Balakirev A.E., Abramov A.V., Rozhnov V.V. 2012. Taxonomic revision of Niviventer (Rodentia, Muridae) from Vietnam: a morphological and molecular approach // Russian J. Theriol. Vol.10 (for 2011). No.1: 1–26 [in English].
Alexander E. Balakirev [firstname.lastname@example.org] and Viatcheslav V. Rozhnov [email@example.com], A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninskii pr. 33, Moscow 119071, Russia; Joint Vietnam-Russian Tropical Research and Technological Centre,
Nguyen Van Huyen, Nghia Do, Cau Giay, Hanoi, Vietnam;
Alexei V. Abramov [firstname.lastname@example.org], Zoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, Saint Petersburg 199034, Russia; Joint Vietnam-Russian Tropical Research and Technological Centre, Nguyen Van Huyen, Nghia Do, Cau Giay, Hanoi, Vietnam.
KEY WORDS: Niviventer, Muridae, Indochina, Vietnam, molecular phylogeny, taxonomy, morphological identification.
ABSTRACT. Based on a comparative investigation of morphological and genetic data, a taxonomic revision of the genus Niviventer in Vietnam and the adjacent regions of East Indochina was carried out. The phylogenetic relationships within 13 species (N. andersoni, N. excelsior, N. eha, N. brahma, N. culturatus, N. coninga, N. rapit, N. niviventer, N. confucianus, N. tenaster, N. fulvescens, N. langbianis and N. cremoriventer) were investigated based on a full set of cytochrome b sequences and the cytochrome coxidase subunit I genes that are currently available. The full species rank for N. huang and N. bukit, which previously were regarded as forms of N. fulvescens, was approved. The occurrence of the members of the Malayan complex of species (N. tenaster, N. bukit and N. cremoriventer) among the mammal fauna of Southern Vietnam was established. The geographical distribution of the genetic lineages/species in Indochina is specified. It was shown that eight Niviventer species, namely N. niviventer, N. confucianus, N. bukit, N. tenaster, N. fulvescens, N. huang, N. langbianis and N. cremoriventer, occur in Vietnam. Some species (N. bukit, N. huang and N. langbianis) were demonstrated to be sympatrically distributed, whereas the others (N. fulvescens – N. huang and, apparently, N. cremoriventer – N. langbianis) formed vicariate pairs. Four species (N. niviventer, N. confucianus, N. fulvescens, and N. langbianis), were found to inhabit Northern Vietnam and the adjacent provinces of China (Yunnan, Guizhou); four species (N. tenaster, N. bukit, N. huang and N. langbianis) were recorded in the mountain regions of Central Vietnam and Laos; and three others (N. bukit, N. cremoriventer and N. huang) were found to inhabit most of the plains in Indochina, including Southern Vietnam, Cambodia, and a part of Thailand. It should be stressed that N. huang (but not N. fulvescens as it is usually considered) is the most common Niviventer species in Indochina, and its distribution range stretches over the plains of Thailand, Cambodia and Vietnam up to the south-eastern provinces of China.
Craniometrical characters and indexes were studied by applying discriminant analysis; the species-specific pattern of skull proportions and its applicability for species identification were demonstrated for some of the characters and indexes. By morphological analysis of genetically verified specimens, morphologically detailed descriptions of the external appearance and structural traits of the skull were presented for all eight Vietnamese Niviventer species. Practical recommendations and guidelines for visual species identification are also given. The size of the body and skull, the comparative length and the specific pattern of coloration of the tail and tail tip as well as the dorsal side of the feet, the size and shape of the auditory bullae, the comparative length of the incisive foramina and the bony palatal bridge and the extent of development of supraorbital ridges were demonstrated to be the most informative features for species identification.