Accepted by S. Ahyong: 27 Mar. 2009; published: 1 May 2009 31 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2009 · Magnolia Press Zootaxa 2088: 31–40 (2009) www.mapress.com/ zootaxa/ Article Aegla manuinflata, a new species of freshwater anomuran (Decapoda: Anomura: Aeglidae) from Brazil, determined by morphological and molecular characters SANDRO SANTOS 1,4 , GEORGINA BOND-BUCKUP 2 , MARCOS PÉREZ-LOSADA 3 , MARLISE LADVOCAT BARTHOLOMEI-SANTOS 1 & LUDWIG BUCKUP 2 1 Departamento de Biologia, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brazil. E-mail: ssantos@smail.ufsm.br; marlise@smail.ufsm.br 2 Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, 91510-970 Porto Alegre, Rio Grande do Sul, Brazil. E- mail: ginabb@yahoo.com.br; lbuckup@yahoo.com.br 3 CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, 4485- 661 Vairão, Portugal. E-mail: mlosada323@genoma-llc.com 4 Corresponding author Abstract A new species of freshwater anomuran, Aegla manuinflata n. sp. (Decapoda: Anomura: Aeglidae), is described from the Ibicuí River basin, a tributary of the Uruguay River, from the central region of the state of Rio Grande do Sul, Brazil. It can be distinguished from its congeners based on both morphological and molecular (mitochondrial gene — COII) evidence. Morphologically, the new species partly resembles A. inermis and A. uruguayana, but differs in having an inflated cheliped propodus and more elongated dactyls, besides other features. Our molecular results showed a high degree of genetic divergence between A. manuinflata and its sister group (composed of A. singularis, A. uruguayana, A. rossiana and A. platensis), an indication of species distinctness within the Aeglidae. Key words: Aeglidae, Anomuran crab, biogeography, COII, mtDNA sequence, Uruguay basin Introduction Fossil records of Protaegla miniscula Feldmann et al., 1998 (~150 Mya) and Haumuriaegla glaessneri Feldmann, 1984 (~75 Mya) support the marine origin of the family Aeglidae, the only anomuran group now living exclusively in continental waters. Based on the geological history of South America, the formation of its hydrographic basins, and the phylogenetic analysis of Aeglidae, Pérez-Losada et al. (2004) estimated the age of the root of the Aeglidae tree as 74 Mya. According to these authors, this suggests that the colonization of southern South America and hence the origin of freshwater Aeglidae is post-Andean and occurred during the Late Cretaceous marine transgression (~70 Mya). From that time to the present, the drainage basins of South America have undergone considerable shifts (Potter 1997). According to the records, the last great transformation was the final uplift of the Coastal Range (Serra do Mar) in southern Brazil. This uplift altered the upper courses of east-flowing tributaries of rivers in paleo-Paraná and paleo-Uruguay, so that some short montane rivers were diverted eastward. This configuration is particularly remarkable in the state of Rio Grande do Sul in southern Brazil, where the drainages were split into two hydrographic basins, the Uruguay and the Southeast. The former basin is located to the west, formed by the Pelotas, Erechim and Turvo rivers in the northern region of the state and the Ijuí, Ibicuí and Quaraí in the western region, all of them draining into the Uruguay River. The latter basin is formed by the Jacuí, Sinos, Caí and Camaquã rivers, all of them draining into the Patos Lagoon, which has its mouth at the city of Rio Grande (Fig. 1). TERMS OF USE This pdf is provided by Magnolia Press for private/research use. Commercial sale or deposition in a public library or website is prohibited.