TECHNOLOGY FOR ARTIFICIAL SPAWNING OFTECHNOLOGY FOR ARTIFICIAL SPAWNING OFTINCA TINCATINCA TINCA SPECIES – TENCH SPECIES – TENCH

TECHNOLOGY DISPLAYTECHNOLOGY DISPLAYObjectObject

• The elaborated technology is after The elaborated technology is after controlled spawning of controlled spawning of Tinca tincaTinca tinca – tench, – tench, towards redressing its natural populations towards redressing its natural populations and inserting it on aquaculture.and inserting it on aquaculture.Area of implementationArea of implementation

• Implicit costumers of spawning technology Implicit costumers of spawning technology are economical agents that have the main are economical agents that have the main activity fishing and aquaculture. activity fishing and aquaculture.

Technological system for artificial spawning of Technological system for artificial spawning of Tinca Tinca tincatinca – tench – tench

Technological system will be apportion depending on Technological system will be apportion depending on production capacity agreed by costumer, and will ensure by production capacity agreed by costumer, and will ensure by its capacity the spawning of minimum 10 families, in order its capacity the spawning of minimum 10 families, in order to insure maintenance and conservation of genetic to insure maintenance and conservation of genetic biodiversity of species.biodiversity of species.Correlate with the capacity for incubation, technological Correlate with the capacity for incubation, technological system will be framed by an ensemble of earthen ponds: system will be framed by an ensemble of earthen ponds: ponds for standing-wintering, ponds for pre-maturation, ponds for standing-wintering, ponds for pre-maturation, modules for standing and maturation of breeders, modules modules for standing and maturation of breeders, modules for incubation of embrionated eggs and modules for for incubation of embrionated eggs and modules for standing and growing larvae having the same technical standing and growing larvae having the same technical parameters as like as for wells. parameters as like as for wells.

• DESCRIPTION OF TECHNOLOGYDESCRIPTION OF TECHNOLOGY• The technology for artificial breeding and rearing of The technology for artificial breeding and rearing of Tinca Tinca

tincatinca larvae imply the passing through of following phases: larvae imply the passing through of following phases:• Assurance of breeders stock;Assurance of breeders stock;• Evaluation of phenotypic characters and sex determination;Evaluation of phenotypic characters and sex determination;• Standing, pre-maturation of breeders;Standing, pre-maturation of breeders;• Maturation of breeders;Maturation of breeders;• Induction of sexual cells maturation;Induction of sexual cells maturation;• Gathering sexual products;Gathering sexual products;• Fecundation;Fecundation;• Incubation of sexual products in special installed Incubation of sexual products in special installed

enclosures;enclosures;• Sacking and transportation of larvae;Sacking and transportation of larvae;• Rearing larvae up to 45 days. Rearing larvae up to 45 days.

• Assurance of breeders stock. Assurance of breeders stock. Tench breeders used in artificial Tench breeders used in artificial spawning come from stocks spawning come from stocks reared in farms especially for reared in farms especially for this goal or captured from this goal or captured from natural environment. In autumn, natural environment. In autumn, breeders are catch from rearing breeders are catch from rearing ponds and populated on ponds and populated on wintering ponds. Most times, wintering ponds. Most times, tench breeders are wintering tench breeders are wintering together with other cyprinids. For together with other cyprinids. For establishment of breeders stock establishment of breeders stock are chosen fish with age of 3 – 6 are chosen fish with age of 3 – 6 years and weight of 0.8 – 2.0 kg. years and weight of 0.8 – 2.0 kg.

• Evaluation of phenotypic characters and sex Evaluation of phenotypic characters and sex determinationdetermination

• Tench breeders are catch from wintering ponds and separated Tench breeders are catch from wintering ponds and separated depending on sex when water temperature attains 15 – 18 0C. depending on sex when water temperature attains 15 – 18 0C. Separation on sexes is accomplish easily, breeders exhibiting a Separation on sexes is accomplish easily, breeders exhibiting a pronounced sex dimorphism: male display an acute development pronounced sex dimorphism: male display an acute development of pelvic belt and of fins from this level, with bowing and bodying of pelvic belt and of fins from this level, with bowing and bodying up on a part of fins, and also males are bigger than females.up on a part of fins, and also males are bigger than females.

• For artificial spawning are used breeders having average body For artificial spawning are used breeders having average body weight between 800 – 1500 g/ex on females and between 1500 – weight between 800 – 1500 g/ex on females and between 1500 – 2000 g/ex on males.2000 g/ex on males.

