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Ontogenetic Sensitivity of Channel Catfish to Ascorbic Acid Deficiency
Author(s) -
Dabrowski Konrad,
Moreau Regis,
ElSaidy Deyab,
Ebeling James
Publication year - 1996
Publication title -
journal of aquatic animal health
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 52
eISSN - 1548-8667
pISSN - 0899-7659
DOI - 10.1577/1548-8667(1996)008<0022:osocct>2.3.co;2
Subject(s) - catfish , biology , ascorbic acid , ictalurus , zoology , vitamin , ascorbic acid deficiency , vitamin c , ontogeny , starter , endocrinology , medicine , fish <actinopterygii> , food science , fishery
Two distinct nutritional experiments were conducted sequentially with fry of channel catfish Ictalurus punctatus . Initial weight of fish was 0.030 ± 0.003 g in experiment 1 and 1.36 ± 0.03 g in experiment 2. In both experiments, fry were fed a semipurified, casein–gelatin‐based diet containing no ascorbate supplement (AA‐free) or a diet supplemented with 640 mg ascorbate/ kg as ascorbyl monophosphate (AP); fry used in experiment 2 had been given the AP‐supplemented diet in experiment L Fish fed a diet devoid of vitamin C showed significantly reduced growth after 14 d in experiment 1 and 28 d in experiment 2. In experiment 1, fry fed starter feed lacking vitamin C showed significantly increased mortalities during the sixth through eighth weeks. At the same time, gross clinical signs of deficiency appeared, such as darker skin pigment, scoliosis, lordosis, and eroded fins. In experiment 2, larger fry did not show any mortality or external pathologies during the 54 d of the feeding study. The ascorbate concentration in whole fish bodies before exogeneous feeding was 19.6 ± 0.7 μg/g and did not change after 8 weeks when fish increased their body weight 48‐fold on an AP‐supplemented diet (experiment 1). Small fry fed an AA‐free diet increased their body weight 9‐fold, and ascorbate was below detectable levels (0.5 μg/g). Larger fry fed an ascorbate‐supplemented diet had significantly higher concentrations of ascorbate in the liver (8.3 ± 0.3 μg/g) and kidneys (13.2 ± 0.9 μg/g) than fish fed a diet devoid of this vitamin.