Home Crop Monitoring Species of Female Fish and their Method of Reproduction

Species of Female Fish and their Method of Reproduction

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An all feminine fish (freshwater) species known as the Amazon molly that inhabits rivers and creeks alongside the Texas-Mexico border resides proof that sexual copy could also be vastly over-rated based on WASHINGTON (Reuters).

In the meantime, Female fish can breed a brand new species in the event that they aren’t picky about who’s Mr. Proper. Fish will mate with a species outdoors their personal if the male’s coloring is enticing sufficient or if the feminine can’t see him correctly, based on new analysis. Such ‘mistakes’ in mate alternative can result in the evolution of new species, a world workforce of scientists discovered after they analyzed the DNA of greater than 400 cichlid fish.

In lots of animal species, females are anticipated to decide on mates based on standards which are related to their personal health. Direct advantages obtained from adaptive mate alternative embrace materials assets offered by the male, in addition to brood care and safety, which might improve the feminine’s current and lifetime fecundity. Oblique advantages for the feminine are derived from excessive health of her offspring, to which the male contributes genes and parental funding.

Commerce-offs between direct and oblique advantages have been recognized in a number of species, however constructive correlations are additionally potential, for instance, if the genetic high quality of a male additionally advantages a feminine mate straight. If males require sure assets reminiscent of territories or nest websites for mating, male–male competitors can slim the pool of candidate mates to aggressive people and thus can facilitate feminine alternative.

One prerequisite of intensive fish tradition expertise is to have wholesome fish seed within the required quantity accessible. This may be realized solely with preliminary propagation planning. In addition to pure and semi-artificial propagation, synthetic propagation carried out in a well-equipped hatchery is the up-to-date manner by which the mandatory amount of fry may be produced.

1.1 Tradition and Administration of Brood Inventory

A primary precondition of fish propagation is to have sexually mature male and feminine fish producing milt and eggs. Breeders of fish species which can’t be cultured or stored domestically, are collected earlier than spawning from rivers or lakes, their milt or eggs are stripped and then they’re launched once more. These species are sturgeons (mullets) mugils (Mugilidae), and salmonids (Salmonidae).

The brood inventory of cultured fish species are sorted out with aimed choice and cultured in fish ponds as much as sexual maturity. The males and females of breeders are cultured in the identical fish pond whereas they’re younger. Then, when sexually mature they’re chosen and cultured in separate fish ponds.

1.2 Environmental Situations for Culturing Breeders

When culturing breeders, the next environmental situations must be ensured contemplating the particular calls for of the respective species: – appropriate water and pond
– temperature
– oxygen
– feed gentle/photoperiod

Throughout culturing of breeders, the water high quality ought to meet the identical requirement as throughout routine fish tradition.

For species with choice for nonetheless water (e.g. cyprinids, catfish, tilapia) earthen or concrete-walled fish ponds must be constructed. For rheophyl species (e.g. trout) flow-through methods, canals, or tanks with circulating water must be offered.

The temperature, as an environmental issue, has an essential function in fish tradition. Fish are a polikilotherm animal, which signifies that their physique temperature follows the encompassing temperature, however in case of elevated muscular work and metabolism it may be considerably greater.

Fish may be heat water or chilly water species

Chilly water fish are salmonids and trout. Their optimum temperature vary is 10-16°C and their oxygen demand is excessive.

Warmwater fish are the cyprinids like widespread carp, Chinese language carp, Indian carps and from different households the tilapia, milkfish, mullet and the American catfish. Their optimum temperature vary is 18-26°C.

There are some species “in-between”, they reproduce in chilly water, however later can reside in heat waters too. Such are pike and pike-perch. The event may be vastly influenced by water temperature. Feeding at low temperature may be regular, however the conversion of the feed, and consequently the expansion, particularly sexual maturation may be significantly slower. The period of sexual maturation additionally relies upon, first of all, on the environmental temperature, with most fish species, thus there’s a attribute whole temperature worth for every species which is critical for gametogenesis.

Within the case of carp, from hatching to the primary copy, 10-12 000 diploma days of warmth is critical. This amount of warmth below a tropical local weather is ensured in l-l.5 years whereas in Center Europe in 3.5-4 years.

1 600-2 000 diploma days is critical within the correct temperature vary for the oogenesis of matured carps between two propagations. If the temperature is decrease than that, contemplating the times with temperature greater than 17°C solely, it’s 2 500-2 700 diploma days. The minimal temperature which is critical for propagation of carps is 17°C, under this worth the gametogenesis could be very gradual.

Optimum oxygen content material of water is essential particularly in energetic cytogenetic processes. Growth of gametes and full conversion of feed are all oxygen consuming processes. In case of oxygen deficiency the gematogenesis slows down, growth is inhibited and whether it is extended the resorption of gametes begins. Due to this fact, the correct oxygen provide is an important level of brood inventory tradition.

