-Batrachuperus mustersi occurs only in the Paghman Mountains of Afghanistan in a single stream. They inhabit the cold sources of the stream where they are active year-round, feeding on aquatic organisms. Morphological examination revealed many similarities to other members of the genus. Differences were found in the tail morphology, degree of skeletal ossification and gill development. The only adult sexual dimorphism is in the appearance of the cloaca. Redescriptions of the morphology of adults and larvae are given. Niche partitioning was found in habitat selection and prey size. Breeding coincides with the spring thaw when females lay at least two egg cases and attach them to submerged rocks or plants. Metamorphosis also takes place in the spring after two years of development. The genus Batrachuperus was described by Boulenger in 1878, at which time only one species, Batrachuperus pinchoni, was known. Presently eight species are recognized, occurring in two geographic divisions. Five species are found in relative close proximity in the mountainous regions of Szechwan and far eastern Tibet. B. pinchoni, B. karlschmidti and B. cochranae may be found together in streams in Szechwan province and B. yenyuanensis inhabits pools at higher altitudes (Thorn, 1968). B. tibetanus occurs to the north on the Tibetan border of Kansu. Liu (1950) gives detailed accounts of the Batrachuperus species of western China. Three more recently described species are found far to the west in Iran and Afghanistan. B. persicus and B. gorganensis occur on the north slopes of the Elburz Mountains (ClergueGazeau and Thorn, 1978) and B. mustersi lives in the Paghman Mountains on the southern slopes of the Hindu Kush in Afghanistan. Research on this species has been limited to a short natural history paper by Nawabi (1965), which briefly discusses the habitat and egg cases. This I Present address: Department of Zoology, Southern Illinois University, Carbondale, Illinois 62901, USA. paper is the first extensive description of B. mustersi, its range and ecology. MATERIALS AND METHODS Field work consisted of 20 trips to the Paghman Mountains 23 km northwest of Kabul, Afghanistan. Periodic samples were taken between 9 June 1977 and 9 March 1978. During that time the entire range of Batrachuperus mustersi was ascertained. Observations were made in the field, in the laboratory in Kabul, and later on specimens maintained in the laboratory at San Francisco State University for breeding experiments. Preserved specimens are deposited at the California Academy of Sciences (CAS 146985-147108; 152088). Morphological measurements were made on 106 preserved specimens. The left gonad was removed from sexually mature adults and volume, oocyte number and diameter were measured where appropriate. The specimens were grouped males, females and larvae and dispersion statistics (mean, range, variance, and standard error) were calculated for each group to allow comparisons between the groups and to look for evidence of sexual dimorphism. Stomach and intestinal contents were removed and identifiable food items recorded for each specimen. Food items for all specimens were then grouped by This content downloaded from 207.46.13.115 on Sat, 08 Oct 2016 05:27:08 UTC All use subject to http://about.jstor.org/terms