Occurrence, residency patterns and habitat use of the bottlenose dolphin, Tursiops truncatus truncatus, on two Marine Protected Areas in Southeastern Brazil.

The common bottlenose dolphin, Tursiops truncatus, is widely distributed. However, information about its ecology and behavior in Brazilian waters is scarce especially about the 'offshore' ecotype, an Evolutionarily Significant Unit in the Southwest Atlantic. We report for the first time the occurrence, behavior and habitat use of bottlenose dolphins Tursiops truncatus truncatus, in two Marine Protected Areas (MPA) in Cabo Frio coast, Brazil. There were fifteen sightings of different groups throughout the year. An overall of 429 individuals were photo-identified. 90.7% dolphins did not present a degree of residence, 1.4% dolphins were considered with high residency to the area, 5.8% medium and 2.1% low. Our habitat use map indicated dolphins were more common off ~10km from Cabo Frio municipality and between depths around 20-70m. Bottlenose dolphins on Cabo Frio coast were more frequently observed performing travelling, followed by foraging and socio-sexual behavior. Group sizes varied from three to 120 individuals. Larger groups were observed when travelling and foraging. Despite the existence of two local Marine Protected Areas, the fast human development in Cabo Frio may threaten this important area for bottlenose dolphins in terms of food resources and shelter from predators.

Sandy beaches: state of the art of nematode ecology.

In this review, we summarize existing knowledge of the ecology of sandy-beach nematodes, in relation to spatial distribution, food webs, pollution and climate change. We attempt to discuss spatial scale patterns (macro-, meso- and microscale) according to their degree of importance in structuring sandy-beach nematode assemblages. This review will provide a substantial background on current knowledge of sandy-beach nematodes, and can be used as a starting point to delineate further investigations in this field. Over decades, sandy beaches have been the scene of studies focusing on community and population ecology, both related to morphodynamic models. The combination of physical factors (e.g. grain size, tidal exposure) and biological interactions (e.g. trophic relationships) is responsible for the spatial distribution of nematodes. In other words, the physical factors are more important in structuring nematodes communities over large scale of distribution while biological interactions are largely important in finer-scale distributions. It has been accepted that biological interactions are assumed to be of minor importance because physical factors overshadow the biological interactions in sandy beach sediments; however, the most recent results from in-situ and ex-situ experimental investigations on behavior and biological factors on a microscale have shown promise for understanding the mechanisms underlying larger-scale patterns and processes. Besides nematodes are very promising organisms used to understand the effects of pollution and climate changes although these subjects are less studied in sandy beaches than distribution patterns.

The relationship between sandy beach nematodes and environmental characteristics in two Brazilian sandy beaches (Guanabara Bay, Rio de Janeiro).

We investigated if the differences in density and nematode communities of intertidal sediments from two Brazilian sheltered sandy beaches were related to environmental characteristics. The upper tide level (UTL) and the low tide level (LTL) of both beaches were surveyed in January (austral summer) and June 2001 (austral winter) during low-spring tides, by collecting samples of nematodes and sediments. Differences in density between beaches, tidal level and seasons, and nematode community structure were investigated. Sediments from both beaches were composed of medium to very coarse sand. The highest nematode densities were found at the UTL, and significant differences between beaches, tidal levels and months were found. A total of 54 genera were found and the genera composition on both sheltered beaches was similar to other exposed worldwide sandy beaches. The density and structure of the nematode community at both beaches clearly varied along the spatial and temporal scales. Gravel percentage was the most important variable explaining the spatial distribution of the nematodes, determining the four sub-communities; this suggests that the sediment characteristics influence the nematode community, rather than physical hydrodynamic forces. Temperature and salinity were suggested to be important variables affecting the temporal variation.

Taxonomic review of Thoracostomopsidae (Nematoda, Enoplida): state of the art, list of valid species and dichotomous keys.

Thoracostomopsidae is a family of free-living marine nematodes that has three subfamilies (Thoracostomopsinae, Trileptiinae and Enoplolaiminae). Most species descriptions within this family are very old and lack indication of important morphological details, so this article aims to fill this gap in the literature. This taxonomic review provides a list of all valid species, as well as species inquirenda, nomina nuda and synonyms, for each genus. Our review recognizes 16 valid genera, 193 valid species, 47 species inquirendae and three species as nomen nudum. Additionally, taxonomic dichotomous keys were constructed, modified or updated for each genus, as well to the subfamilies, using the most important diagnostic characters.

A new species of Cephalanticoma (Enoplida: Anticomidae) from Brazilian coast (Atlantic Ocean), with emended diagnosis and dichotomous key to the genus.

A new species of the genus Cephalanticoma is described for the Atlantic Ocean in the Potiguar Basin off the continental shelf of northeast Brazil. Cephalanticoma rugatusa sp. n. is characterized by bearing head capsule ending on the level of amphideal fovea, a tubular precloacal supplement and two rows of thin precloacal setae. Cephalanticoma rugatusa sp. n. differs from all other species of the genus by having a precloacal cuticular papilla in front of the cloaca and a cuticular transversal wrinkle which extends from the papilla elevation to the conical-cylindrical portion of the tail occupying both subventral regions. An emended diagnosis and a dichotomous key to species based on both genders are provided.

The state of the art of Chromadoridae (Nematoda, Chromadorida): a historical review, diagnoses and comments about valid and dubious genera and a list of valid species.

Chromadoridae is a widespread family of mostly free-living marine nematodes. This systematic review provides for each genus: a historical background, an updated diagnosis and a list of species. Our review recognizes 37 valid genera, 395 valid species, 57 descriptions without enough morphological information for accurate identification (species inquirenda) and 10 species incerta sedis. We also recognize 21 species as nomena nuda. Additionally, polytomous keys were constructed for the subfamilies and for the genera of the three major subfamilies (Chromadorinae, Euchromadorinae and Hypodontolaiminae) using the most important diagnostic characters. A phylogenetic analysis based on rDNA sequences of species available in the GenBank was also conducted. Phylogenetic trees based on the 18S and 28S rDNA confirmed the classification into three subfamilies (Spilipherinae, Hypodontolaiminae and Chromadorinae), despite the absence of defined synapomorphies. Phylogenetic relationships at lower taxonomic level are problematic given the large number of sequences not identified to species level.