Feeding of breeders, particularly within the nutriment accumulating section of oogenesis requires feed of particular composition. Amino acids, carbohydrates, fat, nutritional vitamins, and minerals can be found for the fish by way of pure feeding. However at excessive stocking density below managed culturing situations these should be offered via synthetic feed. It’s also essential that the breeders can get the sort of feed attribute of their species, i.e. herbivorous fish ought to get nutriment of plant origin, and carnivorous ought to get nutriment of animal origin.

Mild/photoperiod has a major function within the reproductive processes of a number of fish species.

Stress components, and the sensitivity of the aesthetic breeders to those components additionally must be stored in thoughts. Dealing with, transportation, enclosure which all differ from their regular lives, are stress inducing components, and could have an effect on their situation.

This will likely hinder the final section of maturation and ovulation. Due to this fact, situations must be established for the breeders the place all these stress components may be minimized. – Stocking density should be optimum, thus making certain a provide of pure meals; – Water provide, stream fee, temperature and oxygen content material ought to meet the necessities of the fish; – Breeders throughout spawning are stored in smaller measurement fish ponds or concrete tanks.

Their filling or draining must be environment friendly for the reason that fish should be caught fairly often; – Breeders may be transported in tanks solely, sustaining the correct oxygen content material by spraying liquid oxygen; – case of timid fish (e.g. Chinese language carps) sedatives may be added to the water; – When dealing with is critical, the seine may be utilized.

Handbook transportation of fish wants ability, so well-trained fishermen ought to do it. If the breeder with eggs is dropped it might lose the eggs, the ovary inflames and typically the fish dies.

Learn Additionally: Find out how to Establish and Deal with Illnesses in your Fish Farm

The Synthetic Propagation of Cultivated Fish Species

2.1 Frequent carp

Species: Frequent carp (Cyprinus carpio L.)
Origin: China, South Asia, Europe
Pure habitat: Rivers, lakes, fish ponds
Feeding and diet: Zooplankton, water bugs and their larvae, backside inhabiting organisms, grains and granular and pellet meals

Weight, at age intervals: (Europe solely)

12 months Grams
1 20 – 100
2 200 – 500
3 800 – 2 500
4 3 000 – 4 000
5 4 000 – 5 000

2.1.1 Reproduction

In a pure atmosphere, the fish spawn in teams, in lakes and gradual transferring rivers, at a water temperature of 18 to 22°C. The egg attaches itself to vegetation and hatches inside three days. In intensive cultivation they’re spawned in small ponds. Strategies of fashionable synthetic propagation had been developed by Woynárovich (Hungary).

2.1.2 Financial characterization

– Fast progress
– Excessive diploma of fecundity
– Excessive meat high quality, although containing intermuscular bone
– Very appropriate to warmwater polyculture Good sport fish.

2.1.3 Synthetic propagation

Rearing and holding of the brood inventory: the younger brood inventory is chosen from the offspring of mother and father of identified high quality.

The choice standards are: – Fast progress
– Good viability
– Excessive meals conversion fee
– Low fats content material
– Resistance to illness.

The brood inventory is reared in particular person ponds, segregating male and feminine. The stocking density of the rearing ponds is 500 to 1 000 adults per hectare.

Feed is a synthetic pellet, containing 20 to 25 p.c of protein, of which 15 to 18 p.c is animal protein; fat 3 to 4 p.c; vitamin premix 2 p.c; mineral pre-mix 1 p.c. Nutritional vitamins A and E are important. For 2 months previous to propagation the each day feed ought to include 5 to 10 p.c of uncooked floor meat or exhausting boiled eggs. Feed amount is 2 to five p.c of physique weight, per day.

Sexually mature fish measure 35 to 70 cm and weigh 2 500 to 10 000 g.

The fish obtain sexual maturity in Europe: feminine 3 to 4 years, male 2 to three years. In tropical climates: feminine 1 to 2 years, male 1 12 months.

The feminine has a big stomach. The male, if calmly squeezed across the stomach will emit white milt.

Dealing with of the spawners: – The spawners must be moved into the hatchery sooner or later previous to propagation; – The spawners must be transported in containers made of inorganic, non metallic supplies; – The male and feminine spawners ought to proceed to be segregated within the hatchery, in plastic or concrete tanks; – Area requirement is 0.5 to 1m2/grownup; – Tanks must be 5 to 10 m2, 1 to 1.2 m deep; – Water amount required is 4 to six litres, per fish, per minute; – Oxygen content material of the water must be 6 to eight mg/l; – Water temperature must be 20 to 22°C; – Previous to dealing with, the fish could also be tranquilized; – The tranquilizer really helpful is MS 222 (Sandoz), in a 1:10 000 dilution; – After 5 to 10 minutes within the above resolution, the fish must be moved into contemporary water of excessive oxygen content material, in any other case they are going to perish.

