Marine planarians were collected extensively from the Iberian Peninsula and Italy. As a result we provide new distributional records of six species of marine triclads, including the description of one new genus and species. The study increases substantially our knowledge of the distribution of this group of animals in Spain and reveals that even relatively well studied areas, such as Italy, still yield new species. In addition, we performed immunostaining studies of the nervous system of three of the species, which revealed the detailed organization of the main nerve cords and their branches. In the new species, the lateral nerve branches showed an arrangement that is different from that of the other species.

Cephalocarida is a rare and poorly known class of small benthic crustaceans, consisting of only eleven species belonging to five genera. Thus far, only one species (Hutchinsoniella macracantha) has been studied at molecular level. We report the partial sequences of two phylogenetically important mitochondrial genes (Cytochrome c Oxidase I and Cytochrome b) from the newly discovered Mediterranean species, Lightiella magdalenina. The genetic relationships between the two cephalocarid species are discussed.

Opisthoteuthis hardyi was originally described from a single male specimen caught near Shag Rocks (north-west of South Georgia) and no further specimens have been attributed to this species. During research fishing on the Patagonian slope to the south-east of the Falkland Islands 33 specimens of Opisthoteuthis were caught at depths ranging from 630 to 1391 m. Morphological measurements indicated that these specimens were conspecific to the holotype of O. hardyi. The mitochondrial gene 16S rDNA was sequenced from two of these specimens and compared with a published sequence of the holotype and other Opisthoteuthidae to confirm the morphological data. This extends the geographical and bathymetric range of the species, which spans the Antarctic Polar Front. We also expand the original description, providing details of the digestive system and of the female reproductive system, with preliminary estimates of fecundity.

Karyotypes of the hermaphroditic polychaete Hediste limnicola were examined using an air-drying method and genetic material prepared from regenerating tail and newborn juveniles. Materials were obtained from a lineage of cultured worms originating from Watsonville Slough (California, USA) and maintained for six years in the laboratory. Giemsa-stained preparations were analysed by a computer-assisted image-analysing system for the identification of each chromosome pair. A diploid chromosome number of 26 was obtained from well-spread metaphase chromosomes of mitotic cells, consisting of metacentric (N = 11), submetacentric (N = 1) and telocentric (N = 1) chromosomes. It is possible that hermaphroditism in this species evolved through loss of a pair of sex chromosomes, which are present in closely related congeneric species.

The wedge sole (Dicologoglossa cuneata, Moreau 1881) is a commercially important species for the artisanal fleet operating off the south-western Iberian Peninsula. During 2004 and 2005 a study was undertaken aiming to provide a scientific basis for management. Data collection included information on aspects of the fishery, spawning season, size at first maturity, tangle and gill-net selectivity. Seven nominal mesh sizes were used (40, 45 and 50 mm tangle nets and 40, 50, 60 and 70 mm gill-nets). Spawning lasts from December to June, with peaks in March and May. Length at first maturity for females was estimated at 18.5 cm. Catch rates decreased sharply with increasing mesh size, with tangle nets providing the highest yields. The log-normal selectivity model provided the best fit for specimens that were wedged. The higher catch-per-unit-effort of the smaller mesh sizes and the modal length of the fitted selectivity curve being below the size-at-maturity for wedge sole, suggests that the 50 mm nominal mesh size tangle net is the most appropriate for ensuring the fishery sustainability. Nevertheless, the minimum legal size should increase to at least 18 cm and a time–area closure should be implemented off the Guadiana River mouth.

Social organization is an important attribute of the animal society. We describe the social structure of a bottlenose dolphins population living in Panama City, a seaside resort located on the north-west coast of Florida. Study was conducted with 46 individuals. Dolphins are associated on average half weight index of 0.11. Preferred long-term associations are observed. The proportion of the non-zero association indices suggests that some dolphins seem to avoid others. Associations between and within sex-classes were investigated using only dolphins of known sex and observed at least 4 times. Highly significant differences are found in associations between and within sex-classes (Mantel test, t = 3.7987; P = 1); indeed, male associations are stronger than between inter-sexual associations or between females only. Sociogram of males reveals a complex network with strong associations between pairs or trios that reach up to 0.97, whereas female associations are lower than males. The cluster analysis shows no clear division in the social organization of bottlenose dolphins in Panama City, except for dyads, triads and their multiple networks. The population structure seems to be temporally stable over the study and constant companionships are observed in the dolphin population in Panama City.

