Diet and food selection by small mammals in an old-growth Atlantic forest of south-eastern Brazil

Here we describe the stomach contents of nine small mammal species (seven rodents and two didelphid marsupials) co-occurring in an old-growth Atlantic forest area. For four terrestrial rodents, we also compared the importance of arthropods in the diet and the selection of arthropod groups by comparing consumption with availability. Small mammals and arthropods were sampled in a 36-ha grid containing 25 sampling stations spaced every 150 m, and 47 stomach contents were analysed. While plant matter was the predominant item in the stomach contents of two rodents (Oligoryzomys nigripes and Rhipidomys mastacalis), four species presented arthropods as the main food item (the rodents Brucepattersonius soricinus and Oxymycterus dasytrichus, and the marsupials Monodelphis n. sp. and Marmosops incanus) and three consumed more plant matter than arthropods, but had significant amounts of both items (the rodents Delomys sublineatus, Euryoryzomys russatus and Thaptomys nigrita). Our results suggest that differences in diet, coupled with differences in habit and microhabitat preferences, are important factors allowing resource partition among species of the diverse group of co-occurring terrestrial small mammals in Atlantic forest areas. Moreover, arthropods were not preyed opportunistically by any of the four terrestrial rodents, since consumption was not proportional to availability. Rather, selection or rejection of arthropod groups seems to be determined by aspects other than availability, such as nutritional value, easiness of capture and handling or palatability.

New terebellids (Polychaeta: Terebellidae) from northeastern Brazil

Four new species of terebellid polychaetes were collected at the Reserva de Desenvolvimento Sustentavel da Ponta de Tubarao, State of Rio Grande do Norte, northeastern Brazil. These species are Streblosoma patriciae sp. nov., Terebella leslieae sp. nov., Nicolea ceciliae sp. nov., and Pista alonsae sp. nov. All these species are herein described and compared with the morphologically most similar congeners.

New Species of Earless Lizard Genus Heterodactylus (Squamata: Gymnophthalmidae) from the Highlands of Chapada Diamantina, State of Bahia, Brazil

A new species of Heterodactylus is described based on two specimens obtained in the highlands of Chapada Diamantina, state of Bahia, Brazil. The new lizard is characterized by very elongate body and tail, absence of external ear opening, presence of moveable eyelids, absence of prefrontals and frontoparietals, a vestigial interparietal, 37-39 dorsal and 27-29 ventral transverse scale rows, 23-25 scales around midbody, six gular scale rows, and 10-11 and 14-15 fourth finger and fourth toe infradigital lamellae, respectively. The new species is most similar to Heterodactylus lundii from which it differs by the absence of contact between frontal and interparietal, by having wider than long parietals, smooth posterior dorsal scales, posterior ventral scales almost twice longer than wide, a lower number of scales around midbody, last supralabial in contact with the granules of the ear depression, and a more elongate body. The new species occurs about 1,100 km north of the northernmost known record of H. lundii. Species of Heterodactylus seem to be restricted to areas of cold climates associated with high latitudes and mountainous areas of eastern Brasil.

The genus Prosphaerosyllis (Polychaeta: Syllidae: Exogoninae) in Brazil, with description of a new species

In studies carried out off the north-eastern and south-eastern coast of Brazil, three species of Prosphaerosyllis were found: P. isabellae, which was already recorded for Brazilian waters; P. xarifae, a newly recorded species for the area; and P. brachycephala sp. nov., a new to science species. Prosphaerosyllis brachycephala sp. nov., is characterized by having swollen anterior part of the body, prostomium retractable within the peristomium and anterior segments, short antennae, short peristomial and dorsal cirri, and falcigers with short, unidentate blades throughout. All these species are herein described and compared to the most similar congeners.