Hypophysation: – To induce ovulation within the feminine and milt manufacturing within the male, hormone of the carp’s pituitary gland is used; – The dosage used within the hypophysation of the feminine is 4 to 4.5 mg per kg of physique weight; – The dosage for the male is 3 mg per kg of physique weight; – The dried pituitary gland is pulverized and dissolved in a 0.65 p.c resolution of salt (NaCl); – 2 ml salt resolution per fish is used; – The hypophysation of the feminine must be achieved in two levels; – Ten p.c of the dosage is given 24 hours earlier than the removing of eggs; – 90 p.c of the dosage is given 12 to 14 hours previous to the removing of eggs, if the water temperature is 21 to 22°C (240-260 diploma hours); – The injection is finished with a effective needle, into the muscle of the again; – Previous to withdrawal of the needle, the locus of the injection is calmly massaged, with the intention to keep away from leakage of the answer injected; – Concurrent with the second injection, the opening of the oviduct is sewn as much as stop the loss of mature eggs in the course of the interval of ovulation; – The suture is finished with surgical implements; – The male is to be injected 24 hours previous to the specified time of milt discharge; – It’s crucial that the fish within the hatchery have completely quiet environment.

The removing of eggs and milt, fertilization – One hour previous to removing of the eggs, one or two males are positioned among the many females; – On the onset of ovulation, the male and feminine fish will swim alongside aspect each other, flapping forcefully; – One half hour ought to elapse to guarantee that the total amount of eggs may have indifferent itself from the partitions of the ovary; – After this time, the feminine fish are tranquilized; – The sutures are faraway from the opening of the oviduct; – The stomach of the fish must be wiped dry with a material, to stop wetting the eggs which is able to quickly lose their fertility if blended with water; – The eggs are launched into 2 litre plastic dishes; if needed, gentle strain could also be utilized to the stomach to make the roe stream out; – The milt is pressed out of the male with gentle strain into check tubes; – The eggs must be fertilized instantly upon their removing from the feminine; – Ten to twenty ml milt is used to at least one litre of eggs; – Every batch of eggs must be fertilized with milt from at least three males, for the reason that sperm of any male could sometimes be inactive; – The eggs and milt are completely blended (with out the addition of any water), so that every one eggs are reached by the milt; – The blending must be achieved with a plastic spoon; – Fertilization is promoted by the use of a fertilizing resolution; – The substances of the answer are: water, 1 litre
salt, 4 grams
urea, 3 grams (CO/NH2/2) – Temperature of the answer must be 20 to 22°C; – The fertilizing resolution has a two-fold impact, it prevents the adhesion of the eggs and it prompts the sperm; – 100 ml of the answer is added to 1 litre of roe and instantly blended with it; – The blending motion must be steady; – At two minute intervals, one other 100 ml of the answer is added to the combination; – After ten minutes, the fertilizing resolution is poured off; – Recent fertilizing resolution is added, 2 litre resolution to 1 litre of eggs; – The eggs, along with the fertilizing resolution, are then poured right into a plastic container of 15 to twenty litre capability; – The eggs will swell to 4 to five instances their unique quantity inside one hour; – For one hour, the fertilizing resolution must be exchanged at ten minute intervals, with the intention to proceed to dissolve and take away the adhesive of the eggs; – Mixing must be achieved intermittently and gently whether or not manually or mechanically; – After one hour of the above course of the eggs must be handled with a tannic acid resolution, with the intention to dissolve the adhesives coagulated in the course of the earlier remedy and nonetheless current on the floor of the eggs; – The tannic resolution consists of 1.5 gram tannin dissolved in 1 litre water; – Remedy with the tannic resolution is preceded by pouring off the fertilizing resolution; – One to 2 litres of tannic resolution is added to the eggs and instantly blended in; – After ten seconds, water is added to dilute the tannic resolution; – The answer is then instantly poured off; – The eggs ought to then be rinsed 3 or 4 instances with ample portions of water; – After rinsing the eggs are positioned in hatching jars.

