The Caatinga is the largest seasonal tropical dry forest with extreme environmental and meteorological conditions. It harbours many phytophysiognomies and vegetational units, but bat fauna is poorly known in many regions. We analysed the structure of bat assemblages by mist-netting during 99 nights in seven habitats throughout six sites in the northeasternmost region of the Caatinga in Rio Grande do Norte State, in the Brazilian northeast. With a sampling effort of 239 665 m2h, we captured 1575 individuals of 31 species of bats. Bat assemblages’ structure and species distribution changed according to the habitat type, and differences in richness, abundance, species composition, and trophic guild representation were found. The frugivore A. planirostris was widespread, and its superabundance hold for all habitats. The distinct array of the most abundant species with several exclusive species in each habitat suggests species- and trophic guild-specific preferences to particular habitats. Differences in the structure of bat assemblages may be driven by each habitat’s vegetational structure and plant composition (e.g., semi-open habitats vs. tall forest stands) that offers distinct exploitable resources (e.g., food and roosts). Finally, we discuss the importance of foraging habitats for the conservation of these unique bat assemblages in the northeasternmost region of the Caatinga dry forest.

Holothuria (Holothuria) dakarensis (Holothuroidea: Holothuriidae) is recorded for the first time in the south-western Atlantic, from mangroves in Macau, Rio Grande do Norte State, and deposited in the Coleção de Invertebrados Paulo Young, Universidade Federal da Paraíba, Brazil.

Six deep-sea fish species are recorded for the first time off north-eastern Brazil: Conger esculentus, Talismania homoptera, Physiculus kaupi, Ectreposebastes imus, Centrodraco oregonus and an unidentified species of Myroconger. The material was caught during the Programme REVIZEE (Programme for Assessment of the Sustainable Yield of Living Resources of the Exclusive Economic Zone) and by commercial fishery operations from 1998 to 2005 off the coasts of Ceará and Rio Grande do Norte States. These new records extend the geographical distribution range and fill geographical distribution gaps of the species herein reported.

A new species of Conidae is described from Brazilian waters. Mitromorpha santosi sp. nov. from the Continental Slope off the state of Rio Grande do Norte (north-east Brazil: 04°50′60″–04°51′40″s, 35°06′01″–35°06′46″W) is compared with M. biplicata (western Atlantic), M. usta (eastern Atlantic), M. dalli (north-eastern Atlantic), M. popeae (West Indies), M. undulate (West Indies) and two unnamed Brazilian species being diagnosed as possessing strong axial ribs, second spiral cord on the body whorl more pronounced and yellowish-brown spiral bands. In addition, a lectotype for Mitromorpha undulata, is designated herein.