (4) areas near the mouth of the bay; (5) shallow water areas; (6) areas of clayey-silt sediments; and (7) areas close to shore. From 2001 to 2005 there was a shift in spatial distribution and habitat use by the dolphins. The low frequency of use of areas close to urban encroachment and its related impacts to the marine environment raises concern about the coastal habitat destruction. The Guiana dolphin may be considered a habitat specialist, despite its wide latitudinal distribution in the western Atlantic Ocean. The ecological niche of the species may be defined by a narrow strip of shallow coastal waters (mostly < 30 m) bordering the coastline. The shift in the spatial use was probably linked with changes in the abundance of important prey of the species and possibly was caused by the collapse of a fish stock in the study area region. Different habitats may favour different assemblages of prey and consequently different foraging strategies by the dolphins. Human-related habitat alterations throughout the range of this species are likely to affect dolphins' ecology in many ways and, thus, must be evaluated and mitigated to conserve their critical habitats.

The jumbo flying squid, Dosidicus gigas, support an important squid fishery off the Exclusive Economic Zone of Chilean waters. However, we only have limited information about their biology. In this study, age, growth and population structure of D. gigas were studied using statoliths from 533 specimens (386 females and 147 males) randomly sampled in the Chinese squid jigging surveys from 2007 to 2008 off the Exclusive Economic Zone of Chile. Mantle lengths (MLs) of the sample ranged from 206 to 702 mm, and their ages were estimated from 150 to 307 days for females and from 127 to 302 days for males. At least two spawning groups were identified, the main spawning peak tended to occur between August and November (austral spring group), and the secondary peak appeared during March to June (austral autumn group). The ML–age relationship was best modelled by a linear function for the austral spring group and a power function for the austral autumn group, and the body weight (BW)–age relationship was best described by an exponential function for both the groups. Instantaneous relative growth rates and absolute growth rates for ML and BW did not differ significantly between the two groups. The growth rate of D. gigas tended to be high at young stages, and then decreased after the sub-adult stage (>180 days old). This study suggests large spatial and temporal variability in key life history parameters of D. gigas, calling for the collection of more data with fine spatial and temporal scales to further improve our understanding of the fishery biology of D. gigas.

Six additional specimens (56–330 mm DW, 152–558 mm TL), including two embryos, of Brazilian deep-water skate, Rajella sadowskii, were used to supplement the original description which was based on eight specimens. The original description is considered sufficient, however, the range of some characters are enlarged, including some diagnostic measurements and counts characters. The description of adult fresh specimen, embryos, egg capsules, scapulocoracoid and the pelvis of this species are reported here for the first time, all collected on the Campos Basin off south-eastern Brazil, at depths from 1067 to 1353 m.

The white shark is known to inhabit the Gulf of California, but few published records exist for the most frequent localities of captures or sightings of this protected and relatively uncommon shark in Gulf waters. We have compiled and here report 38 records of white shark captures and reliable sightings for the Gulf. Records include individuals caught as by-catch by shrimp trawlers and gill-nets, and several sightings by divers or at fishing camps with corroborating photographs or sets of jaws (teeth). The main locations of occurrence were El Golfo de Santa Clara (13 records), followed by Santa Rosalía (4), and San Pedro Mártir and San Pedro Nolasco Islands (3 each). Presence of juveniles (<300 cm total length) was highest from January to May (10 records); whereas in July and October only two juveniles were recorded. Adults were more common from December to May (8 records); whereas from June to October there were fewer (5). Human induced threats and conservation of the white shark in the Mexican Pacific are briefly discussed.

On 30 September 2007, one specimen of Chili sea catfish Notarius troschelii was collected by a shrimp trawler on the continental shelf of the Mexican State of Nayarit. The fish, with a total length of 706 mm and a weight of 3910 g, constitutes a new record of maximum length and weight for this species.

The sighting of the brush-clawed shore crab Hemigrapsus takanoi on the western coast of northern Cotentin confirms the extension of this species into the western part of the English Channel. This new sighting remains enigmatic because the Normanno-Breton Gulf circulation patterns do not appear to promote natural transport of crab larvae from the Atlantic or from the eastern part of the English Channel. It has been suggested that the professional oyster transport could be the origin of this species' presence on this part of the French coast.