• Breeders are hold in maturation ponds up on the moment when Breeders are hold in maturation ponds up on the moment when water temperature attain and remain around the value of 22 – 24 water temperature attain and remain around the value of 22 – 24 0C and don’t fell under 19 – 20 0C in the night. 0C and don’t fell under 19 – 20 0C in the night.

• Induction of sexual cells maturation Induction of sexual cells maturation • When water temperature is maintain around 22 0C, breeders, When water temperature is maintain around 22 0C, breeders,

mails and females are catch from maturation ponds and mails and females are catch from maturation ponds and stock in standing modules from incubation station.stock in standing modules from incubation station.

• Hormonal treatment goes through after 24 hours from Hormonal treatment goes through after 24 hours from stocking of breeders in the station for incubation. For stocking of breeders in the station for incubation. For induction of sexual cells maturation on tench, it is used carp induction of sexual cells maturation on tench, it is used carp pituitary. The total dose is of 10 mg/kg of body weight on pituitary. The total dose is of 10 mg/kg of body weight on females and 6 mg/kg of body weight on males.females and 6 mg/kg of body weight on males.

• Males are stimulated with a single dose of 6 mg/kg body Males are stimulated with a single dose of 6 mg/kg body weight.weight.

• Hormonal induction of females is made in two steps:Hormonal induction of females is made in two steps:• Step I – 3 – 4 mg/kg of female body weight;Step I – 3 – 4 mg/kg of female body weight;• Step II – 6 – 7 mg/kg of female body weight.Step II – 6 – 7 mg/kg of female body weight.• Injection is applied within the peritoneum. On temperatures Injection is applied within the peritoneum. On temperatures

of 23 – 25 0C, breeders are injected in the evening time, of 23 – 25 0C, breeders are injected in the evening time, dealing the first dose on females and entirely amount of dealing the first dose on females and entirely amount of hormone on males. The second dose on females is deal at an hormone on males. The second dose on females is deal at an interval of 8 – 10 hours. interval of 8 – 10 hours.

• Gathering eggs and artificial fertilization.Gathering eggs and artificial fertilization.• Gathering eggs is made by gently palpation of abdomen.Gathering eggs is made by gently palpation of abdomen.• Females release the eggs in one or more portions. From Females release the eggs in one or more portions. From

one female are gathering between 50 and 150 g of eggs. one female are gathering between 50 and 150 g of eggs. After gathering eggs, one gram of eggs are weight and then After gathering eggs, one gram of eggs are weight and then counter to determine absolutely fecundity (number of counter to determine absolutely fecundity (number of eggs / female) and relative fecundity (number of eggs / kg eggs / female) and relative fecundity (number of eggs / kg of female). One gram coincides with about 1400 eggs.of female). One gram coincides with about 1400 eggs.

• The same proceed with males; sperm is gathered in a The same proceed with males; sperm is gathered in a crystallizer by abdominal palpation or by using a syringe crystallizer by abdominal palpation or by using a syringe with tygon tube of 5-6 cm long. The tube is placed slowly in with tygon tube of 5-6 cm long. The tube is placed slowly in the urogenital outlet. At the exemplars whereat the the urogenital outlet. At the exemplars whereat the permeation is complete, sperm start to flow on syringe permeation is complete, sperm start to flow on syringe when primer is move back.when primer is move back.

• Volumetrically, the average quantity of gathered sperm is Volumetrically, the average quantity of gathered sperm is of 2.0 – 2.5 ml/kg of body weight. of 2.0 – 2.5 ml/kg of body weight.

• Artificial fecundationArtificial fecundation• Eggs gained from each Eggs gained from each

female are fertilize with a female are fertilize with a mixture of sperm from mixture of sperm from more males. For more males. For fertilization of 100 g of fertilization of 100 g of eggs are required 2 ml of eggs are required 2 ml of sperm. Fertilization is sperm. Fertilization is made by dry method. made by dry method. Sperm is dispersing on Sperm is dispersing on eggs, after that, the eggs, after that, the mixture is homogenized for mixture is homogenized for about 2 minutes. The about 2 minutes. The fertilized eggs are spread fertilized eggs are spread on frames and after on frames and after another 5 minutes, another 5 minutes, fertilized eggs are bringing fertilized eggs are bringing in Nucet hatcheries for in Nucet hatcheries for incubation. incubation.

• Incubation of sexual Incubation of sexual productsproducts

• Incubation of eggs will start Incubation of eggs will start with introduction and attach with introduction and attach of frames in the Nucet of frames in the Nucet hatcheries. Incubation lasts 2 hatcheries. Incubation lasts 2 – 3 days at the temperature of – 3 days at the temperature of 23 – 25 0C.23 – 25 0C.

