56
K. Dabrowski et a1.
INTRODUCTI_QË
Formulated diets designed specifically for cyprinid fish are still in
its infancy, but their improvement is the only way to grow fish more rapidly
and healthier in intensive facilities. The recent reviews dealing with nutri—
ent
requirements include those specifically devoted to carp (Dabrowski, 1979,
1981; Jauncey, 1982) and to fish in general, with wide attention to carp
Ÿ
(Millikin, 1982). We attempt to give the basic knowledge of carp nutrition
and summarize the newest data, but former reviews should be consulted for
detailed information and referenees.
;
I.
NUTRITIONAL PHYSIOLOGY
Amine acids have been shown to be important chemical signals eliciting
Ï
feeding response through the olfactory and gustatory system in many fish spe—
;
cies.
Stimulation of chemoreceptors by specific amino acid receptors response
might have also practical approach in increasing attractiveness of food pre—
sented to fish.
In carp the taste system.was claimed to be more sensitive to
amino acids than the olfactory system (Marui et al., 1983), but
Ohno
et
al.
(1984) found in carp olfactory bulbar response threshold
of
10“ M
for serine.
For
gustatory system the threshold for proline was 10—8°5M. The
external
taste
system of carp responded to neutral and acidic amino acid, but
f
not
to basic ones, and response was stereospecific (Marui et al., 1983).
The relative lenghh of intestine increases during the larval and juvenile period of cyprinid fish and in some species can reach 6—24 tinæs body
length (Stroband and Dabrowski, 1981). However, the consequence of the
tive intestinal length is not clear in food utilization comparison between
several cyprinid species. Common carp fingerlings
utilized better, both fish
meal and Silk worm pupae based diets, than long—intestine Labeo rohita
î
(Jayaram and Shetty, 1980a). Growth response to various protein sources in
3
diets offered to Catla catla, Laboe rohita and common carp varied during the
trial, but Jayaram and Shetty (1980b) did not discuss these results in the
”
light of digestive tract morphology of studied fish.
It is believed that proteolytic enzymes activity is higher in
than in herbivorous fish species although this "ecological" division might
have less
importance in feeding on formulated diets. There is evidence of
endogenous control of digestive enzymes activity in cyprinid fish, in both
proteases and amylases (Hofer, 1979a, b). Surprisingly little attention was
payed to this problem since it can have fargoing cnnsequences in eurythermal
;
cyprinids as is the case in different level of biochemical adaptations, i.e.
i
contractile proteins (Penney and Goldspink, 1981) or protein synthesis (Krauskopf et al., 1981). Although same pepsin—like activity was indicated in CY“
Ï
prinid fish (Hsu and Wu, 1979) it seems to be of intracellular origin. The
?
latter authors
found high positive correlation between trypsin and chymotïy8'
Sin
activity and relative lenght of intestine among 8 fish species. Hofer and
Sch1emer
(1981) suggested that relative intestine length correlates with amo“
unt
of proteolytic enzymes "reabsorbed" in the posterior intestine known to
have p1nocytotic activity of enterocytes. Even assuming that autodigestion
and inactivation of enzymes are negligible in cyprinid fish intestine (Hofer
Ï
1982)
the analysis of enzymes firmly bound to digesta particles cause analy*
tical problems.
The attractive hypothesis of the enteropancreatic circulation in fish awaits eXperimental study.
theircîïî ÎÏYPSlD, chymotrypsin
and elastase
have optimum pH at 8.2—8.8. and
a
yt1c
act1v1t1es
towards amide bonds of substrates was two orders
.
of mignitude higher than mammalian enzymes (Cohen et al. 1981).
K. Dabrowski et a1.
INTRODUCTI_QË
Formulated diets designed specifically for cyprinid fish are still in
its infancy, but their improvement is the only way to grow fish more rapidly
and healthier in intensive facilities. The recent reviews dealing with nutri—
ent
requirements include those specifically devoted to carp (Dabrowski, 1979,
1981; Jauncey, 1982) and to fish in general, with wide attention to carp
Ÿ
(Millikin, 1982). We attempt to give the basic knowledge of carp nutrition
and summarize the newest data, but former reviews should be consulted for
detailed information and referenees.
;
I.
NUTRITIONAL PHYSIOLOGY
Amine acids have been shown to be important chemical signals eliciting
Ï
feeding response through the olfactory and gustatory system in many fish spe—
;
cies.
Stimulation of chemoreceptors by specific amino acid receptors response
might have also practical approach in increasing attractiveness of food pre—
sented to fish.
In carp the taste system.was claimed to be more sensitive to
amino acids than the olfactory system (Marui et al., 1983), but
Ohno
et
al.
(1984) found in carp olfactory bulbar response threshold
of
10“ M
for serine.
For
gustatory system the threshold for proline was 10—8°5M. The
external
taste
system of carp responded to neutral and acidic amino acid, but
f
not
to basic ones, and response was stereospecific (Marui et al., 1983).
The relative lenghh of intestine increases during the larval and juvenile period of cyprinid fish and in some species can reach 6—24 tinæs body
length (Stroband and Dabrowski, 1981). However, the consequence of the
tive intestinal length is not clear in food utilization comparison between
several cyprinid species. Common carp fingerlings
utilized better, both fish
meal and Silk worm pupae based diets, than long—intestine Labeo rohita
î
(Jayaram and Shetty, 1980a). Growth response to various protein sources in
3
diets offered to Catla catla, Laboe rohita and common carp varied during the
trial, but Jayaram and Shetty (1980b) did not discuss these results in the
”
light of digestive tract morphology of studied fish.
It is believed that proteolytic enzymes activity is higher in
than in herbivorous fish species although this "ecological" division might
have less
importance in feeding on formulated diets. There is evidence of
endogenous control of digestive enzymes activity in cyprinid fish, in both
proteases and amylases (Hofer, 1979a, b). Surprisingly little attention was
payed to this problem since it can have fargoing cnnsequences in eurythermal
;
cyprinids as is the case in different level of biochemical adaptations, i.e.
i
contractile proteins (Penney and Goldspink, 1981) or protein synthesis (Krauskopf et al., 1981). Although same pepsin—like activity was indicated in CY“
Ï
prinid fish (Hsu and Wu, 1979) it seems to be of intracellular origin. The
?
latter authors
found high positive correlation between trypsin and chymotïy8'
Sin
activity and relative lenght of intestine among 8 fish species. Hofer and
Sch1emer
(1981) suggested that relative intestine length correlates with amo“
unt
of proteolytic enzymes "reabsorbed" in the posterior intestine known to
have p1nocytotic activity of enterocytes. Even assuming that autodigestion
and inactivation of enzymes are negligible in cyprinid fish intestine (Hofer
Ï
1982)
the analysis of enzymes firmly bound to digesta particles cause analy*
tical problems.
The attractive hypothesis of the enteropancreatic circulation in fish awaits eXperimental study.
theircîïî ÎÏYPSlD, chymotrypsin
and elastase
have optimum pH at 8.2—8.8. and
a
yt1c
act1v1t1es
towards amide bonds of substrates was two orders
.
of mignitude higher than mammalian enzymes (Cohen et al. 1981).