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C. B. COWEY AND J. R. SAROENT
of protein, the essential amino acid requirements of chinook salmon
(Oncorhynchus tshawytscha (Walb.)) were established (Halver et al.,
1957). Amino acid deficient diets were formed by eliminating one amino
acid at a time from the basic diet and replacing it with an equal weight
of a-cellulose flour. Growth on the amino acid deficient diets was
compared with that on the basal ration. It was shown that arginine,
histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine were necessary for normal growth. Similar
methods were applied to sockeye salmon 0. nerka (Walb.) (Halver
and Shanks, 1960) and to rainbow trout Salmo gairdneri Richardson
(Shanks et al., 1962). The results obtained were identical.
Later similar methods were applied to the establishment of
essential amino acids of channel catfish, Ictalurus punctatus (Rafinesque)
(Dupree and Halver, 1970). However, Halver’s original test diet
would not support growth in channel catfish fingerlings. Only when a
low magnesium, low sulphate salt mixture was used to replace the
original salt mixture would the complete dietary mixture support
growth. The need for this dietary modification and the reason for its
success is obscure. Possibly retention time in the intestine was too
short on the original diet or perhaps the assimilatory mechanism
requires a particular ionic balance. Again the essential amino acid
requirements for channel catfish were identical with other fish studied.
A similar pattern is emerging from studies on eel, Anguilla japonica
(Temminck and Schlegel) (Nose, 1969).
Aoe et al. (1970) have used Halver’s test diet with young carp,
Cyprinus carpio L. However, they were unable to obtain growth on
amino acid test diets despite the employment of various combinations
of binder and the modified salt mixture of Dupree and Halver. Growth
was obtained with test diets which contained protein (casein). Over
90% of the nitrogen in the amino acid test diet was absorbed although
the retention time in the intestine was only half that on a casein diet.
Aoe et al. feel that the failure of carp to grow on amino acid test diets
could not be attributed to the composition of the amino acid mixture
used-rainbow trout fed on the same diets at the same time grew
normally. Some facet of gastrointestinal physiology may be markedly
different in the carp.
An indirect approach was used to identify the essential amino acids
for plaice and sole (Solea solea) (Cowey et al., 1970b). Fish were given
intraperitoneal injections of p-14C] glucose and, after radioactivity in
the expired carbon dioxide had been monitored for six days, the fish
were killed, the tissue protein isolated, hydrolyzed and the constituent
amino acids resolved and purified. They were then examined for
C. B. COWEY AND J. R. SAROENT
of protein, the essential amino acid requirements of chinook salmon
(Oncorhynchus tshawytscha (Walb.)) were established (Halver et al.,
1957). Amino acid deficient diets were formed by eliminating one amino
acid at a time from the basic diet and replacing it with an equal weight
of a-cellulose flour. Growth on the amino acid deficient diets was
compared with that on the basal ration. It was shown that arginine,
histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine were necessary for normal growth. Similar
methods were applied to sockeye salmon 0. nerka (Walb.) (Halver
and Shanks, 1960) and to rainbow trout Salmo gairdneri Richardson
(Shanks et al., 1962). The results obtained were identical.
Later similar methods were applied to the establishment of
essential amino acids of channel catfish, Ictalurus punctatus (Rafinesque)
(Dupree and Halver, 1970). However, Halver’s original test diet
would not support growth in channel catfish fingerlings. Only when a
low magnesium, low sulphate salt mixture was used to replace the
original salt mixture would the complete dietary mixture support
growth. The need for this dietary modification and the reason for its
success is obscure. Possibly retention time in the intestine was too
short on the original diet or perhaps the assimilatory mechanism
requires a particular ionic balance. Again the essential amino acid
requirements for channel catfish were identical with other fish studied.
A similar pattern is emerging from studies on eel, Anguilla japonica
(Temminck and Schlegel) (Nose, 1969).
Aoe et al. (1970) have used Halver’s test diet with young carp,
Cyprinus carpio L. However, they were unable to obtain growth on
amino acid test diets despite the employment of various combinations
of binder and the modified salt mixture of Dupree and Halver. Growth
was obtained with test diets which contained protein (casein). Over
90% of the nitrogen in the amino acid test diet was absorbed although
the retention time in the intestine was only half that on a casein diet.
Aoe et al. feel that the failure of carp to grow on amino acid test diets
could not be attributed to the composition of the amino acid mixture
used-rainbow trout fed on the same diets at the same time grew
normally. Some facet of gastrointestinal physiology may be markedly
different in the carp.
An indirect approach was used to identify the essential amino acids
for plaice and sole (Solea solea) (Cowey et al., 1970b). Fish were given
intraperitoneal injections of p-14C] glucose and, after radioactivity in
the expired carbon dioxide had been monitored for six days, the fish
were killed, the tissue protein isolated, hydrolyzed and the constituent
amino acids resolved and purified. They were then examined for