236
Aquacültüre Of Cyprinids
intermittent1y : short (0.1 s) periods of activity, mostly of the pectoral
fins but to a varying degree of the body, are alternated with longer (0.2 —
0.4 s) periods of rest. A typical attack sequence lasts 0.5 s. No 8
attack posture is formed. All times are relative to the
opening, swimming starts 10 ms earlier. This may involve large amplitude
movements
of
the body. During mouth opening the pectoral fins become folded
against the body. The mouth is closed again after 20 ms. The pectoral fins
are
to the body (braking?). Opening of the
valve occurs after 8 ms, Closure after about 0.5 3. The Chance that a sphere—
like prèy'ehtérs the mouth is maximized if the predator tries to ingest
through the center of its mouth aperture. The accuracy of aiming is defined
as
the distance, perpendicular to the length axis of the fish, between the
centre
of the m0uth aperture at the moment of prey intake and the centre
mass
of
the prey at the
start
of the snap. With a mathematical model a
tion between accuracy of aiming (expressed in mouth radius units) and feeding
sucCess can be calculated. Calculated feeding success from aiming
with meaSured total feeding success. Apparently this model adequately
dict5 the feeding success from
the time Scale
suction proceSs Artemia nauplii are immobile. The energy used in a-snapran
be estimated from the kinetic energy of the water sucked into the mouth and
of
the swimming fish. The volume flow until the moment of opening of
opercular valve can be
from films with a view from below
aside. This volume is 0.2 mm
for a 7 mm carp larva and maximal water Veloci—
ty is 0.28 m/s (reached in 7 ms). As total énergy_(including swimming, fri—
ction and metabolic efficiency) is less than 0.12 of the energetic content
of
the prey,
energetic Considérations will be unimportant in the
"
“
CULTURE 01“ ‘Tihca ‘tincà IN CARPf5PONDSEGRVGŒREK. In£and «mn—mu Imm—
zîc,
iP0£ANÛ=
%‘ 3
Three PQÜdS were 3tÔëkëd
Tinoä tinca Only and andtheï three
with the same number of
Spawning was
in each
000
of
fr_y Were" fîghéd. Their
the .t‘_bÜ:al£ production—, of
was
in
than in ponde 5w‘ith ten‘ch
“only; The»?
stôbkig density“ tha-“
with a
density of
fry
30—90 g_: productioû.was 90—250 Kg/ha. The biggest production was
ponds stocked with 10 000 indiv./ha of carp, in which the fish were fed with
pellets. During these two seasons in all ponds zooplankton was
vae
We‘re“ 1n pondsst0cked
50001—
ofcarp fîfÿ- :: 7Th1fe‘ir wé
cor—
.
related with theäynamlcs _‘ähd
:vëfy
species for
The composition
in pondS
With
andtenchfry
°“c1‘eÿén‘d‘ëid
Thé
‘il—lower whentherewere mor e"r 2enüf
'b1e thatt each
dt iîli'z‘ed
aîül
*
w1
…_«»
"
-.«'
s‘
ë‘î—a
“E‘-75:
:3;»_
.
35 ;
',
:
”
‘:
'…
\
…
—…
11
1
1
11 11111 11
‘
111
1____
___…
……__11 ___1_____.
Aquacültüre Of Cyprinids
intermittent1y : short (0.1 s) periods of activity, mostly of the pectoral
fins but to a varying degree of the body, are alternated with longer (0.2 —
0.4 s) periods of rest. A typical attack sequence lasts 0.5 s. No 8
attack posture is formed. All times are relative to the
opening, swimming starts 10 ms earlier. This may involve large amplitude
movements
of
the body. During mouth opening the pectoral fins become folded
against the body. The mouth is closed again after 20 ms. The pectoral fins
are
to the body (braking?). Opening of the
valve occurs after 8 ms, Closure after about 0.5 3. The Chance that a sphere—
like prèy'ehtérs the mouth is maximized if the predator tries to ingest
through the center of its mouth aperture. The accuracy of aiming is defined
as
the distance, perpendicular to the length axis of the fish, between the
centre
of the m0uth aperture at the moment of prey intake and the centre
mass
of
the prey at the
start
of the snap. With a mathematical model a
tion between accuracy of aiming (expressed in mouth radius units) and feeding
sucCess can be calculated. Calculated feeding success from aiming
with meaSured total feeding success. Apparently this model adequately
dict5 the feeding success from
the time Scale
suction proceSs Artemia nauplii are immobile. The energy used in a-snapran
be estimated from the kinetic energy of the water sucked into the mouth and
of
the swimming fish. The volume flow until the moment of opening of
opercular valve can be
from films with a view from below
aside. This volume is 0.2 mm
for a 7 mm carp larva and maximal water Veloci—
ty is 0.28 m/s (reached in 7 ms). As total énergy_(including swimming, fri—
ction and metabolic efficiency) is less than 0.12 of the energetic content
of
the prey,
energetic Considérations will be unimportant in the
"
“
CULTURE 01“ ‘Tihca ‘tincà IN CARPf5PONDSEGRVGŒREK. In£and «mn—mu Imm—
zîc,
iP0£ANÛ=
%‘ 3
Three PQÜdS were 3tÔëkëd
Tinoä tinca Only and andtheï three
with the same number of
Spawning was
in each
000
of
fr_y Were" fîghéd. Their
the .t‘_bÜ:al£ production—, of
was
in
than in ponde 5w‘ith ten‘ch
“only; The»?
stôbkig density“ tha-“
with a
density of
fry
30—90 g_: productioû.was 90—250 Kg/ha. The biggest production was
ponds stocked with 10 000 indiv./ha of carp, in which the fish were fed with
pellets. During these two seasons in all ponds zooplankton was
vae
We‘re“ 1n pondsst0cked
50001—
ofcarp fîfÿ- :: 7Th1fe‘ir wé
cor—
.
related with theäynamlcs _‘ähd
:vëfy
species for
The composition
in pondS
With
andtenchfry
°“c1‘eÿén‘d‘ëid
Thé
‘il—lower whentherewere mor e"r 2enüf
'b1e thatt each
dt iîli'z‘ed
aîül
*
w1
…_«»
"
-.«'
s‘
ë‘î—a
“E‘-75:
:3;»_
.
35 ;
',
:
”
‘:
'…
\
…
—…
11
1
1
11 11111 11
‘
111
1____
___…
……__11 ___1_____.