. Materials andmethods2.1. Larval s

. Materials andmethods
2.1. Larval supply and rearing protocol
Beluga specimens used in the present study were obtained by
the hormonally-induced (LHRHa2) spawning of 2 females that were
fertilized with the milt of 3 males at the Shahid Marjani Sturgeon
Center (Gorgan, Iran). Eggs were incubated in Yushchenko incubators
at 11–12 °C in a closed freshwater recirculation system. After
eight days of incubation, hatching took place (hatching rate: 68%)
and 1800 newly hatched larvae (body weight, BW: 15.6 ± 0.7 mg;
total length, TL: 11.2 ± 0.4 mm) were placed in three 500 l circular
fiberglass tanks connected to a flow-through freshwater system.
Malformation rate at hatching (11.2 mm TL) was 6.1%. During the
larval rearing period, water temperature, dissolved oxygen, pH
and flow rate were 16.5 ± 0.2 °C, 10.7 ± 0.3 mg/l, 7.8 ± 0.1 and
5.7 ± 0.4 l/min, respectively. Larvaewere reared under natural photoperiod
(37°4′30.62″ N, 54°40′10.45″ E). All tank surfaces were
scrubbed and the bottom of the tank siphoned to remove uneaten
feed and feces 3 times a day.
The feeding protocol used for H. huso larval rearing fromhatching to
the juvenile stage is summarized in Fig. 1. In brief, larvae were fed by a
mixture of Artemia nauplii (EG, INVE, Belgium) and Daphnia sp. from12
to 25 dph (199.2–432.5 degree days post hatch, ddph) (500–800
nauplii/larvae/day). A short co-feeding phase based on Cladocerans
and a compound diet (BioMar, Denmark; D1—particle size = 0.5 mm)
was conducted from 25 to 30 dph (432.5–534 ddph), whereas from
this age onward, fish were fed only with the inert feed (BioMar,
Denmark; D2—particle size = 0.8 mm) at a feeding rate of 30 and
20% of stocked fish biomass respectively. The compound diet was
given to larvae from 4-6 times per day and feed ration and particle
size were progressively adjusted for fish size from 25 to 50 dph
(432.5–906.5 ddph).
Proximate composition (dry matter) of live prey (Artemia nauplii
and Daphnia sp.) was determined in 3 samples per type of live prey.
Crude protein was determined by the Kjeldahl method (N × 6.25)
using an automatic Kjeldahl system (Behrotest WD 40, Germany) and
crude fat content was determined by Soxhlet method (Folch et al.,
1957). Total protein and lipid content in Artemia were 65.6 ± 1.4%
and 15.1 ± 0.2%, respectively, whereas Daphnia sp. contained 52.6 ±
1.9% of proteins and 11.1 ± 0.1% of lipids. The proximate composition
of compound diets (D1 and D2) was 63 and 58% of total protein, 11
and 15% of total lipids, and 11.6 and 11.5% total carbohydrate respectively
(data provided by feed manufacturer).
2.2. Fish growth measurements and sampling schedule
In order to determine larval growth in weight (BW) and total length
(TL), fish (n = 40)were daily sampled randomly prior to feeding in the
morning using a pipette with a large opening from hatching to 18 dph
(306 ddph), whereas samples were collected every 2 days from 18 to
50 dph (306–906.5 ddph). Sampled larvae were sacrificed with an
overdose of tricaine methanosulphonate (MS-222, Sigma-Aldrich,

ผลลัพธ์ (อังกฤษ) 1:

. materials andmethods
2.1. larval supply and rearing protocol
beluga specimens used in the present study were obtained by
the hormonally-induced (lhrha2) spawning of 2 females that were
fertilized with the milt of 3 males at the shahid marjani sturgeon
center (gorgan, iran). . eggs were incubated in yushchenko incubators
at 11-12 ° c in a closed freshwater recirculation system. after
eight days of incubation, hatching took place (hatching rate: 68%)
and 1800 newly hatched larvae (body weight, bw: 15.6 ± 0.7 mg;
total length, tl: 11.2 ± 0.4 mm) were placed in three 500 l circular.
fiberglass tanks connected to a flow-through freshwater system.
malformation rate at hatching (11.2 mm tl) was 6.1%. during the
larval rearing period, water temperature, dissolved oxygen, ph
.and flow rate were 16.5 ± 0.2 ° c, 10.7 ± 0.3 mg / l, 7.8 ± 0.1 and
5.7 ± 0.4 l / min, respectively. larvaewere reared under natural photoperiod
(37 ° 4'30 .62 "n, 54 ° 40'10 .45" e). all tank surfaces were
scrubbed and the bottom of the tank siphoned to remove uneaten
feed and feces 3 times a day.
the feeding protocol used for h. huso larval rearing fromhatching to
the juvenile stage is summarized in fig. One. in brief, larvae were fed by a
mixture of artemia nauplii (eg, inve, belgium) and daphnia sp. from12
to 25 dph (199.2-432.5 degree days post hatch, ddph) (500-800
nauplii / larvae / day). a short co-feeding phase based on cladocerans
and a compound diet (biomar, denmark; d1-particle size = 0.5 mm)
was conducted from 25 to 30 dph (432.5-534 ddph),.whereas from
this age onward, fish were fed only with the inert feed (biomar,
denmark; d2-particle size = 0.8 mm) at a feeding rate of 30 and
20% of stocked fish biomass respectively. the compound diet was
given to larvae from 4-6 times per day and feed ration and particle
size were progressively adjusted for fish size from 25 to 50 dph
(432.5-906.5 ddph).
.proximate composition (dry matter) of live prey (artemia nauplii
and daphnia sp.) was determined in 3 samples per type of live prey.
crude protein was determined by the kjeldahl method (n × 6.25)
using an automatic kjeldahl system (. behrotest wd 40, germany) and
crude fat content was determined by soxhlet method (folch et al.,
1957). total protein and lipid content in artemia were 65.6 ± 1.4%
.and 15.1 ± 0.2%, respectively, whereas daphnia sp. contained 52.6 ±
1.9% of proteins and 11.1 ± 0.1% of lipids. the proximate composition
of compound diets (d1 and d2) was 63 and 58% of total protein, 11
and 15% of total lipids, and 11.6 and 11.5% total carbohydrate respectively
(data provided by feed manufacturer).
2.2. fish growth measurements and sampling schedule
.in order to determine larval growth in weight (bw) and total length
(tl), fish (n = 40) were daily sampled randomly prior to feeding in the
morning using a pipette with a large opening from hatching to 18 dph
(. 306 ddph), whereas samples were collected every 2 days from 18 to
50 dph (306-906.5 ddph). sampled larvae were sacrificed with an
overdose of tricaine methanosulphonate (ms-222,.

