The waters of La Réunion, a French island located in the south-western Indian Ocean, have never been investigated for cetacean diversity. Dedicated daily surveys were conducted in 2004–2007 to assess cetacean diversity off the western and southern coasts of the island. A total of ten species was observed during the survey period, including two baleen whales and eight odontocetes. Four additional species that had not been observed at sea were reported stranded. The most frequent delphinid species were the Indo-Pacific bottlenose, the spinner and the common bottlenose dolphins, which were observed year-round. Photo-identification data showed a high recapture rate of Tursiops aduncus, strongly suggesting a resident population. The humpback whale uses the coastal waters of La Réunion seasonally, during winter. The high proportion of mother–calf pairs indicated that La Réunion might represent a breeding area for this species. Pantropical spotted dolphin, melon-headed whale and Fraser's dolphin were sighted at a medium frequency, in offshore waters, and tended to favour the southern part of the island. Three coastal species were frequently using the newly created Marine Protected Area (MPA), supporting the view that cetacean conservation issues have to be included in the MPA management plan currently in progress.

The diet of the monkfish Lophius gastrophysus is described based on the analysis of stomach contents, for the south-western Atlantic from samples landed in the fishing port of Niteroi, Rio de Janeiro state, Brazil, from April 2004 to March 2006. Feeding intensity, measured as the presence or absence of contents in stomachs, and differences in the items' composition were analysed by sex, size-class and season. High feeding intensity predominated for females >32 cm and for males <31 cm. There was no seasonal pattern in the occurrence of full or empty stomachs. The most important category in the diet was fish with 25 identified species. Dactylopterus volitans showed the highest alimentary index value, mainly because of the feeding of juvenile monkfish. The second most important category was Mollusca, represented mainly by squid. No relationships between predator- and prey-lengths and weights were observed; but there was a tendency to consume light and small prey independently of the size of the monkfish.

The study of living Halecium halecinum colonies revealed a new case of zooid polymorphism. Besides the ordinary hydranth, the polyp devoted to feeding, this species is provided with a second kind of polyp, differing only slightly in structure and morphology but most conspicuously in its behaviour. It is named ‘extensible polyp’ in reference to its great extensibility and the resulting filiform shape. There are slight differences in the tentacles: lower number, shorter length, thicker diameter, and the tip slightly swollen and rounded instead of tapering. Their large microbasic mastigophores are abundant and evenly distributed, while the hydranth has a few large ones only on the oral side but has otherwise numerous small ones. When extended and at rest, the tubular column is much longer than that of the hydranth and not delimited from the head of the polyp by a bulge followed by a constriction. Behavioural differences are its capacity to coil and bend during extension and thus being able to move in all directions and exploring a large volume of seawater, and also its ability to produce regional swellings (peristalsis) and to contract by folding and bulging though still extended. Besides a probable role in defence, the extensible polyp exhibits an excretory function and it could also have sensory functions. The extensible polyp type is not classified as a nematophore because it has a functional gastrovascular cavity and a mouth. Polyp dimorphism (hydranth/extensible polyp) is reported in one more halecid and two sertularids.

The life histories of Plecoglossidae and Osmeridae fish collected from Japanese fresh, brackish, and seawaters were studied by examining the strontium (Sr) to calcium (Ca) ratios in their otoliths. The Sr:Ca ratios in the otoliths changed with the salinity of the habitat. The fish living in a freshwater environment showed consistently low Sr:Ca ratios throughout the otolith. The fish were identified as a standard freshwater type. In contrast, fish collected from the intertidal zone showed higher otolith Sr:Ca ratios than those in the standard freshwater type, and the ratios fluctuated along the growth phase. In the present study, in addition to the representative migration pattern reported previously, other migration patterns were found to show consistently high Sr:Ca ratios throughout the otolith in several Osmeridae fish. Those results indicate that these fish have a flexible migration strategy with a high degree of behavioural plasticity and an ability to utilize the full range of salinity throughout their life history.

