This study identified the differences in the morphometric characteristics of the truss and classical dimensions between diploid and triploid Far Eastern catfish, Silurus asotus, and provided methods for sorting diploid and triploid Far Eastern catfish based on morphometric observations. The significant variables were the direct distance between the anterior edge of the lower lip and the anterior insertion of the dorsal fin (DALAD), the horizontal distance between the anterior edge of the lower lip and the anterior insertion of the ventral fin (HALAV), the direct distance between the anterior edge of the upper lip and the first nostril (DAUF), the direct distance between the anterior edge of the upper lip and the second nostril (DAUS), the interorbital width (IW), and the mandible barbel length (ManBL). The more significant variables were HALAV, DALAD, DAUF, IW, and DAUS. The most useful combination of variables for separating the two groups was DALAD, IW, and DAUF, which correctly classified 85% of the catfish as triploid or diploid, and that percentage was the maximum degree of value possible (p<0.05). Triploid Far Eastern catfish had a high rate of growth in the head region and body depth during the first year after hatching. Triploid Far Eastern catfish had smaller heads and shorter mandible barbels than diploid Far Eastern catfish.

We used flowcytometry to ploidy verification after that investigate difference between diploid and spontaneous triploid through the truss dimension and classical dimension at crucian carp, Carassius auratus, crucian carp C. cuvieri and common carp, Cyprinus carpio collected from Hangang river, Hantangang river, Imjingang river, Geumgang river, Yeongsangang river and Nakdonggang river, Korea. There were significant differences among the three species for the truss dimensions anterior origin of dorsal fin (2)× anterior origin of anal fin (5), 2× anterior origin of pelvic fin (6), 2× origin of pectoral fin (7), posterior origin of dorsal fin (3)×5, 3×6, and 3×7 (P<0.05). There were no significant differences among the three species in the truss dimensions dorsal fin length (2×9) and eye diameter (ED)(P>0.05). On the other hand, there were no significant differences in the several classical dimensions of each species (P>0.05). Three classical dimensions, most anterior extension of the head (1)×2, 1×6 and 2× most posterior scale in lateral line (4) did not differ between the C. auratus diploid and spontaneous triploid (P>0.05). Two classical dimensions, 1×6 and longest length between most anterior extension of the head and gill cover (1×8) did not differ between the C. cuvieri diploid and spontaneous triploid (P>0.05). One classical dimensions, 1×2 did not differ between the common carp diploid and spontaneous triploid (P>0.05). There were significant differences in the each diploid and triploid species (P<0.05). These results suggest that the classification of each species and classification between diploid and spontaneous triploid morphometrical parameters used in this study are useful indices of morphometrical status in the each species from major river of Korea.

The present study determined the differences in the morphometric characteristics of truss and classical dimensions between diploid and triploid Far Eastern catfish, Silurus asotus and provided methods for separating diploid and triploid Far Eastern catfish based on morphometric observations. Significant variables were the direct distance between the anterior edge of the lower lip and the anterior insertion of the dorsal fin (DALAD), the horizontal distance between the anterior edge of the lower lip and the anterior insertion of the ventral fin (HALAV), the direct distance between the anterior edge of the upper lip and the first nostril (DAUF), the direct distance between the anterior edge of the upper lip and the second nostril (DAUS), the interorbital width (IW), and the mandible barbel length (ManBL). The more significant variables were DALAD, HALAV, DAUF, DAUS, and IW. The most useful combination of variables for separating the two groups was DALAD, IW, and DAUF, which correctly classified 85% of the catfish as triploid or diploid, the maximum degree of separation obtained (P<0.05). The triploid catfish had high head region and body depth growth rates during the first year after hatching. Triploid catfish had smaller heads and shorter mandible barbels than diploid catfish.