TECHNOLOGY FOR ARTIFICIAL SPAWNING OF TECHNOLOGY FOR ARTIFICIAL SPAWNING OF STURGEONS SPECIESSTURGEONS SPECIES

• ObjectObject• The present technology is after to achieve by artificial spawning of The present technology is after to achieve by artificial spawning of

parental species of sturgeons.parental species of sturgeons.• Objectives pursued:Objectives pursued:• Providing descendants for rehabilitating wild population of Providing descendants for rehabilitating wild population of

sturgeons from Danube river;sturgeons from Danube river;• Inserting sturgeons species in aquaculture;Inserting sturgeons species in aquaculture;• Fries achieved from pure species of sturgeons will form the basis Fries achieved from pure species of sturgeons will form the basis

of genetic fond reared strictly under conditions of aquaculture of genetic fond reared strictly under conditions of aquaculture which will contribute to its development and protection of which will contribute to its development and protection of sturgeon stocks from natural environment.sturgeon stocks from natural environment.

• Area of implementationArea of implementation• Technology for artificial spawning of parental species of sturgeons Technology for artificial spawning of parental species of sturgeons

is intended to economical agents that have the main activity is intended to economical agents that have the main activity fishing and aquaculture. fishing and aquaculture.

• Technological system for artificial spawning of parental Technological system for artificial spawning of parental species of sturgeonsspecies of sturgeons

• Technological system of artificial spawning will be apportion Technological system of artificial spawning will be apportion depending on production capacity agreed by costumer, and depending on production capacity agreed by costumer, and will ensure by its capacity the spawning in series of two will ensure by its capacity the spawning in series of two families of beluga, five families of Russian sturgeon, 20 families of beluga, five families of Russian sturgeon, 20 families of sevruga and 20 families of starlet.families of sevruga and 20 families of starlet.

• Correlate with the capacity for incubation, technological Correlate with the capacity for incubation, technological system will be framed by a pumping group, modules for system will be framed by a pumping group, modules for standing and maturation of breeders, modules for standing and maturation of breeders, modules for incubation of embrionated eggs and modules for standing incubation of embrionated eggs and modules for standing larvae whose sizing and technical characteristics are larvae whose sizing and technical characteristics are following following

No.Crt.

Type of facility No. of units Technical features

1. Pumping system 2 Q - 110 m3 /h, înălţimea de pompare 36m

2. Module for standing breeders 4 Shape: circular;Diameter – 6 mHeight – 1.2 mCapacity – 22.6 m3 Stocking capacity – 150 kgStocking capacity – 150 kg

3. Modules for maturation of breeders 4 Rectangular form: 2,8 x 0,61 x 0,61

4. Modules for hatching fertilized eggs 40 Tipe: Brates, capacity 15 lMinimum capacity of storage 300 g

5. Modules for standing larvae 36 Rectangular form: 2,2 x 0,42 x 0,17

• 3. DESCRIPTION OF TECHNOLOGY3. DESCRIPTION OF TECHNOLOGY• Technology for artificial breeding and rearing of parental species Technology for artificial breeding and rearing of parental species

of sturgeons imply the passing through of following phases:of sturgeons imply the passing through of following phases:• breeders catch;breeders catch;• evaluation of phenotypic characters;evaluation of phenotypic characters;• assessment of reproductive condition;assessment of reproductive condition;• transportation and standing;transportation and standing;• induction of sexual cells maturation;induction of sexual cells maturation;• gathering sexual products;gathering sexual products;• fertilization;fertilization;• incubation of sexual products in special installed enclosures;incubation of sexual products in special installed enclosures;• standing larvae;standing larvae;• sacking and transportation of larvae;sacking and transportation of larvae;• rearing larvae up on achieving adult-like phenotypic characters; rearing larvae up on achieving adult-like phenotypic characters;

• Capturing and standing breeders on fishing areaCapturing and standing breeders on fishing area• Sturgeon breeders needed for stations of spawning and rearing Sturgeon breeders needed for stations of spawning and rearing

fries will be achieved by fishing, during spring migration, at fries will be achieved by fishing, during spring migration, at temperature of Danube waters of 10 – 22 0C.temperature of Danube waters of 10 – 22 0C.

• Catch will be achieved with decline seines having mash size of Catch will be achieved with decline seines having mash size of 60 – 100 mm.60 – 100 mm.