The blackmouth catshark, Galeus melastomus presents a wide Atlanto-Mediterranean distribution, and is commonly captured off the Languedocian coast (southern France, northern Mediterranean). The males and females sexually matured between 510–550 mm and 520–610 mm total length (TL), respectively. The largest male and the largest female were 620 mm and 640 mm TL, respectively. There was a significant relationship of total liver mass vs TL between males and females. The diameter of the largest yolky oocytes ranged from 15 to 18 mm (16.5 ± 2.7). Production of egg cases was observed throughout the year, except in September. Egg cases had between 36 and 50 mm (mean: 45.3 mm ± 3.9) in length without horns, and between 14 and 21 mm (18.2 mm ± 1.4) in width. Fecundity remained difficult to assess; an estimation based on production of egg cases enabled us to consider 93 egg cases per year as a maximum.

I observed shark mackerel demonstrating multiple search and attack strategies. Strategies were categorized as three distinct types: (1) a linear search by single or groups of fish along reef features; (2) ambush from a stationary position on the seafloor; and (3) ambush from resting schools of co-occurring predators. Together these strategies were consistent with both information-sharing and producer–scrounger models of group foraging and indicate significant flexibility in individual fish foraging behaviour based on proximate conditions.

This study used Monte Carlo methods to generate simulations that considered the effort distribution to determine the locations of significant aggregations of cetacean sightings inside the northern Pelagos Sanctuary (north-western Mediterranean Sea). For three years, monitoring has been conducted from five motor vessels covering about 30,050 km. The most frequently encountered species were the striped dolphin Stenella coeruleoalba representing 64.7% of all sightings, the fin whale Balaenoptera physalus (17.0%), Cuvier's beaked whale Ziphius cavirostris (9.9%), Risso's dolphin Grampus griseus (4.3%) and the sperm whale Physeter catodon (2.2%). Sightings' positions and effort coverage were distributed over a grid of 5′ longitude and 5′ latitude. Spatial concentrations of sightings were analysed according to the distribution of effort to identify ‘hotspots’ (locations where the species occurred at a significantly greater frequency than expected), and ‘coldspots’ (locations with a significantly lower frequency than expected). Most fin whale hotspots (14) were located on the bathyal plain between 2000 and 2500 m, four hotspots were around the 1000 m isobaths, and one is located close to the seamount off Genoa. Fin whale coldspots were mainly along the coast. Striped dolphin hotspots were widely distributed over two main areas, in waters with depths between 2000 and 2500 m and at the continental slope; coldspots for this species were also mainly along the coast in the northern part of the study area. Many hotspots were found in the Genoa Canyon, and hotspots of striped dolphins, Cuvier's beaked whales, sperm whales and Risso's dolphins overlapped in this region. Some of the hotspots of Cuvier's beaked whales were identified at the seamount in the study area, where no other species was sighted frequently. Risso's dolphin hotspots were mainly near the 1000 m isobath. For sperm whales, several hotspots were identified: three associated with steep slope features (such as canyons or the continental slope), and one was in the centre of the flat area of Pelagos where the depth is 2500 m. This study highlights the ecological importance of particular locations inside the Pelagos Sanctuary—locations that should be protected from anthropogenic degradations for marine mammal conservation.

Food of Seriola lalandi was mainly composed of juveniles of horse mackerel (Trachurus lathami) (%IRI = 99.66) showing the species as carnivorous feeders predating on small pelagic organisms.