Hatching: – Water temperature throughout hatching must be 20 to 22°C; – One litre of hatching jar quantity is required for every 20 000 eggs; – The amount of 20 000 swollen eggs is 200 ml; – The eggs are a dangerous course of, for the reason that segmentation of the ovum is already began and sturdy jolting will destroy it; – The eggs are positioned within the water-filled hatching jar with the help of a funnel, which is provided with a size of hose, to guarantee that they are going to exit from it below water; – Within the first ten hours, the hatching jar is to have a average stream of water: assuming a ten litre jar, the speed can be 0.8 to 1 l/min; – After ten hours, the stream must be elevated, for the reason that oxygen want of the ova is on the rise, to a fee of 1.5 to 2.5 l/min; – The eggs might be drifting loosely on the underside of the hatching jar; – 4 to 5 hours previous to hatching, the embryos’ want of oxygen is appreciable, due to this fact, the stream fee must be elevated to 2.5 to three l/min.; – On the second day of the hatching course of, the eggs must be handled with malachite inexperienced to stop the technology of fungus; – Malachite inexperienced is added to the water within the hatching jar in a amount to offer a 1:200 000 resolution; – Let the answer stand for five minutes; – After 5 minutes, the water stream is restored and the malachite resolution will thereby be slowly washed out; – Hatching of the larvae could also be anticipated on the third day; – After the primary few larvae have hatched, the method must be artificially accelerated; – That is completed by shutting off the stream of water for 10 minutes. The dearth of oxygen agitates the embryos, and because of their actions the shell will cut up; – After 10 minutes, the water stream is restored and hatching will begin on a big scale; – The hatched larvae are transferred, along with the water, into larvae containers.

Upkeep of the larvae: – The implements used within the upkeep of larvae could also be anybody of the next: 1. Cylindrical containers, conical on the decrease finish, of 50 to 150 litre capability, of glass, plastic or fibreglass, 2. Round stream raceways of concrete or plastic, 3. Cages made of nylon material (display screen). 1. Cylinders – Within the containers 2 000 larvae per litre of water may be maintained; – Water ought to enter on the backside and stream out on the high of the container; – The world of the overflow display screen must be 10 cm2/litre of capability; – The stream fee must be such that the larvae are stored in suspension however not washed onto the overflow display screen; – The display screen must be cleaned at intervals, as it will likely be stopped up with stays of shells; – The larvae are stored in these containers solely till their first consumption of feed (3 to 4 days), after which they’re transferred to rearing ponds; – The above course of is essentially the most up-to-date and most hygienic technique of holding the larvae. 2. Raceways – The raceways, of plastic or concrete, must be of 1 to 2 m3 capability, the depth being 60 to 80 cm; – Water enters the raceway via perforated tubes positioned vertically at two reverse sides, to guarantee a round stream; – The speed of stream must be such that it produces a relentless gradual movement of the water; – The overflow tube is positioned within the centre, vertically; – The overflow display screen, of nylon, ought to have 0.8 mm openings; – Floor space of the display screen must be 8 to 10 cm2/litre of stream; – The oxygen content material of the water is elevated by floor spraying; – The raceway must be stocked on the fee of 1 000 hatchlings per litre of water; – The benefit of this technique is that the larvae may be stored for a number of days past the primary feeding, if appropriate nourishment may be assured. 3. Cages – Measurement: 70×40×30 cm; – Body: aluminium or plastic tubing; – Screening: of nylon, 0.8 mm opening; – The cages are stored in plastic or concrete tanks; – An upward stream of water via the cages is required which retains the larvae in movement; – That is effected by laying tubing, perforated on the high, on the tank backside; – The underside of the cage must be cleaned the day after hatching to take away shells and unhatched larvae, which is able to begin to decompose thus inflicting oxygen deficiency; – The underside and sides of the cage must be cleaned with a brush from the skin at 6-hour intervals with the intention to guarantee free passage of water into the cage; – The speed of stream within the tanks must be 4 to five l/min/cage; – To extend the oxygen content material of the water, a effective floor spraying must be used.

Feeding and transportation of the brood: – The mouth and gills of the carp larva develop in 3 to 4 days; – The carp’s larval stage ends with the primary consumption of meals, at this level it turns into fry; – At this stage the yolk sac may have been largely absorbed; – At this level the hatchlings will rise to the floor of the water, fill the swimming bladders with air and start to swim horizontally; – Presently the primary feeding is given; – The feed is yolk of exhausting boiled egg (hen’s or duck’s egg) blended in a blender with water; – 100 ml water per one yolk is used; – One to 2 ml per 100 000 fish is given at 2-hour intervals; – As quickly because the hatchlings start to feed, they need to be transferred to ponds; – The 4-day outdated feeding fry are transported in plastic baggage containing water and oxygen; – In 20 litres water plus 30 litres oxygen, at 20°C water temperature, 100 000 brood could also be stored as much as 5 hours; at 15°C, 200 000 brood could also be stored as much as 5 hours; – If chilled for transport, the temperature of brood and water must be lowered step by step; – The plastic baggage, when crammed, must be as agency as properly crammed balloons; – The baggage should be properly tied, to stop escape of the oxygen; – To keep away from rupture, the luggage must be positioned in cardboard bins; – The 4-day outdated larva measure 6 to 7 mm in size.

