TECHNOLOGY FOR ARTIFICIAL SPAWNING OFTECHNOLOGY FOR ARTIFICIAL SPAWNING OFSTIZOSTEDION LUCIOPERCASTIZOSTEDION LUCIOPERCA SPECIES – PIKEPERCH SPECIES – PIKEPERCH

• TECHNOLOGY DISPLAYTECHNOLOGY DISPLAY• ObjectObject• The elaborated technology is after controlled The elaborated technology is after controlled

spawning of spawning of Stizostedion luciopercaStizostedion lucioperca – – pikeperch, towards redressing its natural pikeperch, towards redressing its natural populations and inserting it on aquaculture.populations and inserting it on aquaculture.

• Area of implementationArea of implementation

• Implicit costumers of spawning technology are Implicit costumers of spawning technology are economical agents that have the main activity economical agents that have the main activity

fishing and aquaculture.fishing and aquaculture.

Technological system for artificial spawning ofTechnological system for artificial spawning ofStizostedion luciopercaStizostedion lucioperca – pikeperch – pikeperch

• In correlation with capacity for incubation, technological In correlation with capacity for incubation, technological system will be constituted by an assembly of earthen system will be constituted by an assembly of earthen ponds: wintering ponds, standing-wintering ponds, ponds: wintering ponds, standing-wintering ponds, standing-maturation ponds, controlled spawning ponds, standing-maturation ponds, controlled spawning ponds, modules for standing and maturation of breeders, modules modules for standing and maturation of breeders, modules for incubation of embrionated eggs and for standing larvae.for incubation of embrionated eggs and for standing larvae.

• Spawning ponds. Spawning ponds. These are small surface ponds (0.25 – These are small surface ponds (0.25 – 0.5 ha), with continuously supply and discharge of water, 0.5 ha), with continuously supply and discharge of water, hard bottom and water depth of 0.70 – 0.90 m, rarely 1 – hard bottom and water depth of 0.70 – 0.90 m, rarely 1 – 1.2 m. In these ponds are fixed pallets (nests) on which 1.2 m. In these ponds are fixed pallets (nests) on which breeders will spawn. breeders will spawn.

• Fixing pallets on Fixing pallets on spawning pond is carried spawning pond is carried out 2 – 3 m from bank (in out 2 – 3 m from bank (in order to observe the order to observe the moment of spawning) moment of spawning) and the distance and the distance between pallets on the between pallets on the side of pond is of 8 – 10 side of pond is of 8 – 10 m (Fig. 1). m (Fig. 1).

• The installation for incubation of pikeperch eggs is aimed at The installation for incubation of pikeperch eggs is aimed at achieving optimum condition for incubation of eggs. Is achieving optimum condition for incubation of eggs. Is assured water supply, maintenance of a optimum depth, assured water supply, maintenance of a optimum depth, treatment of eggs and discharge water individualized from treatment of eggs and discharge water individualized from each hatchery.each hatchery.

• Installation constituentInstallation constituent• Installation consists of following subassemblies:Installation consists of following subassemblies:• overall preparedness hatching;overall preparedness hatching;• installation of water supply for hatcheries;installation of water supply for hatcheries;• hatchery;hatchery;• support for hatcheries;support for hatcheries;• installation for water discharge.installation for water discharge.

• Overall preparedness Overall preparedness hatchinghatching

• Consists of:Consists of:• installation for installation for

technological water supply;technological water supply;• trays for fertilization;trays for fertilization;• support frames for eggs;support frames for eggs;• platform support.platform support.• Nucet type hatchery use Nucet type hatchery use

for incubation of for incubation of pikeperch eggspikeperch eggs

• Nucet type hatchery is Nucet type hatchery is made up of a metal box made up of a metal box with dimensions 60 × 60 × with dimensions 60 × 60 × 55 cm in which introduces a 55 cm in which introduces a cage made of Nytal bolt cage made of Nytal bolt having mesh size of 200 μm having mesh size of 200 μm and dimensions of 52 × 52 and dimensions of 52 × 52 × 46 cm. Hatchery has a × 46 cm. Hatchery has a volume of 180 l and a volume of 180 l and a maximum incubation maximum incubation capacity of 1.5 kg of eggs. capacity of 1.5 kg of eggs.

• The module for standing of The module for standing of breeders is used for breeders is used for breeders during the period breeders during the period before spawning.before spawning.