A creeping movement, which often results in clockwise or counterclockwise bodily rotation, is described for ordinary zooids of two species of bivalve-inhabiting hydrozoans, Eutima japonica Uchida and Eugymnanthea japonica Kubota, attached to artificial hard substrata (polystyrene and glass) in the laboratory. Time-lapse video recordings furthermore showed that the non-transparent half of the flat, ellipsoidal pedal disc always faces forward during this motion, with no lateral or backward creeping during either day or night. Because an ordinary zooid generally crept in a circle of small radius, the zooid's body rotated as the creeping proceeded. One full rotation of a zooid of either species took about 5–6 hours on average at 21–25°C. The direction of rotation of an individual zooid was nearly constant irrespective of developmental state, this being true for zooids with or without a medusa bud on the hydrocaulus or a daughter zooid on the pedal disc, those with a normal or a double hydranth, or those consisting of a bare hydrocaulus. Asexually produced tiny daughter zooids quickly became well separated from their mother zooids. The attachment site of the latter did not shift much as they rotated, but daughter zooids and other tiny free zooids creep along a nearly straight line, thereby markedly shifting their position. This may contribute to the prevention of crowding of zooids in the restricted space between soft body parts in the host bivalve's mantle cavity.

In order to determine if eastern Pacific green turtles (Chelonia mydas) exhibit feeding preferences samples of recently ingested food items were compared to the food resources available in the marine environment where C. mydas congregates. Stomach samples were collected by conducting gastric lavage and, at the same time, vegetation transects were conducted during spring and winter. Green turtles in our study selectively consumed seaweeds, with Codium amplivesiculatum and Gracialaria textorii as preferred species. Differences in the consumption of species were found across the two mentioned seasons and were consistent with changes in the availability of different algae species in the environment. Based on these results, it is recommended that sea turtle conservation plans along the Baja California Peninsula include Pacific coastal mangrove channels with a high diversity of algae species as priority areas for protection.

The reproductive biology of the Jenyns's sprat Ramnogaster arcuata in the Río de la Plata area was studied using macroscopic and histological analysis of ovaries. Samples were collected during two research surveys carried out in June 1998 and June 1999. In addition monthly occurrences of this species from historical data were analysed. Jenyns's sprat specimens were mainly observed in open waters of the estuary during winter months. Most of the females collected during June 1998 and 1999 were in the spawning stage. This pattern differs from fish that reproduce in the estuarine waters of the Río de la Plata, which spawn during spring and summer. These results suggest that conditions of productivity and larval retention in the estuary also remain during winter months. This characteristic might be useful for R. arcuata larvae in avoiding competition with other estuarine spawners. Jenyns's sprat is a multiple spawner with indeterminate annual fecundity. A preliminary estimate of spawning frequency (N = 220) indicated a daily percentage of females with postovulatory follicles of 17.35%, which suggests that this species spawns on average once every six days. Batch fecundity, estimated from counts of hydrated oocytes from 40 females, ranged from 669 to 2026 hydrated oocytes in 1998 and from 570 to 1830 hydrated oocytes in 1999. Batch fecundity was fitted to a linear function of total body weight (without ovary) in 1999. Mean relative fecundity was 234 hydrated oocytes per female gram (ovary free) in 1998 and 155 hydrated oocytes per female gram (ovary free) in 1999, and no significant relationship was observed between this parameter and female size. The dry weight of 100 hydrated oocytes ranged between 3.9 and 6.3 mg, these values being significantly higher than those estimated for other species of the Río de la Plata estuary.

This paper presents data on the incidental catch of sea turtles in both the Brazilian exclusive economic zone and adjacent international waters (both areas are located mainly in the south-western Atlantic) by Brazilian commercial pelagic longliners targeting swordfish, tuna and sharks. Data were obtained by on-board observers for 311 trips carried out in 2001–2005, totalling 7385 sets and 11,348,069 hooks. A total of 1386 sea turtles were incidentally captured in the five years (some of them were considered dead at capture): 789 loggerheads (Caretta caretta), 341 leatherbacks (Dermochelys coriacea), 45 green turtles (Chelonia mydas), 81 olive ridleys (Lepidochelys olivacea) and 130 of unknown species. Taking into account the distribution of the fishing effort in the study area and the incidental catch of sea turtles, four regions were highlighted for the analyses: Zone 1 is located off the northern Brazilian coast; Zone 2 is located off the central Brazilian coast; Zone 3 is the region off the southern Brazilian coast; and Zone 4, located in the open sea almost totally within international waters, is the region around a chain of undersea mountains known as the Rio Grande Rise (Elevação do Rio Grande). There is no information on the origin (nesting areas) of the captured olive ridleys, but there is some evidence, obtained through genetic and demographic analyses, that loggerheads, leatherbacks and green turtles inhabiting the open ocean around Brazil originate from nesting areas in several countries. Together with the fact that the south-western Atlantic is fished by longliners again from several countries, this places the conservation of sea turtles in that part of the ocean in an international context. Some conservation actions carried out by Brazil concerning the interaction between pelagic longlines and sea turtles in the study area are described.

