Caudal fin abnormality and growth and survival of channel catfish

From 109 egg masses of channel catfish (Ictalurus punctatus) artificially incubated in the summer of 1981, the fry hatched from 6 egg masses showed some forms of tail abnormality. The morphological deviations from normal fish were classified as tailless, partially-tailed, and triple-tailed (three-lobed). Relative frequencies of these phenotypes varied within and among full-sib families. Absence or partial absence of caudal fin was associated with spine structure abnormalities and severe growth depression. Triple-tailed fish were comparable in tank growth to normally-tailed fish but were superior in cage growth. An association between low hatchability scores and caudal fin abnormality was observed which should be taken into consideration in any breeding program. Differences in body pigmentation was associated with differences in growth of tailless and partially-tailed catfish. Normally pigmented tailless were comparable in body weight to partially-tailed fish. Tailless albinos were, however, inferior in body weight and total length to partially-tailed albinos. Normally pigmented fish were consistently superior to abnormally-tailed fish, regardless of skin pigmentation.