Larva! nufrional&pysiolgy
223
Formulation of Practical 9£ Purified Diets.,
For
nutritional
studies
to
be
successful,ï
the
formulation of
a
purified
or
semi—purified
artificial
diet
is
essential;
In
the
case
of
Salmonids,
use
of
crystalline
amino—acid
based diets
have
proved successful
(Halver 1957),
whereas
in
the
Carp,
such
amino acid based diets
have
not
been
so°
A
number
of
comparisons between a whole protein diet
and
an
amino
acid diet have been undertaken.
In
the
adult
Carp,
differences
in
the
absorption of
amino
acids
were
reported
(Plakas et al°
1980).:
In
juvenile Carp, a comparison
between
-casein—bäEed—diet and an amino acid mixture diet
of
similar
composition showed that despite equivalent
intakes,
digestibility
and
transit
rates,
negative nitrogen
balance
was
noted
in Carp fed the latter diet
(Kaushik and Dabrowski
l983b),
Ammonia excretion was
low in those
fed
amino
acids,
suggesting
that
like
in
the
case
of
the
adult
Carp
(Murai et
al°
1984),
free
amino acids might be excreted by young CaËE
fËd such diets,
The
currently
successful
artificial
diets
for
Carp
larval
rearing have in their composition, variable amounts of single
cell
proteins and the effects of the contribution of
nucleic
acids
during
early growth is not yet well
understood.
Few
hypotheses
.on
specific
nutritional
needs,
especially
of
stomachless fish larvae have been put forward (Dabrowski
and
Kaushik
1982)
'and they require validation.
Lam
and
Sharma
(1985)
suggested
addition thyroxine
to
the
culture
milieu enhanced survival
and
growth of Carp.
Our
own
trials
with
dietary incorporation of thyroxine showed no beneficial
effects
and
Dabrowski,
unpublished).
the
currently
available
rearing
facilities
and
(CharlOn
and
Bergot 1984),
we
can
hope to obtain more basic
data
on
the nutritional needs of fish larvae
in
the
near
future.
REFERENCES
Bergot
P.,
Durante
H.,
1986.
The
effect
of
compound
dietS'
feeding
on
.growth
and
of
coregonid
Hydrobiol.,
Beih.
‘Ergebn.
Limnol.
In
press.
_…
,
Charlon
N.,«
Bergot P;,
1984. Rearing system for feeding fish
larVae
on
dry
Trial with carp (Cyprinus
carpio
larvae.
Aquaculture, gl; 1—9.
…
,_—__“
Dabrowski K.,
.l979.
enzymes in fish
digestion.'
E.
Styczÿnska—Jurewicz, T; Baokiel,
E.
Jaspers & G.
Persoone
(Eds), Cultivation of fish fry and
its
live
food,
European Mariculture Soc,
107—126.
223
Formulation of Practical 9£ Purified Diets.,
For
nutritional
studies
to
be
successful,ï
the
formulation of
a
purified
or
semi—purified
artificial
diet
is
essential;
In
the
case
of
Salmonids,
use
of
crystalline
amino—acid
based diets
have
proved successful
(Halver 1957),
whereas
in
the
Carp,
such
amino acid based diets
have
not
been
so°
A
number
of
comparisons between a whole protein diet
and
an
amino
acid diet have been undertaken.
In
the
adult
Carp,
differences
in
the
absorption of
amino
acids
were
reported
(Plakas et al°
1980).:
In
juvenile Carp, a comparison
between
-casein—bäEed—diet and an amino acid mixture diet
of
similar
composition showed that despite equivalent
intakes,
digestibility
and
transit
rates,
negative nitrogen
balance
was
noted
in Carp fed the latter diet
(Kaushik and Dabrowski
l983b),
Ammonia excretion was
low in those
fed
amino
acids,
suggesting
that
like
in
the
case
of
the
adult
Carp
(Murai et
al°
1984),
free
amino acids might be excreted by young CaËE
fËd such diets,
The
currently
successful
artificial
diets
for
Carp
larval
rearing have in their composition, variable amounts of single
cell
proteins and the effects of the contribution of
nucleic
acids
during
early growth is not yet well
understood.
Few
hypotheses
.on
specific
nutritional
needs,
especially
of
stomachless fish larvae have been put forward (Dabrowski
and
Kaushik
1982)
'and they require validation.
Lam
and
Sharma
(1985)
suggested
addition thyroxine
to
the
culture
milieu enhanced survival
and
growth of Carp.
Our
own
trials
with
dietary incorporation of thyroxine showed no beneficial
effects
and
Dabrowski,
unpublished).
the
currently
available
rearing
facilities
and
(CharlOn
and
Bergot 1984),
we
can
hope to obtain more basic
data
on
the nutritional needs of fish larvae
in
the
near
future.
REFERENCES
Bergot
P.,
Durante
H.,
1986.
The
effect
of
compound
dietS'
feeding
on
.growth
and
of
coregonid
Hydrobiol.,
Beih.
‘Ergebn.
Limnol.
In
press.
_…
,
Charlon
N.,«
Bergot P;,
1984. Rearing system for feeding fish
larVae
on
dry
Trial with carp (Cyprinus
carpio
larvae.
Aquaculture, gl; 1—9.
…
,_—__“
Dabrowski K.,
.l979.
enzymes in fish
digestion.'
E.
Styczÿnska—Jurewicz, T; Baokiel,
E.
Jaspers & G.
Persoone
(Eds), Cultivation of fish fry and
its
live
food,
European Mariculture Soc,
107—126.