• Composition of unit for Composition of unit for standing of breedersstanding of breeders

• The module consists of the The module consists of the following major sub-following major sub-assemblies:assemblies:

• parallelepipedous tank parallelepipedous tank with useful volume of 4.0 with useful volume of 4.0 m3;m3;

• installation of discharge installation of discharge and adjustment of water and adjustment of water level;level;

• installation of water installation of water supply. supply.

DESCRIPTION OF TECHNOLOGY DESCRIPTION OF TECHNOLOGY

• The technology for controlled-artificial spawning The technology for controlled-artificial spawning and rearing of larvae of and rearing of larvae of Stizostedion luciopercaStizostedion lucioperca species involves travel along following phases:species involves travel along following phases:

• Assurance of breeders stock;Assurance of breeders stock;• Evaluation of phenotypic characters and sex Evaluation of phenotypic characters and sex

determination;determination;• Standing, pre-maturation of breeders;Standing, pre-maturation of breeders;• Assessment of reproductive condition;Assessment of reproductive condition;• Placing breeders in spawning ponds;Placing breeders in spawning ponds;• Spawning;Spawning;• Sampling the pallets;Sampling the pallets;• Incubation of sexual products in specially Incubation of sexual products in specially

prepared enclosures;prepared enclosures;• Packing and transportation of fry.Packing and transportation of fry.

• Assurance of breeders stock.Assurance of breeders stock.• Pikeperch breeders needed for stations of production and rearing Pikeperch breeders needed for stations of production and rearing

of fry come both in natural environments, by catching them in of fry come both in natural environments, by catching them in early spring, and stocks reared in farms especially for this goal.early spring, and stocks reared in farms especially for this goal.

• Preliminary evaluation of breedersPreliminary evaluation of breeders• Pikeperch breeders will be assessed immediately after catch for Pikeperch breeders will be assessed immediately after catch for

evaluation of phenotypic characters and determination of sex. evaluation of phenotypic characters and determination of sex. Selected breeders have length of 30 – 50 cm and weight of 1.0 – Selected breeders have length of 30 – 50 cm and weight of 1.0 – 3.0 kg.3.0 kg.

• Breeders must display body integrity, biological qualities and a Breeders must display body integrity, biological qualities and a good physiological shape.good physiological shape.

• Assessment of reproductive conditionAssessment of reproductive condition• The method of assessing both the maturation stage and polarity The method of assessing both the maturation stage and polarity

factor involves collecting a minimum of 5 eggs from posterior part factor involves collecting a minimum of 5 eggs from posterior part of ovary by practicing a puncture.of ovary by practicing a puncture.

• For determination of nucleus or germinal vesicle position, ova will For determination of nucleus or germinal vesicle position, ova will be cut-off exactly along the axis of animal-vegetal pole. After this be cut-off exactly along the axis of animal-vegetal pole. After this operation, nucleus position will be observed and evaluated.operation, nucleus position will be observed and evaluated.

• For determining the polarity factor measured under the For determining the polarity factor measured under the stereoscope distance from the top of germinal vesicle to animal stereoscope distance from the top of germinal vesicle to animal pole and the distance from animal pole to vegetal pole.pole and the distance from animal pole to vegetal pole.

• Small values of the coefficient indicated a high degree of Small values of the coefficient indicated a high degree of polarization for ova so an advanced stage IV of maturation. polarization for ova so an advanced stage IV of maturation.

• After evaluating After evaluating reproductive condition, reproductive condition, females who are in females who are in advanced maturing stage advanced maturing stage are selected and populated are selected and populated in spawning pond, in which in spawning pond, in which are fixed the pallets. In the are fixed the pallets. In the pond are also populated the pond are also populated the males that release a few males that release a few drops of sperm on a slight drops of sperm on a slight palpation of abdomen. In a palpation of abdomen. In a pond of a hectare are pond of a hectare are release 10 – 12 females and release 10 – 12 females and as many males. The batch as many males. The batch has to be more uniform has to be more uniform choosing breeders of close choosing breeders of close size. size.

• Spawning;Spawning;• Spawning takes place in the Spawning takes place in the

early hours of sunny early hours of sunny mornings.mornings.

• The nests with eggs are The nests with eggs are getting away from the getting away from the spawning pond on the bank, spawning pond on the bank, carefully detached from the carefully detached from the pallets and are carrying in pallets and are carrying in barrows with water to the barrows with water to the spawning station (Fig. 7).spawning station (Fig. 7).

• Incubation pikeperch Incubation pikeperch eggs.eggs.