• Assessment of phenotypic characters and reproductive Assessment of phenotypic characters and reproductive conditioncondition

• Sturgeon breeders will be examined immediately after catch to Sturgeon breeders will be examined immediately after catch to evaluate phenotypic characters and sex determination. evaluate phenotypic characters and sex determination. Examination in the field for purpose to determining sex and Examination in the field for purpose to determining sex and maturation stage will be accomplished by internal palpation.maturation stage will be accomplished by internal palpation.

• Transporting and standing breedersTransporting and standing breeders• Will be used fiber glass tanks of different capacities, well Will be used fiber glass tanks of different capacities, well

sealed, sized depending on sturgeons species and provided sealed, sized depending on sturgeons species and provided with installation of aeration.with installation of aeration.

• In case of a transportation tank well equipped, stocking density In case of a transportation tank well equipped, stocking density can be almost 150 kg/m3. can be almost 150 kg/m3.

• Hormonal inductionHormonal induction..• The product NERESTIN 5A will be used for stimulation. Induction of The product NERESTIN 5A will be used for stimulation. Induction of

complete ovulation and elimination of sexual products will be complete ovulation and elimination of sexual products will be accomplished by dosing two injections with hormonal preparation. accomplished by dosing two injections with hormonal preparation. Time interval between initial injection, prime one and the second Time interval between initial injection, prime one and the second injection, decisive one is of 12 hours.injection, decisive one is of 12 hours.

• Doses of synthetic hormones will be:Doses of synthetic hormones will be:– 0.2 ml/kg of body weight on females;0.2 ml/kg of body weight on females;– 0.1 ml/kg of body weight on males.0.1 ml/kg of body weight on males.

• Gathering sexual productsGathering sexual products• Gathering sexual products on female start at the time when it Gathering sexual products on female start at the time when it

starts to eliminate a consistently quantity of limy eggs.starts to eliminate a consistently quantity of limy eggs.• The method for gathering eggs will consist in abdominal palpation The method for gathering eggs will consist in abdominal palpation

or so called mode of “milking”. In case that female does not or so called mode of “milking”. In case that female does not release eggs it will be incised and eggs will be gathering by slowly release eggs it will be incised and eggs will be gathering by slowly palpation. In males sperm will be collected when the females palpation. In males sperm will be collected when the females begin to eliminate sticky eggs either with a few hours before begin to eliminate sticky eggs either with a few hours before these. Gathering sperm will be accomplished with syringes fitted these. Gathering sperm will be accomplished with syringes fitted with tubes of 5 – 6 cm. with tubes of 5 – 6 cm.

• FertilizationFertilization• Once collected, the eggs from a single female will be equally Once collected, the eggs from a single female will be equally

spread in jars in which is to make the fertilization.spread in jars in which is to make the fertilization.• Currently 1 kg of eggs uses 10 ml of sperm with viability of 90 Currently 1 kg of eggs uses 10 ml of sperm with viability of 90

%.%.• Time for fertilization will be of 3 minutes. After fertilization, Time for fertilization will be of 3 minutes. After fertilization,

eggs will be degumming. For degumming use a single process, eggs will be degumming. For degumming use a single process, i.e. stopping the sticky surface of fertilized eggs with mud.i.e. stopping the sticky surface of fertilized eggs with mud.

• Hatching eggsHatching eggs• Hatching eggs will begin immediately after degumming, with Hatching eggs will begin immediately after degumming, with

the passage into the hatchery devices. Hatching duration vary the passage into the hatchery devices. Hatching duration vary with species and within the same species according to daily with species and within the same species according to daily average temperature.average temperature.

• On sturgeons, optimal temperature for hatching is 13 – 14 0C. On sturgeons, optimal temperature for hatching is 13 – 14 0C. Average time duration of embryogenesis on these values of Average time duration of embryogenesis on these values of water temperature is around of 5 – 7 days. These temperatures water temperature is around of 5 – 7 days. These temperatures provide good conditions for embryonic development and do not provide good conditions for embryonic development and do not facilitate mould development.facilitate mould development.

• Mould control during hatching time will be accomplish by Mould control during hatching time will be accomplish by bathing eggs, directly in hatcheries, with malachite green 67 bathing eggs, directly in hatcheries, with malachite green 67 ppm for 30 seconds in two times, after 12 and 24 hours from ppm for 30 seconds in two times, after 12 and 24 hours from fertilization. fertilization.

