DESCRIPTION OF THE TADPOLES OF Leptobrachium chapaense (BOURRET, 1937) IN PU LUONG NATURE RESERVE, THANH HOA PROVINCE

This study provides morphological data on the tadpoles of Leptobrachium chapaense (Bourret, 1937), based on specimens collected from the Pu Luong Nature Reserve (NR), Thanh Hoa Province, Vietnam. The tadpoles exhibit several typical diagnostic features of the species, including relatively large body size; cylindrical body slightly wider than tall; small eyes; thick and robust tail musculature with a blunt tail tip; and a single spiracle located on the left side, slightly closer to the vent than to the snout tip. The oral disc is oriented anteroventrally and is surrounded by a single row of marginal papillae, with a medial gap on the upper lip. The jaw sheaths are entirely black; the upper sheath has a serrated lower edge, while the lower sheath is thick and shallowly concave. The labial tooth row formula (LTRF) is I(6+6)/(5+5)-(7+7)I. Compared to tadpoles from Bach Ma National Park (NP), the Pu Luong specimens exhibit a greater interorbital/internasal ratio and body length/body width ratio. The upper labial tooth rows in Pu Luong specimens are more consistent (6+6), while Bach Ma specimens show a broader range from (6+6) to (8+8). In terms of morphological correlations, body length is closely associated with hind limb development, tail base formation, and spiracle emergence and regression. Body width and body height also exhibit a strong positive correlation. Keywords: Tadpole metamorphosis; Leptobrachium chapaense; Pu Luong Nature Reserve