• For tench, optimal For tench, optimal temperature for hatch is 23 – temperature for hatch is 23 – 25 0C.25 0C.

• During embryogenesis the During embryogenesis the flow of water supply for flow of water supply for incubation enclosures will be incubation enclosures will be correlated with physiological correlated with physiological necessities of embryo in its necessities of embryo in its different development phases. different development phases.

• Sampling and standing of larvaeSampling and standing of larvae• Sampling of hatched larvae is made continuously Sampling of hatched larvae is made continuously

on cushion of water, in individual tanks for on cushion of water, in individual tanks for gathering. Gathering tank is fitted with a nytal gathering. Gathering tank is fitted with a nytal cage having mesh size of 0.2 mm to constrict the cage having mesh size of 0.2 mm to constrict the larvae.larvae.

• The constricted larvae are sample with a The constricted larvae are sample with a standard measure and placed in other clean standard measure and placed in other clean hatcheries, where are hold up on the resorption of hatcheries, where are hold up on the resorption of vitelline bag, about 5 days at 24 – 25 0C.vitelline bag, about 5 days at 24 – 25 0C.

• Stocking density will be of 20 – 25.000 Stocking density will be of 20 – 25.000 ex/incubator. Water flow in tanks for standing of ex/incubator. Water flow in tanks for standing of larvae will be adjusted to 5 l/min. larvae will be adjusted to 5 l/min.

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

• Stoking rateStoking rate• Larvae achieved from each female are stoked independently on Larvae achieved from each female are stoked independently on

rearing enclosures.rearing enclosures.• Stoking rate is 10.000 ex/m3 and is determined taking into Stoking rate is 10.000 ex/m3 and is determined taking into

account technological losses for rearing phase which in general account technological losses for rearing phase which in general are estimated on 30 %.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.

• Technological water from enclosures will be assessing physic-Technological water from enclosures will be assessing physic-chemically by determination of temperature, pH and oxygen.chemically by determination of temperature, pH and oxygen.

• The flow of water supply in enclosures for pre-maturation is set at The flow of water supply in enclosures for pre-maturation is set at 5 – 7 l/min. 5 – 7 l/min.

• FeedingFeeding

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

• Feeding with natural food is achieved with very small zooplankton. The diet is Feeding with natural food is achieved with very small zooplankton. The diet is supply with blended yolk of egg.supply with blended yolk of egg.

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

• first 5 days: 85 % zooplankton, 15 % forage;first 5 days: 85 % zooplankton, 15 % forage;

• next 5 days: 60 % zooplankton, 40 % forage;next 5 days: 60 % zooplankton, 40 % forage;

• next 5 days: 50 % zooplankton, 50 % forage;next 5 days: 50 % zooplankton, 50 % forage;

• next 5 days: 10 % zooplankton, 90 % forage.next 5 days: 10 % zooplankton, 90 % forage.

• After that feeding will be assure only by forage.After that feeding will be assure only by forage.

• With the passage exclusively on forage, daily ration will be determined With the passage exclusively on forage, daily ration will be determined depending on consumption, percentage ranging from 4 to 20 % of batch depending on consumption, percentage ranging from 4 to 20 % of batch weight.weight.

• For tench rearing shall be used carp feeds with a content of crude protein For tench rearing shall be used carp feeds with a content of crude protein ranging from 35 to 45 % and granulation of 0.1 – 0.2 mm. Feeds shell be ranging from 35 to 45 % and granulation of 0.1 – 0.2 mm. Feeds shell be delivered in 8 – 10 meals per day.delivered in 8 – 10 meals per day.

• The growth gain that has to be achieved after 30 days, up to outlining of The growth gain that has to be achieved after 30 days, up to outlining of adult-like phenotypic characters, is 300 – 500 mg/ex. adult-like phenotypic characters, is 300 – 500 mg/ex.

• Terms of maintenance on rearing timeTerms of maintenance on rearing time• On the rearing enclosures must be keep a severe sanitation. The On the rearing enclosures must be keep a severe sanitation. The

sanitation will be achieved before every feeding and will consist of sanitation will be achieved before every feeding and will consist of removing excrements and any offal of feeds from the last meal. At removing excrements and any offal of feeds from the last meal. At least once every 24 hours to clean the walls of rearing enclosure least once every 24 hours to clean the walls of rearing enclosure through rubbing them with a sponge flooded in a solution of through rubbing them with a sponge flooded in a solution of potassium permanganate with a concentration of 23 mg/l. Also potassium permanganate with a concentration of 23 mg/l. Also can be used methylene blue on a concentration of 1 %. can be used methylene blue on a concentration of 1 %.