Comparative Morphology and Morphometry of the Olfactory Organ in the Five Korean Torrent Catfishes, Genus , with a Taxonomic View.

The morphology and morphometry of the olfactory organ of Korean torrent catfishes, genus , consisting of only five endemic species, were investigated by stereo microscopy, scanning electron microscopy, and statistical analysis. They showed the same morphological structure, externally and internally, including a tubular anterior nostril, a slit posterior nostril, and a rosette structure with several linguiform lamellae. Interestingly, however, the lamellar number (LN) revealed specific characteristics useful to identify the five species anatomically: 16-19 in (with standard length, SL, 96.8 ± 5.5 mm, mean ± SD), 14-16 in (86.9 ± 13.4 mm), 22-27 in (99.8 14.7 mm), 19-24 in (90.1 ± 6.7 mm), and 14-18 in (74.0 ± 6.7 mm). Regarding SL, that of . was longer than those of . and . . As opposed to the SL, the LN to SL ratios of . (24.1 ± 2.1%) and . (21.1 ± 1.4%) were greater than that of . (18 ± 1.2%). These differences might be considered to reflect an interspecific morphological adaptation to micro-habitat according to olfactory importance and can be used as a taxonomic characteristic for this genus.