• Sampling and standing larvaeSampling and standing larvae• Sampling hatched larvae is accomplished continuously on cushion Sampling hatched larvae is accomplished continuously on cushion

of water, in individual tanks for gathering. Gathering tank is fitted of water, in individual tanks for gathering. Gathering tank is fitted with a nytal cage having mesh size of 0.3 – 0.5 mm to constrict the with a nytal cage having mesh size of 0.3 – 0.5 mm to constrict the larvae. Stocking density will be of 40 – 60 ex/l. Water flow in tanks larvae. Stocking density will be of 40 – 60 ex/l. Water flow in tanks for standing of larvae will be adjusted to 5 l/min. Larvae will stay in for standing of larvae will be adjusted to 5 l/min. Larvae will stay in these enclosures for 3 – 5 days.these enclosures for 3 – 5 days.

• Growth of larvae up on achieving adult-like phenotypic Growth of larvae up on achieving adult-like phenotypic characterscharacters

• Stocking rateStocking rate• Larvae achieved from each female are stoked independently on Larvae achieved from each female are stoked independently on

rearing enclosures. Stoking rate is 10.000 ex/m3 and is determined rearing enclosures. Stoking rate is 10.000 ex/m3 and is determined taking into account technological losses for rearing phase which in taking into account technological losses for rearing phase which in general are estimated on 30 %.general are estimated on 30 %.

• Preparing of rearing modules and stoking of larvae.Preparing of rearing modules and stoking of larvae.• Preparing of rearing enclosures is made with 48 hours afore Preparing of rearing enclosures is made with 48 hours afore

stoking.stoking.• Enclosures are rigorously cleaned with Germostop solution 10 %, Enclosures are rigorously cleaned with Germostop solution 10 %,

this solution is keep on for an hour and then banished by repeated this solution is keep on for an hour and then banished by repeated wash off.wash off.

• The height of water column in rearing enclosures is adjusted to 20 The height of water column in rearing enclosures is adjusted to 20 cm. cm.

• FeedingFeeding• Rearing of larvae up to outlining phenotypic characters Rearing of larvae up to outlining phenotypic characters

conformable with adults is achieved on account of a feeding conformable with adults is achieved on account of a feeding schedule involving deliver of live food and blended yolk of egg in schedule involving deliver of live food and blended yolk of egg in first 5 – 7 days of growth and then a composite diet composed of first 5 – 7 days of growth and then a composite diet composed of natural food and forage.natural food and forage.

• Combinations of natural feeding stuffs charged are the following:Combinations of natural feeding stuffs charged are the following:• 90 % 90 % Tubifex sp.Tubifex sp. and 10 % zooplankton and 10 % zooplankton• 50 % 50 % Tubifex sp.Tubifex sp. and 50 % fresh or saline zooplankton and 50 % fresh or saline zooplankton• Feeding rate is fixed daily depending on weight of stock. Feeding rate is fixed daily depending on weight of stock.

Delivering rate in 24 hours is determined as percentage of 100 % Delivering rate in 24 hours is determined as percentage of 100 % from stocking weight on that day.from stocking weight on that day.

• Equal parts from this rate are delivered at every 3 hours day and Equal parts from this rate are delivered at every 3 hours day and night.night.

• Feeding of larvae using natural live food in a composite diet with Feeding of larvae using natural live food in a composite diet with forage will imply the use of following feeding schedule that will forage will imply the use of following feeding schedule that will allow gradually passing to a feeding based exclusively on forage:allow gradually passing to a feeding based exclusively on forage:

• first 5 days: 5 % zooplankton, 85 % benthos, 10 % forage;first 5 days: 5 % zooplankton, 85 % benthos, 10 % forage;• next 5 days: 5 % zooplankton, 60 % benthos, 35 % forage;next 5 days: 5 % zooplankton, 60 % benthos, 35 % forage;• next 5 days: 5 % zooplankton, 45 % benthos, 50 % forage;next 5 days: 5 % zooplankton, 45 % benthos, 50 % forage;• next 5 days: 5 % zooplankton, 10 % benthos, 85 % forage;next 5 days: 5 % zooplankton, 10 % benthos, 85 % forage;• After that feeding will be assure only by forage. After that feeding will be assure only by forage.

Growth gain to be obtained from the stages of development up to

outlining adult-like phenotypic characters are the following:

Variant Spor de creştere - g

Parental species of sturgeons 10 zile 20 zile 30 zile 40 zile

Huso huso - beluga 0,9 2 5,2 8

Acipenser gueldenstaedti – Russian sturgeon 0,5 1,6 4 5

Acipenser stellatus – sevruga 0,3 1,5 3 3

Acipenser ruthenus – starlet 0,15 0,8 1,5 2