Organic and technical knowledge: – The sexually mature fish measure 35 to 70 cm, and weigh 2 500 to 10 000 g; – The interval of propagation in Europe is Could via July; – Optimum water temperature is 20 to 22°C; – Optimum male to feminine intercourse ratio is 1:1; – 70 to 80 p.c of the females subjected to hypophysation could also be anticipated to provide eggs; – Amount of eggs per feminine will fluctuate from 200 000 to 1 500 000; – Amount of eggs by physique weight of feminine is 100 000 to 200 000/kg; – Amount of eggs by weight is 500 to 1 000 g dry; – Milt manufacturing is 10 to twenty ml per male; – Fertilization of 1 000 g of eggs requires 10 to fifteen ml milt; – Dry measurement of the egg is 1.0 to 1.5 mm diameter, within the swollen state 2.0 to 2.5 mm; – Rely of dry eggs per kg is 700 000 to 1 000 000; – Rely of swollen eggs per litre is 80 000 to 120 000; – Amount of eggs to be positioned in a ten litre hatching jar: 150 to 250 g dry, or 1.5 to 2.5 litre swollen eggs; – Fertility fee of the eggs is 80 to 95 p.c; – Time required for hatching within the hatching jar is 3.0 to three.5 days (60 to 70 diploma days); – Profitable hatching of 90 to 95 p.c of the fertile eggs could also be anticipated; – Time span of the larval stage is 3 to 4 days (60 to 70 diploma days); – Survival fee of the hatched larvae to the primary feeding is 90 to 95 p.c; – 1 kg of dry eggs will produce 600 000 to 800 000 four-day outdated brood: – Larva containers are stocked on the fee of 2 000 larvae/litre; – 4-day outdated fry measure 6 to 7 mm in size; – First feeding will happen inside 3 to 4 days of hatching; – Measurement of the fish feed must be 50 to 150 micron; – Space of the rearing pond is 500 to 10 000 m2; – Density of stocking must be 200 to 500 per m2; – Transportation of the four-day outdated fry: in 20 litres water plus 30 litres oxygen, at 20°C water temperature, 100 000 fry could also be stored as much as 5 hours; at 15°C 200 000 fry could also be stored as much as 5 hours.

2.2 Chinese language Herbivorous Fishes

Species:
Silver Carp (Hypophthalmichthys molitrix Val.)(SC)
Bighead Carp(Aristichthys nobilis)
Grass Carp (Ctenopharyngodon idella Val.) (GC)
Origin: Southeast Asia
Pure habitat: Giant rivers, heat water, lakes, fish ponds
Feeding and diet:
Silver Carp (SC) phytoplankton food regimen
Bighead Carp (BC) zooplankton food regimen
Grass Carp (GC) aquatic macrophyte food regimen

Measurement at ages in grams

Years SC BC GC
1 10 – 15 15 – 30 10 – 20
2 100 – 200 150 – 300 150 – 250
3 500 – 800 800 – 1 500 800 – 1 500
4 1 500 – 2 000 3 000 – 4 000 2 500 – 3 000
5 3 000 – 4 000 5 000 – 6 000 4 500 – 5 000
6 4 500 – 5 000 7 000 – 8 000 6 000 – 7 000

2.2.1 Reproduction

– In slowly flowing heat rivers they spawn in teams;
– In cultured situations, spawning happens solely artificially;
– Spawning temperature, 22-26°C;
– The eggs are pelagic.

2.2.2 Financial characterization

– Good high quality of meat;
– Good sport fishing (GC)
– In polyculture they make the most of the first and secondary manufacturing of the water straight;
– GC controls the macrophytes in lakes and channels.

2.2.3 Synthetic propagation

– Maintain the inventory materials in a particular pond; – Stocking fee per hectare (ha)

SC 50
BC 50
GC 50
Cc 100 (widespread carp or any type of backside cultivator and artificially fed fish)

Age by spawning in years

Female Male
SC 5-6 4-5
BC 7-8 6-7
GC 6-7 4-5

2.2.4 Sexual differentiation

The primary exhausting rays of the pectoral fins of the male are sharp whereas these of the feminine are clean.

2.2.5 Dealing with of spawners

– The next tranquilizers have been used efficiently to stop energetic transferring and leaping.

MS 222 (Sandoz)x 1 to 10 000 – 1 to 40 000
Quinaldinexx 1 to 100 000

x MS 222 may be obtained from: Sandoz Ltd. CH-4002 Basle, Switzerland
xx Quinaldine (2-methyl-quinoline) in pharmacy. – After 5 to 10 minutes of relaxation, put the fish into the contemporary water to be refreshed;
– Transfer the spawning fish rigorously by utilizing plastic stretchers.

2.2.6 Hypophysation

– For the induced ovulation of the eggs and milt we use the pituitary gland of carp dissolved in 0.65% NaCl resolution; – Calculate the dose of dry hypophysis on the premise of a most define of the physique, by females, circumference:

under 50 cm 4 mg/kg
50 – 60 cm 4.5 mg/kg
over 60 cm 5 mg/kg

– The dose of the males is 2 mg/kg.