ผลลัพธ์ (อังกฤษ) 3:

.Materials andmethods
2.1.Larval supply and rearing protocol
Beluga specimens used in the present study were obtained by the
hormonally-induced (LHRHa 2) spawning of
2 females that were fertilized with the milt of 3 males at the Shahid Marjani Sturgeon
Center (Gorgan, Iran) .Eggs were incubated in Yushchenko
incubators at 11 - 12 °C freshwater recirculation in a closed system.After
eight days of incubation, hatching took place (hatching Rate: 68 % ), and 1800
newly hatched larvae (body weight, BW: 15.6 ±0.7 mg;
total length, TL: 11.2±0.4 mm) were placed in three circular 500 L
fiberglass tanks connected to a flow-through freshwater system.
Malformation at hatching rate (11.2 mm TL) was 6.1 %. The During
larval rearing period, water temperature, dissolved oxygen, pH
Flow rate were 0.2 and 16.5± °C, 10.7 ±0.3 mg/l, 7.8
5.7± ±0.1 and 0.4 L/Min, respectively. Larvaewere reared under natural photoperiod
(37 °4 ′ ′ ′ N 30.62, 10.45 54 °40 ′ ′ ′ E) .
All tank surfaces were scrubbed and the bottom of the tank siphoned to remove uneaten feed and feces
3 times a day.
The feeding protocol used for H.huso larval rearing to fromhatching
The juvenile stage is summarized in Fig. 1. In brief, larvae were fed by a mixture of
Artemia nauplii (EG, INVE, Belgium) and Daphnia sp. From 12 to 25 dph
(199.2 - 432.5 degree days post hatch, ddph) (500 - 800
nauplii/larvae/day) .A short co-feeding phase based on Cladocerans
and a compound diet (BioMar, Denmark ; D 1 - particle size = 0.5 mm)
was conducted from 25 to 30 dph (432.5 - 534 ddph),whereas
from this age onward, fish were fed with only the inert feed (BioMar,
Denmark ; D 2 - particle size = 0.8 mm) at a feeding rate of 30 and 20% of stocked fish
biomass respectively.
The compound diet was given to larvae from 4 - 6 times per day and feed ration and
particle size were progressively adjusted for fish size from 25 to 50 dph
(432.5 - 906.5 ddph) .
Proximate composition (dry matter) of live prey (Artemia nauplii and
Daphnia sp.) was determined in 3 samples per type of live prey.
Crude Kjeldahl protein was determined by the method (N × 6.25)
Kjeldahl using an automatic system (Behrotest WD 40, Germany), and
crude fat content was determined by Soxhlet method (Folch et al., 1957
). Total protein and lipid content in Artemia were 65.6± 1.4%
±0.2 and 15.1 percent, respectively, whereas Daphnia sp. contained 52.6
1.9± ±11.1 percent of proteins and 0.1% of lipids. The
proximate composition of compound diets (D D 1 and 2) was 63 and 58% of total protein, 11
and 15% of total lipids, and 11.6 and 11.5 per cent respectively
total carbohydrate (data provided by feed manufacturer) .
2.2.Fish growth measurements and sampling schedule
In larval growth in order to determine weight (BW) total length and
(TL), fish (N = 40) were randomly sampled daily
prior to feeding in the morning using a pipette with a large opening from hatching to 18 dph
(306 ddph), whereas samples were collected every 2 days from 18 to 50 dph
(306 - 906.5 ddph). Sampled larvae were sacrificed with an overdose of tricaine
methanosulphonate (MS - 222,Sigma - Aldrich,