• The nests with pikeperch The nests with pikeperch eggs are placed carefully in eggs are placed carefully in Nytal cages from Nucet Nytal cages from Nucet hatcheries and ensure hatcheries and ensure continuously water supply continuously water supply to a flow of 8 l/min. to a flow of 8 l/min.

• Females under the II and III maturation stage are Females under the II and III maturation stage are hormonal stimulated and spawned artificiallyhormonal stimulated and spawned artificially

• Hormonal stimulationHormonal stimulation• For hormonal stimulation of pikeperch will be used pituitary For hormonal stimulation of pikeperch will be used pituitary

extract of carp. Females are stimulated with 5 – 15 mg/kg extract of carp. Females are stimulated with 5 – 15 mg/kg of body weight depending on maturation stage and for of body weight depending on maturation stage and for males are used 3 – 5 mg/kg of body weight.males are used 3 – 5 mg/kg of body weight.

• Injection is carried out either in dorsal muscle either on the Injection is carried out either in dorsal muscle either on the base of pectoral fin. After injection, breeders separated on base of pectoral fin. After injection, breeders separated on sex are placed in tanks for maturation on hatchery station. sex are placed in tanks for maturation on hatchery station. Ovulation can be achieved after about 48 hours from Ovulation can be achieved after about 48 hours from injection.injection.

• Gathering eggs and artificial fertilization. Gathering eggs and artificial fertilization. Gathering Gathering eggs is done in females perfectly mature by slightly eggs is done in females perfectly mature by slightly palpation of abdomen.palpation of abdomen.

• From a pikeperch female is gathering a quantity of eggs From a pikeperch female is gathering a quantity of eggs between 150 and 200 ml. between 150 and 200 ml.

• FertilizationFertilization

• Eggs gather from a single Eggs gather from a single female are fertilized female are fertilized individually with a mixture of individually with a mixture of sperm from 5 – 6 males. sperm from 5 – 6 males. Quantity of sperm used is 2 Quantity of sperm used is 2 ml for a portion of 200 ml of ml for a portion of 200 ml of eggs.eggs.

• The mixture is homogenized The mixture is homogenized then adds the fertilizer liquid. then adds the fertilizer liquid. Time for fecundation is about Time for fecundation is about 3 – 5 minutes. After passing 3 – 5 minutes. After passing the three minutes, eggs are the three minutes, eggs are spread on support frames of spread on support frames of Nytal. Nytal.

• Incubation of eggsIncubation of eggs• Incubation of eggs will start with introduction and attach of frames Incubation of eggs will start with introduction and attach of frames

in the Nucet hatcheries. Duration of hatching is variable in the Nucet hatcheries. Duration of hatching is variable depending on daily mean temperature: 11 days at 13 0C, 4 – 5 depending on daily mean temperature: 11 days at 13 0C, 4 – 5 days at temperature of 14 – 15 0C.days at temperature of 14 – 15 0C.

• For pikeperch, optimal temperature for incubation is 15 0C. Mean For pikeperch, optimal temperature for incubation is 15 0C. Mean duration of embryogenesis on these values of water temperature duration of embryogenesis on these values of water temperature is about 5 – 6 days.is about 5 – 6 days.

• The flow of water supply on hatcheries up to gastrulating stage of The flow of water supply on hatcheries up to gastrulating stage of eggs will be adjusted for such a way as to create a stream of eggs will be adjusted for such a way as to create a stream of water that does not produce displacement of eggs from the water that does not produce displacement of eggs from the frames (3 – 4 l/min). After gastrulating, the hatchery is increasing frames (3 – 4 l/min). After gastrulating, the hatchery is increasing the volume of water higher (5 – 7 l/min). During embryogenesis, the volume of water higher (5 – 7 l/min). During embryogenesis, oxygen level in enclosures of incubation will be maintained at the oxygen level in enclosures of incubation will be maintained at the minimum values of 5 – 6 mg/l.minimum values of 5 – 6 mg/l.

• Control mould during incubation time will be achieved by bathing Control mould during incubation time will be achieved by bathing eggs with formalin solution for 15 minutes. The first treatment will eggs with formalin solution for 15 minutes. The first treatment will be achieved in 24 hours from fertilization, and following at be achieved in 24 hours from fertilization, and following at intervals of 12 hours until the appearance of ocular vesicles.intervals of 12 hours until the appearance of ocular vesicles.

• After hatch, frames out of hatchery, and larvae are kept in After hatch, frames out of hatchery, and larvae are kept in hatcheries until resorption of yolk. hatcheries until resorption of yolk.