A collection of over one hundred specimens of Syllidae (Polychaeta) from the Arctic and sub-Arctic regions has been examined and identified. The specimens were obtained from 26 stations in the Barents Sea, some Norwegian fiords and localities of the northern North Sea. A total of 21 species were identified; three species (Myrianida langerhansi (Gidholm, 1967), Syllides longocirrata Örsted, 1845 and Sphaerosyllis taylori Perkins, 1981) are new reports for the Arctic Ocean; 2 species are new to science, Streptodonta exsulis sp. nov. and Trypanosyllis troll sp. nov. Streptodonta exsulis sp. nov. have 4 thick, distally strongly knobbed aciculae on each anterior parapodia, shifting to a single, slender acicula on posterior parapodia; falcigers and pseudospinigers distally bidentate; and pharyngeal tooth located centrally and relatively close to anterior rim of pharynx. Trypanosyllis troll sp. nov. have 2, occasionally 3 straight aciculae in parapodia protruding out from parapodial lobes; falcigers bidentate; and body surface densely covered by numerous, small papillae. Based on the description of these 2 new species, some modifications are proposed in the diagnoses of the genera Streptodonta San Martín & Hutchings, 2006 and Trypanosyllis Claparède, 1864.

The burrowing brittle-star Acrocnida brachiata has so far been regarded as a single, easily identifiable species. Recent studies showed habitat-related differences in maximum size, life span, breeding time and recruitment between intertidal and subtidal populations, which at first were attributed to environmental effects on individuals within the same species. Molecular data, however, strongly suggested the existence of two distinct lineages and ultimately two cryptic species with clear bathymetric segregation. Morphological evidence had so far not been presented, because any differences were interpreted as intraspecific variation. We collected A. brachiata from intertidal and subtidal habitats at the coast of Brittany, France, and examined 15 specimens of each group externally by SEM. A key character of A. brachiata is that the scales at the edge of the disc and on the ventral side are conically enlarged. Intertidal individuals showed a sparser disc scalation, more spine-like than conical ventral disc scales and spatulate, distally widened arm spines. In addition, we dissected several specimens of different size and examined the internal skeleton by SEM. The oral plates showed a rib-like structure on their abradial face that differs between individuals from either habitat. Subtidal specimens have fewer ribs than intertidal ones. These consistent differences support the existence of two species within A. brachiata. To describe the second species, we needed to establish the identity of A. brachiata. We describe a neotype, because no type material has been preserved since it was first described; it corresponds mainly to subtidal samples. The new species is described as Acrocnida spatulispina sp. nov. The taxonomic status of Acrocnida has been debated over the years with reference to its close affinities with Amphiura chiajei. We compared the species of Acrocnida with A. chiajei and Amphiura filiformis and found that Acrocnida is indeed morphologically similar to A. chiajei, among other characters by a similar oral plate structure, whereas A. filiformis differs greatly from Acrocnida as well as A. chiajei. Most strikingly, it has a different type of oral plate. These findings indicate that fundamental taxonomic changes may need to be made in the family Amphiuridae in the future.

The morphology and taxonomy of a new species of otoplanid (Plathelminthes: Rhabditophora: Proseriata) is discussed. Otoplana proxima sp. nov., collected at Marina di Bibbona (Livorno), presents the typical morphological peculiarities of the subfamily Otoplaninae, but clearly differs from the previously described species with regard to the organization of the genital organs. The new flatworm appears more similar to Otoplana intermedia, but differs sharply in its body length and male copulatory organ made up of 23–24 pliable spines (42–70 μm long) characterized by a forked tip and a canaliculated proximal end.

