Abstract
Two new cobitid species, Botia longidorsalis and B. caudipunctata, are described from the Lao Mekong basin. These species are fell into modesta-group of subgenus Hymenophysa in having short rostral and maxillary barbels, relatively large mental lobes, each with a pair of fleshy papillae at its anterior end, ordinary premaxillae not surrounding a cavity and a fontanelle on the top of the cranium. B. longidorsalis is the most similar to B. morleti, but is distinguishable from it and other species of modesta-group by the combination of the following characters: 9-10 branched dorsal fin rays, 30-31 total vertebrae, 13-18 narrow, irregular, brownish bars on the body sides, a broad, brownish bar on the caudal peduncle, and numerous small brownish spots on the caudal fin lobes. B. caudipunctata shows morphological similarities to B. lecontei and B. modesta, but differs from them and all other species by the combination of the following characters: 8 branched dorsal fin rays, 32-33 total vertebrae, brownish, saddle-shaped bands on the body behind the dorsal fin, a large, blurred blotch on the caudal peduncle, and pale dorsal, anal, pectoral and pelvic fins. The caudal fin has numerous small, brownish spots.
