New records, extended and updated geographic distribution of the South American native antlion Dimares elegans (Perty, 1833) (Neuroptera, Myrmeleontidae)

ABSTRACT An extensive review of primary and secondary occurrence data, including several new records, of the South American native antlion Dimares elegans (Perty) revealed that this species is endemic to regions of stressful water regime (Caatinga, Cerrado, Chaco and temperate fields) and adjacent areas in Amazon rainforest, Atlantic forest and Pampas. Its known distribution is from Santarém, Pará state, northern Brazil to Río Negro, Chimpay, northwestern Argentina. The known distribution of the species in Brazil has been extended, registering several areas above the São Francisco River (former possible northeastern limit). New limits further east were established from new primary records. For the first time the species is registered from the Brazillian states of Maranhão, Piauí, Rio Grande do Norte, Paraíba, Bahia, Goiáis, Tocantins, Minas Gerais, Mato Grosso do Sul, São Paulo and Paraná, Brazil. Historical data of occurrence in Goiás (Cerrado) have been geopolitically rectified (Tocantins) and, present occurrence in Goiás is reported by primary data in two new localities. Antlions are mostly xerofilous species, however with recent data this species might present much wider distribution than restricted to seasonally dry forests.

Macrobrachium/ Spence Bate, 1868 (Decapoda: Palaemonidae): New records, range extension and geographic distribution in the Northeastern Caatinga amp; Coastal Drainages, and São Francisco hydrographic ecoregions, Northeast of Brazil.

This study constitutes the most comprehensive effort ever done to assess the faunal diversity of the Macrobrachium genus within two ecoregions that encompass part of the northeastern Brazil: the Northeastern Caatinga Coastal Drainages, and the São Francisco (Lower-middle and Lower portions). Through sampling in several of their hydrographic basins, bibliographic research, and consulting scientific collections, our results reveal the occurrence of five species along these ecoregions: Macrobrachium acanthurus, M. amazonicum, M. carcinus, M. jelskii and M. olfersii. We also provide the first record of these species for several river basins in both ecoregions. Additionally, we confirm the occurrence of M. carcinus from Rio Grande do Norte State and provide updated distribution maps for each species in the studied area. This carcinofauna survey may form the basis for future evaluations of eventual anthropic impacts on biological diversity resulting from projects being implemented in these regions, which involve the São Francisco interbasin water transfer.

Gastropod shells used by Dardanus insignis (Decapoda, Anomura) near islands in the Ubatuba region, São Paulo, Brazil / Conchas de gastrópodos utilizadas por Dardanus insignis (Decapoda, Anomura) próximas de ilhas de região de Ubatuba, São Paulo, Brasil

The use of gastropod shells by hermit crabs is determined by the availability of shells in the environment or through selection for size and volume. This study analyzed patterns in the use of shells by Dardanus insignis (Saussure, 1858). From January 1998 to December 1999, 386 individuals were collected from two islands at Ubatuba, São Paulo. The crabs were measured for cephalothoracic shield length (CSL) and wet weight (CWW). The gastropod shells occupied by hermit crabs were identified, and the shell aperture width (SAW), dry weight (SDW) and internal volume (SIV) were measured. The relationships between the dimensions of the gastropod shell and the hermit crabs were evaluated by linear regression analysis. Among the 11 species of gastropod shells used by D. insignis, the most often used was Olivancillaria urceus (31%), followed by Strombus pugilis (22%) and Siratus tenuivaricosus (18%). The shell of O. urceus was used most probably due to its high availability on Couves and Mar Virado islands. The most significant biometric parameter was shell aperture width (F=18.231; p<0.0001), highlighting the importance of this variable for the shell choice by D. insignis at both sites.

O uso de conchas de gastrópodos por ermitões se dá de acordo com a disponibilidade no ambiente ou através de mecanismos seletivos relacionados, como o tamanho e volume. O objetivo deste trabalho foi analisar os padrões do uso de conchas por Dardanus insignis (Saussure, 1858). Durante o período de janeiro de 1998 a dezembro de 1999 foi coletado um total de 386 indivíduos em duas ilhas pertencentes à Ubatuba, São Paulo, os quais foram medidos de acordo com o comprimento do escudo cefalotoracico (CEC) e o peso úmido (PA). As conchas ocupadas pelos ermitões foram identificadas e mensuradas quanto a largura de abertura (LAC), peso (PSC) e volume interno da concha (VIC). As relações entre as variáveis da concha de gastrópodo e o ermitão, foram avaliadas através da análise de regressão linear. Dentre as onze espécies de concha de gastrópodes utilizadas por D. insignis, a mais usada foi Olivancillaria urceus (31%), seguida por Strombus pugilis (22%) e Siratus tenuivaricosus (18%). A concha de O. urceus foi a mais utilizada, provavelmente devido a sua maior disponibilidade na ilha das Couves e do Mar Virado. Os resultados mostraram que dos parâmetros biométricos mensurados das conchas, o mais significativo foi largura da abertura da concha (F=18.231; p<0.0001), evidenciando a importância desta variável para a escolha das conchas por D. insignis nos dois locais.