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.

Eight populations of Caprella penantis, three of Caprella dilatata and two of Caprella andreae, collected from different sites all over the world, were selected for genetic study. Thirteen primers were tested, and the phenogram, based on the similarity coefficient of Nei & Li and the UPGMA method, separated clearly C. dilatata and C. andreae from the populations of C. penantis, supporting the validity of these three species, traditionally considered altogether under the old ‘acutifrons’ complex. Populations of C. penantis (including, at least, forms simulatrix, testudo and lusitanica) from Spain, Portugal, Morocco, Japan and Brazil were clustered together in the RAPD analysis, indicating that, probably, all the specimens of C. penantis could belong to the same species, in spite of morphological variations in the pleura, gills, robustness and presence/absence of proximal projection in adult male gnathopod 2 propodus. The only population which showed genetic differentiation within the C. penantis complex was the form gibbosa from Coquimbo, Chile. Future analysis based on different molecular approaches (mtDNA, 18S rRNA, ISSR) and additional material from other world areas, should be conducted to confirm these results.

During an investigation devoted to characterize all the Orbiniidae polychaete species present in the Iberian Peninsula, several individuals previously identified as Scoloplos armiger showed to actually belong to Scoloplos haasi, a species to date considered endemic from Israel. The comparison with the holotype deposited in the British Museum of Natural History confirmed the identification. This record of S. haasi is not only a new one for the western Mediterranean but also the first one out of its original locality, extending largely westwards the geographical range of the species.

The behavioural patterns of humpback whales are known to vary according to the social function of individuals in a group. To identify behavioural patterns related to specific group compositions, we observed events and behavioural states of humpback whales during research cruises in the Abrolhos Bank, Brazil, in the reproductive seasons from 1992 to 2003. We monitored 3022 groups and found a predominance of competitive groups without calves, when compared to competitive groups with calves. A Bayesian network analysis supplied occurrence probabilities for the behaviours analysed, indicating higher probabilities of occurrence for the behavioural patterns designated travelling and socializing. The model, generated from a binomial logistic regression, was able to predict competitive groups in association with the occurrence of the following aggressive behaviours: head-lunging, trumpet and bubblestreams. This study suggests the existence of behavioural patterns associated with specific group compositions and reinforces the concept that there is a clear-cut relation between competitive groups and the occurrence of aggressive behaviours. The preferential association of males to females with high reproductive potential for the following year (i.e. females without a calf) was also identified.

Keratose sponges have no spicules and limited robust morphological characters, causing severe problems for taxonomic classification. Single-strand conformational polymorphism (SSCP) analysis of PCR amplified internal transcribed spacers (ITS) of nuclear ribosomal RNA (rRNA) genes was used to elucidate speciation patterns in marine sponges of the genus Aplysina. In this study, Aplysina species with non-ambiguous traditional morphological alpha taxonomy were used to generate standard SSCP-ITS patterns, which were compared with patterns from alleged new species. Our results show that ITS-SSCP patterns allowed the differentiation of Aplysina sponges, demonstrating the advantage of a method that explores the secondary structure compared to direct sequencing.

Crabs from the Mithrax–Mithraculus species complex are known for their diversity of lifestyles, habitats, and coloration. This group includes small, colourful, symbiotic species and much larger, reef-dwelling crabs targeted by fishermen. The evolutionary relationships between the species within this complex are not well-defined. Previous studies based upon morphological characters have proposed the separation of this complex into two genera (Mithrax and Mithraculus), but cladistic analyses based upon larval characters do not support this division. A molecular phylogeny of the group may help to resolve this long-standing taxonomic question and shed light on the ecological conditions driving the diversity of these crabs. Using a 550-bp alignment of the 16S rRNA mitochondrial DNA segment we examined the phylogenetic relationships between 8 species within the Mithrax–Mithraculus complex native to the Caribbean. The resulting phylogeny indicates that this complex is paraphyletic, as it includes the genus Microphrys. The analyses revealed a well-supported, monophyletic group containing four species of Mithraculus (M. cinctimanus, M. coryphe, M. sculptus and M. forceps) and supported one pair of sister species from the genus Mithrax (M. caribbaeus and M. spinosissimus). No complete segregation of species, according to genera, was evident, however, from tree topologies. Bayesian-factor analyses revealed strong support for the unconstrained tree instead of alternative trees in which monophyly of the two genera was forced. Thus, the present molecular phylogeny does not support the separation of the species within this complex into the genera Mithrax and Mithraculus. A review of the literature demonstrated considerable phenotypic variation within monophyletic clades in this group.

