CORRELATIONS AMONG MOFPHOMETRIC TRAITS OF FINGERLING CATFISHES AND THE RELATIONSHIP TO DRESSING PERCENTAGE AT HARVEST

Abstract

ABSTRACT Blue ( Ictalurus furcatus ), channel ( I. punctatus ), white ( I. catus ) and hybrid catfish grown under similar conditions to a size of 30 g differed in their body conformation (head length, head width, head depth, body depth, caudal peduncle depth and caudal peduncle width to total length ratios; P <.01) and dressing percentage (P < .05). Strains of channel catfish also differed from each other in their body conformation (P < .01) and dressing percentage (P < .05). Body conformation at 30 g was correlated to dressing percentage at 500 g (P < .01). Head width, caudal width and body depth had the largest effects upon dressing percentage (P < .05). Blue catfish, Auburn and Rio Grande strains of channel catfish had higher dressing percentage (P < .05) than the hybrids, white catfish and four remaining channel catfish crosses. Auburn x Rio Grande channel catfish crossbreds had larger (P < .01) heads, caudal peduncles and body depth than their parents, but the Marion x Kansas crossbred channel catfish did not have larger values than their parents. It appears that overdominance for body conformation was prevalent in intraspecific crossbreds. Morphologies of channel‐blue hybrids were between those of their parent species. The correlations between morphometric traits were different (P < .01) among the 10 genetic groups.