The auto-fluorescence patterns of the medusae observed under a fluorescent microscope with blue light excitation allows to distinguish two species of Eugymnanthea, this even when they are still attached to the hydroid as small medusa buds despite the occurrence of a sex-dependant pattern in E. japonica. A total of four distribution patterns of green fluorescence, including non-fluorescence, could be found. Three of them are found in E. japonica, called ‘subumbrellar fluorescence type’ except for non-fluorescence, while another type is found in E. inquilina, called ‘umbrellar margin fluorescence type’. During the short life of the medusa the latter type remained invariable for up to six days in E. inquilina, while the pattern observed for up to seven days in E. japonica changed sometimes, but it always remained distinguishable from the pattern found in E. inquilina. Therefore, the fluorescence pattern is a reliable taxonomic character. Fluorescence was not found in unfertilized eggs, planulae 2–8 days old, parthenogenetically produced larvae, or in the hydroids of the two species. The auto-fluorescent and possible bioluminescent tissues of these Eugymnanthea medusae could have some unknown biological significance.

The present work uses daily checklist data from whale-watching to study basic aspects of cetacean ecology. Data in the Azores consists of a simple daily list of all species sighted by boats, with no additional information. The Azorean whale-watching activity is described and sources of variation related to data collection are debated. A data-set from one whale-watching company is analysed from 2001 to 2006, from April to October (tourism season). The first four years were used to describe frequencies in the area, and maximum and minimum regional sea surface temperatures for nineteen cetacean species, based on remote sensed data. Several species were present throughout the season, while for others, results indicate transient habits in the study area (Balaenopterids, Globicephala sp., Pseudorca crassidens, Orcinus orca and Hyperodoon ampullatus). Reservations were made relative to small size and evasive species. Sighting frequencies on temperature classes in 2005 and 2006 were used successfully in an experimental approach to study delphinid simpatry. The simplicity of data was overcome by the diversity of sighted species and the dimension of the time scale. Daily checklist is a low cost useful source of information mainly for large cetaceans that should keep being registered.

Little is known about cetacean communities around La Palma Island. Therefore, and in order to determine the presence and distribution of the cetacean species on its west coast, daily censuses were carried out from November 2003 to April 2005. The platform used was a whale watching vessel certified by the Canary Government. Data collected included time, position, species identity, group size and, in some cases, the presence of calves and/or any other outstanding parameter. During the study period, 570 sightings were made, with a mean sighting success of 1.7 sightings per day, showing a high cetacean presence in the area. Thirteen species and one genus (Globicephala spp.) were positively matched, three of them included in the Mysticeti suborder and the other ten in the Odontoceti one. The four most sighted species, in decreasing order, correspond to Tursiops truncatus, Steno bredanensis, Globicephala spp. and Stenella frontalis. Diversity of sighted species shows a moderate peak during spring time, which is in agreement with the presence of occasional species. Most sightings were located off the central west coast of the island, exceeding 1.5 nautical miles. This is particularly outstanding in relation to Franja Marina de Fuencaliente SCI, where 90% of all sightings were located outside its boundaries. High cetacean presence and diversity off the west coast of La Palma Island seem to be connected with oceanographic and ecological features. Results gained provide, for this region, baseline data on cetacean populations and a useful tool in conservation plans.