Eophliantidae are poorly studied marine algal-dwelling amphipods with a wide distribution. A new species was found to excavate burrows across the main stem of Carpophyllum maschalocarpum (Turner) Grev. in the New Zealand subtidal, and a detailed morphological description of this amphipod is given. Bircenna macayai sp. nov. can be distinguished from other Bircenna species by a combination of the following characters: bilobed coxa 1, merus and carpus of pereopods 5–7 strongly extended posteriorly, crenulate basis of pereopod 7 and smooth posterior margin of epimeron 3, pereopod 7 basis longer than wide. A key to the fourteen world species of Eophliantidae is provided. Taxonomy, evolutionary sequences, functional morphology and biogeography of the Eophliantidae are briefly discussed. New Zealand and Australian shallow waters show the highest species diversity of Eophliantidae, containing both species bearing plesiomorphic and highly derived characters, suggesting that Australasia is an evolutionary centre for this amphipod family.

Molecular analysis has become a powerful tool in cetacean ecology since it supports efficient conservation policies. Remote biopsy sampling is the most efficient method to obtain epithelial material for analysis purposes; however, as an intrusive technique it presents inherent costs, evidenced by behavioural reactions. Clarifying which factors influence these responses is essential to assess its impact and prevent possible long-term effects. For eleven winters, samples from humpback whales were collected in the Abrolhos Bank, the main breeding ground of this species in the western South Atlantic. We analysed the influence of several characteristics of the shot, vessels, groups and behaviour on the frequency and intensity of the whales' response. The majority of biopsied whales did not show any detectable response. Among those that responded, a low-level category of reaction was most frequent. The use of larger boats resulted in less intense responses. Responses were influenced by group size and behavioural state: large groups, which were involved in aggressive mating behaviour, reacted less frequently than smaller groups. Females with calves showed less intense reactions than non-lactating females. The behaviour of the animals prior to and during the boat approach also affected their response: resting whales responded more intensely than whales involved in social or travel activities. Comparison with previous studies confirmed that reactions vary in intensity according to location: whales biopsied in feeding grounds responded with more intensity than those in breeding grounds, which in turn responded more intensely than whales in migration. This study reinforces existing evidence that biopsy sampling is unlikely to have long-term effects and can thus continue to be used as one of the main tools to access information which is vital for conservation.

The population genetic structure of the mantis shrimp, Oratosquilla oratoria, in Hong Kong waters was determined using 923 base pairs of mitochondrial DNA control region sequences. Samples were collected from six localities including the open-waters and sheltered bays in both the eastern and western waters of Hong Kong. Twenty-seven haplotypes were detected in 99 individuals. A high overall haplotype diversity (h = 0.886), with a low nucleotide diversity (π = 0.0026), was observed, and the haplotype minimum spanning network suggested that rapid expansion might have occurred among the total stomatopod population. Genetic homogeneity was observed over a meso-scale distance (80–100 km) whilst there were significant genetic differentiations between all pairs of the six samples. Partition of genetic variability based on hydrographic conditions did not reveal significant differentiations between: (1) eastern and western waters; and (2) open-waters and sheltered bays; but showed high levels of variation both within groups and within samples. Unexpectedly, genetic distance did not correlate with hydrographic distance among the samples. Results demonstrated a genetic patchiness pattern of O. oratoria in Hong Kong waters that may be attributable to the interplay between hydrographic conditions (e.g. salinity) and the species' life history traits.