Two new species of Brotia from Laos (Mollusca, Caenogastropoda, Pachychilidae) Frank Kæhler * Museum fçr Naturkunde der Humboldt-Universitåt zu Berlin, Invalidenstraße 43, 10115 Berlin, Germany Introduction Freshwater snails of the genus Brotia H. Adams, 1866 typically inhabit mountain creeks and rivers in tropical forests of Southeast Asia. The distribution of these vi- viparous snails ranges from northeastern India to south- ern China in the northeast and Sumatra and Borneo in the southwest (Kæhler & Glaubrecht 2006). Recent stu- dies on the phylogenetic relationships of these gastro- pods (Kæhler et al. 2004) and a systematic revision of the genus itself (Kæhler & Glaubrecht 2006) have im- proved our knowledge of the group. From other pachy- chilid genera in Southeast Asia, such as Adamietta Brandt, 1974, Jagora Kæhler & Glaubrecht, 2003, Para- crostoma Cossmann, 1900, Sulcospira Troschel, 1858, and Tylomelania P. Sarasin & F. Sarasin, 1897, the genus Brotia has been distinguished by the diagnostic features of a wrinkled apical whorl of the embryonic or juvenile shell and a comparatively simple pallial ovi- duct possessing a deep spermatophore bursa and lack- ing a seminal receptacle (Kæhler & Glaubrecht 2006). This more restricted concept of Brotia as compared to more traditional approaches of e.g. Morrison (1954) and Brandt (1974) are supported also by a molecular phylogeny based on mt DNA data (Kæhler et al. 2004). Hence, together with the species newly described here- in, Brotia currently encompasses 37 species. However, thanks to the work of Brandt (1968, 1974) our current knowledge of pachychilid freshwater gastropods is still biased towards the well-studied fauna of Thailand whereas most regions in Southeast Asia remain inade- quately documented. Particularly the distributional lim- its of Brotia towards the east and north (i.e., in Laos, Southern China, and Vietnam) are uncertain; data from these regions are scarce. The few historical accounts available on Laotian freshwater gastropods were mostly based on dry shell material. Because in the Pachychili- dae knowledge of the soft body and particularly the embryonic shell morphology is crucial for a correct generic affiliation (Kæhler & Glaubrecht 2001, 2005), the unavailability of these data frequently hinders a re- liable decision on the current status of species known only from shells being kept in museum collections. As a consequence, among the various museum collections examined by the author (Kæhler & Glaubrecht 2006), there are only few records of pachychilid species from Laos in the Musum National d’Histoire Naturelle Paris (MNHN), the Nationaal Naturhistorisch Museum Lei- den (RMNH) and the Zoologisches Institut und Mu- seum Hamburg (ZMH) that can be attributed to Brotia with certainty. Hence, in addition to B. dautzenbergiana (Morlet, 1884) and B. jullieni (Deshayes, 1874), the Zoosyst. Evol. 84 (1) 2008, 49 – 55 / DOI 10.1002/mmnz.200700013 museum fu ¨ r naturkunde der Humboldt-Universita ¨ t zu Berlin # 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Received 22 May 2007 Accepted 9 August 2007 Published 17 March 2008 Key Words Gastropoda Cerithioidea freshwater gastropods Southeast Asia Abstract Two new species of pachychilid freshwater gastropods, Brotia laodelectata and Brotia mariae, are described based on the examination of preserved specimens recently col- lected in rivers of Central Laos. This new report adds to the scant knowledge of the freshwater gastropod fauna of this country. Currently, four species of Brotia are known from Laos of which the newly described species are thought to be unique to the coun- try. However, available data on the occurrence of pachychilid gastropods in Laos obtained from museum records and by personal observations in the field in 2006 are restricted essentially to some areas in Central and Southern Laos. The freshwater gas- tropod fauna of northern Laos remains largely unknown. * E-mail: frank.koehler@museum.hu-berlin.de