In the present study gut type was described and intestinal indices (i.e. mean gut length, relative gut length and Zihler's index) were estimated and compared for 58 fish species from the North Aegean Sea. A strong relationship between gut length (GL) and total length (TL) (significant relationships (P < 0.05) for 52 species) was found, whereas the hypothesis of the allometric growth of GL with TL was confirmed for 27 out of the 52 species. For the same TL, GL differs for species with different feeding habits (in omnivores > carnivores), as previously reported. Finally, for the same TL, GL also differs for species with different habitats (reef-associated > pelagic > benthopelagic > demersal) and gut types (Z-shaped with multiple loops > looped Z-shaped > Z-shaped >straight > convoluted > short with spiral valve).

Savalia savaglia (Anthozoa: Zoantharia) is an uncommon, large, arborescent, modular species best known from the western basin of the Mediterranean Sea, and recorded recently from the Canary Islands. During dives in the Ría de Arousa (Galicia, north-western Spain, north-eastern Atlantic), four colonies were seen at a depth of 26–29 m, and identified by morphological study, including the cnidome, and DNA sequencing. These new records extend considerably the distribution of the species. Given that S. savaglia lives in the north-west of the Iberian Peninsula, overlooked old records from the literature further north from the Bay of Biscay may be reliable.

An individual of the cowtail stingray (Pastinachus sephen) was identified at Ningaloo Reef, Western Australia as having a high number of parasitic leeches and gnathiid isopods primarily inhabiting its mouth, jaw and gills. It was underweight for its length and disc width when compared with other individuals of this species and its stomach was bloated and empty. It is proposed that the high density of these parasites directly led to the physical degradation and bodyweight of this individual. In addition to observing two previously undescribed hosts from this location, this is also a new locality record for this species of parasitic leech in Western Australia.

Larval stages of protozoeas II and III and zoea I of Aristeus antennatus were found in low numbers near the red shrimp fishing grounds off the Balearic Islands. The discovery of the larvae in the upper water layers has led to a proposed model of reproductive dynamics, in which newly hatched larvae perform an ontogenetic migration up through the water column to surface waters, where the larval stages develop. Data on the horizontal distribution of larvae presented, can contribute to an understanding of the dynamics processes of larval dispersal of the zoeal stages.

The spatial distribution, abundance and assemblage structure of the polychaetes community on the eastern coast of the Cap Bon Peninsula were studied at 25 sites. We found a total of 150 species belonging to 22 families, of which 47 new records and six families have been added to the Tunisian polychaetes fauna, such as Metasychis gotoi (Izuka, 1902), Aricidea cerrutii (Laubier, 1966), Bhawania goodei Webster, 1884 and Eunice tubifex Crossland, 1904. Among the families, Syllidae ranked first by number of species (14 species) and Onuphidae by number of individuals (25% of the total number of individuals). The cluster analysis identified five assemblages of sites that have a significantly similar composition. The five polychaete communities on the eastern coast of the Cap Bon Peninsula were mainly structured by environmental conditions and types of substratum.

This study defined the body weight/length relationship and an equation for body mass estimation using morphometric measurements on Amazonian manatees Trichechus inunguis (Mammalia: Sirenia). Total length (TL), maximum girth (MG) and body mass (M) were obtained from 91 captive Amazonian manatees (46 males and 45 females) of different ages, and TL and M were obtained from eight free-ranging Amazonian manatees (6 males and 2 females). The data were analysed by linear and multiple linear regressions. The maximum length and mass measured were 266.5 cm and 379.5 kg, respectively. The equation for body weight/length relationship was M = 0.00001070 * TL3.122 (r2 = 0.984) (Equation I) and no differences between sexes and between captive and free-ranging animals were found (P > 0.05). We calculated two more equations for mass estimation (Equation II: M = 0.00003284 * TL1.857 * MG1.106, r2 = 0.992; and Equation III: M = 1.506 + 0.00003477 * TL * MG2, r2 = 0.995), and the best equation (high correlation coefficient and low percentage of residues) was Equation III. Equation I provides the body condition of manatees, whereas Equation III is more accurate for estimating body mass. Both equations are important tools for management of captive and free-ranging Amazonian manatees.

Recent collection of the red alga Gloiocladia furcata from the north-eastern Atlantic coast of Spain has shown that this species does not only inhabit the Mediterranean as was previously thought. Here we present the first record for the Spanish Atlantic coast and moreover we show that the vegetative and reproductive structures of Atlantic specimens are similar to those of Mediterranean G. furcata. We review the herbarium material collected during the late 19th Century from the French Atlantic coast and discuss the presence of this species along the European Atlantic coast. The geographical distribution of this species on the Atlantic and Mediterranean coasts is reported.