Phylogeography and genetic ancestry of tigers (Panthera tigris).

Eight traditional subspecies of tiger (Panthera tigris),of which three recently became extinct, are commonly recognized on the basis of geographic isolation and morphological characteristics. To investigate the species' evolutionary history and to establish objective methods for subspecies recognition, voucher specimens of blood, skin, hair, and/or skin biopsies from 134 tigers with verified geographic origins or heritage across the whole distribution range were examined for three molecular markers: (1) 4.0 kb of mitochondrial DNA (mtDNA) sequence; (2) allele variation in the nuclear major histocompatibility complex class II DRB gene; and (3) composite nuclear microsatellite genotypes based on 30 loci.

Ampullary organs, pit organs, and neuromasts of the chinese giant salamander, Andrias davidianus.

The lateral-line sense organs in the skin of larval, juvenile and adult salamanders (Andrias davidianus) were examined by light and scanning electron microscopy. In addition to mechanoreceptive neuromasts, there are electroreceptive ampullary organs. Anatomically, the latter are similar to the ampullary organs of some other urodeles.