Time of injection – Female dosage – the primary dose, which is 10% of the overall, is injected 24 hours earlier than spawning. The second dose, which is 90% of the overall, is injected 9 to 11 hours earlier than spawning or 200-220 diploma hours. – Male dosage – the overall doses are given 24 hours earlier than spawning.

2.2.7 Maintaining injected fish within the hatchery

– The injected females and males are collectively in a plastic or concrete raceway;
– The scale of raceway: 20-50 sq. metres, 1 to 1.5 metres deep;
– Mandatory floor: 1.5 sq. metres per fish;
– Working water: 4 to six litres per minute per fish;
– Water temperature: 22 to 26°C;
– Ovulation interval: 9 to 11 hours after the second injection, or 200 to 220 diploma hours.

Essential: Room should be stored quiet.

2.2.8 Procurement of eggs and milt

– At spawning time, we narcotize the fish;
– Acquire the eggs in a plastic dish and the milt in a glass check tube.

2.2.9 Fertilization of eggs

Essential: After taking the eggs, fertilize instantly. – 1 litre of eggs per 10 ml of milt;
– Combine the eggs and milt collectively rigorously in dry situations (not with water);
– Combine constantly, however rigorously, 1 litre eggs and milt combination and 0.1 litre pure pond water;
– Two minutes later, add a further 0.1 litre water and combine;
– After 5 minutes rinse the eggs a number of instances with water;
– Ten minutes later, after fertilization, put the eggs right into a spawning jar.

2.2.10 The ripening, attending and hatching of the eggs

– For a 1-litre spawning jar, use 5 mls dry eggs; – The measurement of hatching glasses are 8 to 10 litres or 50 litres, clear plastic or glass; – The water requirement of 10-litre measurement spawning jars in the course of the first 10 hours is 0.2 to 0.3 litres per minute, after 10 hours – 0.5 to 0.8 litres per minute, and in the course of the hatching interval – 1 to 1.2 litres per minute; – The swelling of the eggs might be full after 1 to 2 hours; – The diameter of the swelled eggs is 4 to five mm; – If the eggs hatch out earlier than the anticipated time, and the fry are untimely as a result of of micro organism, we use formalin within the water, 1 to five 000 or 1 to 10 000 each 5 hours; – Hatching happens 24 to 32 hours after fertilization if the water temperature is 22 to 26°C.

2.2.11 Maintaining the larvae

– After hatching, the larvae go away the spawning jars and are collected; – The collectors used mostly are giant Zuger glasses (50 – 200 litres glass or plastic) or raceways 1-2 cubic metres in measurement, plastic or concrete – The display screen of the overflow ought to have a 0.8 – 0.9 mm mesh nylon filter; – Safety filter floor – 10 sq. cm per litre; – Stocking density within the larva rearing tanks must be 1 000 per litre; – Maintain constantly operating water within the rearing tanks; – Maintain larvae within the tanks for 4 to 5 days; – Throughout this time, the mouth and gill are developed and the larva fills up swimming bladder with air; – At this stage, the larvae may be fed boiled egg yolk suspended within the water Use a dose of 1 ml per 100 000 fish per two-hour interval; – If the larvae are in a position to eat, put them within the rearing pond.

2.2.12 Organic and technological knowledge spawning ages in years

Female Male
SC 5-6 4-5
BC 7-8 6-7
GC 6-7 4-5

– The scale of mature fish

cm. kg.
SC 40 – 60 3 – 4
BC 70 – 80 8 – 10
GC 60 – 70 5 – 6

– The copy season is Could to July when temperatures are 20 – 26°C;
– The intercourse ratio by propagation is feminine:male = 1: 1;
– Anticipated share of spawners which produce eggs after hypophysation is 70-90%;
– Quantity of eggs produced is 60 000 – 80 000 per kg of physique weight;
– Weight and quantity of eggs obtained from one feminine:

Weight in grams No. of eggs
SC 700 – 800 200 000 – 1 500 000
BC 800 – 1 300 200 000 – 1 200 000
GC 500 – 1 000 200 000 – 1 500 000

– Amount of sperm obtained from one male after hypophysation is 10 – 20 ml;
– The required ratio of milt to eggs is 10 ml milt per 1 000 g dry eggs;
– The diameter of eggs, mm

Dry Swollen
SC 0.7 – 1.0 3.7 – 5.3
BC 1.0 – 1.1 3.7 – 5.3
GC 0.9 – 1.2 3.7 – 5.3

– The quantity of dry eggs per litre is:

SC 900 000 – 1 100 000
BC 600 000 – 800 000
GC 800 000 – 900 000

– The quantity of swelled eggs per litre is:

SC 18 000 – 22 000
BC 12 000 – 16 000
GC 16 000 – 18 000

– Stocking density of spawning jars:

dry eggs 5 g/l
swollen eggs 0.25 g/l

– Fecundity of eggs: 75 – 95 %;
– Growth of eggs in spawning jar: 24-36 hours at 20-25°C;
– Hatching ratio of the fertilized eggs: 80-90%;
– The time span from hatching to first feeding of larvae: 3-4 days, 60-70 diploma days;
– Anticipated manufacturing for 4 days: 400 000 – 600 000 larvae from 1 kg dry eggs;
– The larvae start to eat once they attain a measurement of 6-7 mm;
– The measurement of first meals: 50-300 m;
– The time of first feeding after hatching: 3-4 days.

Associated: Tendencies in Crop Manufacturing Nationally and Globally

Male fish and Female fish
Male fish and Female fish

2.3 European Catfish

Species: European catfish (Sheatfish, Silurus glanis L.)
Origin: a usually European species
Pure habitat: Rivers, lakes, synthetic ponds
Feeding: carnivorous predator, may also eat carrion. Effectively suited to synthetic feeds

Weight, at age intervals:

12 months Grams
1 20 – 100
2 200 – 400
3 500 – 2 000
4 3 000 – 4 000
5 5 000 – 6 000
6 7 000 – 10 000

2.3.1 Reproduction

In pure circumstances the fish uncover the roots of aquatic vegetation, depositing the eggs amongst these roots. The eggs cohere right into a lump. After hatching, the larvae stay hidden right here. Six to eight days later, the fry emerge swimming and depart in search of meals.

In rearing ponds, they spawn on “artificial nests”, that are then eliminated to the hatchery. Could also be artificially propagated in hatcheries.

Required temperature for replica: 22 – 24°C.

2.3.2 Financial characterization

– Fast progress;
– Good high quality meat, with no intramuscular bone;
– Eats undesirable small fish;
– Good sport fish;
– Effectively suited to polyculture.

2.3.3 Synthetic propagation

– The brood inventory is stored in particular person ponds of their personal; – Area requirement is 1-2 m2/fish; – The fish is small, inhabiting the identical ponds; – The ponds should at all times include prey amounting to twenty to 30 p.c of the brood inventory in weight; – The brood inventory should be disinfected at six-month intervals as safety in opposition to parasites; – Sexually mature fish weigh 3 000 to fifteen 000 g; – Age at which sexual maturity is achieved: male 3 to 4 years, feminine 4 to five years; – One month earlier than propagation, the males and females must be separated and positioned in segregated ponds.

Distinguishing sexual traits: – The frontal portion of the pinnacle, concerning the mouth, is angular within the male, whereas rotund within the feminine;
– The genital papilla of the male is pointed, that of the feminine blunt and rounded.

Hypophysation: – As a response to the hormone, the catfish turn out to be extraordinarily irritable and will chew each other; to stop this, the mouth is sewn shut with a single sew, utilizing a sturdy, straight needle; – To induce ovulation of each egg and milt, hypophysation (with carp’s pituitaty gland) is used; – The dry, pulverized pituitary gland is dissolved in a 0.65 p.c saline resolution; – 2 ml/fish is used of the answer; – The hypophysis dosage required to induce ovulation is 4 to five mg/kg of physique weight for the feminine, 3 to 4 mg/kg of physique weight for the male; – Hypophysation must be achieved 24 hours previous to the removing of eggs/milt, at water temperature of 22 to 24°C (200-220 diploma hours); – After the injection, the brood inventory is stored in tanks within the hatchery, segregating males and females; – Fixed water stream and excessive oxygen content material, with the addition of air or oxygen, must be maintained within the tanks; – The tanks must be lined, for the reason that fish might be calmer at nighttime.

The removing of eggs and milt, fertilization: – From hypophysation to ovulation 220 diploma hours are required. Hourly temperature readings are taken within the tank housing the females, when 220 diploma hours is achieved, ovulation may be anticipated; – At this level each females and males are tranquilized; – The tranquilizer used is MS222, in a 1:10 000 focus; – The stomach of the feminine must be wiped dry utilizing a material to keep away from wetting the eggs; – Utilizing slight strain, the eggs are simply expressed and collected into plastic dishes of 1 to 2 litre capability; – If hatching jars of 10 litre capability are for use, 100 to 200 g of eggs must be collected into every dish, this being the amount to be positioned into the hatching jars; – 1 000 g of eggs (dry) require 10 to twenty ml of milt; – The eggs and milt are blended dry, then 20 to 30 ml of water is added; – The eggs and water resolution must be blended for 5 minutes within the dish earlier than placement into the hatching jars; – The eggs must be poured into the hatching jar whereas the jar is being rotated in such a style that the eggs floating within the resolution will deposit themselves in a reasonably uniform layer onto the inside floor of the jar and adhere thereto; – No multiple or two layers must be thus adhered, since deeper layering would trigger oxygen deprivation, ensuing within the demise of giant portions of eggs; – The eggs are 4 to five mm in diameter; – After placement of the eggs, the jars are placed on their racks, and water stream is established.

Hatching: – An uninterrupted water stream, of 1.5 to 2 litres/minute must be maintained within the hatching jars; – To stop the technology of fungus, the eggs are rinsed a few times each day with a 1:200 000 resolution of malachite inexperienced for 5 minutes; – Hatching could also be anticipated on the third day, if the water temperature is 22 to 24°C, 50 to 60 diploma days being required for the whole growth of the embryo; – The hatched larvae must be drained from the hatching jars with the help of a rubber tube and positioned into holding cages; – The larvae are yellow in color and are 8 to 9 mm in size.

Maintaining of the larvae: – The larvae are stored in cages of 0.8 to 0.9 mm nylon mesh, the scale of the cage being 70 × 40 × 30 cm; – The cages must be stocked on the fee of 300 to 400 larvae per litre; – The cages are positioned in tanks with flowing water; – Water temperature must be 22 to 24°C; – The larvae will start feeding on the fourth day; – The primary pigmentation spots seem on them about this time; – The primary feed given the larvae is zooplankton or finely chopped tubifex (mud inhabiting worms).

Organic and technical knowledge: – Age at sexual maturity: male – 3 to 4 years, feminine – 4 to five years; – Sexually mature fish measure 50 to 70 cm; – The spawning season is Could to June; – Water temperature required for spawning: 22 to 24°C; – Optimum male to feminine intercourse ratio is 2:1 for synthetic propagation; – The effectiveness of hypophysation of the feminine is 80 to 90 p.c; – Amount of eggs per feminine: 40 000 to 120 000 or 200 to 600 g dry weight; – Amount of eggs by physique weight of the feminine: 20 000-30 000/kg; – Amount of milt per male, with hypophysation: 5 to 10 ml; – Fertilization of 1 000 g of eggs requires 10 to twenty ml of milt; – Dry measurement of eggs: 1.5 to 2.0 mm, swollen: 4 to five mm; – Rely of dry eggs per kg: 180 000 to 220 000; – Rely of swollen eggs per litre: 30 000 to 50 000; – Stocking density of hatching jars: dry eggs, 20 mg/l, swollen eggs, 100 ml/l; – Fertility fee of the eggs is 70 to 90 p.c; – Time required for hatching in hatching jars: 2.5 to three days (50 to 60 diploma days); – Hatching ratio of fertile eggs is 70 to 80 p.c; – Time span of the larval stage is 4 to five days (70 to 100 diploma days); – Survival fee of the larvae (to the primary feeding) is 60 to 80 p.c; – Measurement of fry at first feeding: 9 to 10 mm; – Measurement of the primary feed is 200 to 500 micron; – First feeding will happen 4 to five days after hatching; – Raceways used are of 100 to 200 litre capability; – Stocking density of the raceways is 50 to 100 fry/litre; – Rearing interval within the raceway: 15 to twenty days; – Optimum rearing temperature: 24°C; – Measurement of the 15 to twenty day outdated fry: 20 to 30 mm; – Measurement of feed at 15 to twenty days: 1 to 2 mm; – Survival fee of the fry via the rearing interval: 90 to 95 p.c; – Quantity of fry surviving at 15 to twenty days, from 1 kg (dry) eggs is 70 000 to 80 000.

2.4 Pike Perch

Species: Pike perch (Stizostedion lucioperca L.)
Habitat: Prefers oxygen wealthy waters. It lives in rivers, lakes, reservoirs and fish ponds
Feeding: It’s a carnivorous predator, feeding primarily on small fish

Weight at age intervals:

12 months Grams
1 10 – 20
2 100 – 200
3 400 – 700
4 800 – 1 200

2.4.1 Reproduction

In its pure atmosphere, it uncovers the roots of aquatic vegetation, depositing the ova amongst them. The male then fertilizes the eggs. It spawns in pairs, and guards the ova till they hatch. Temperature at spawning: 14°C.

2.4.2 Financial characterization

Its meat is excellent, and comprises no intramuscular bone. – Good sport fish; – In polyculture, it consumes small fish of no worth; – It doesn’t face up to properly the dealing with needed in harvesting and transportation, thus requiring terribly cautious remedy.

2.4.3 Propagation

Care of the brood inventory: – Within the autumn the brood inventory is harvested from pure waters or fish ponds;
– The inventory is positioned in wintering ponds with out segregation by intercourse;
– Wintering area requirement is 3 to 4 m2 per fish;
– Small fish, on the fee of 20 to 30% of the brood inventory by weight, are positioned within the pond;
– Steady water circulation should be ensured within the wintering ponds.

2.4.4 Sexual differentiation

– The feminine’s stomach is full, rounded and its normal space is white in coloration;
– The male’s stomach is flatter, its space grey.

2.4.5 Spawning in fish ponds

The spawning pond must be small in space (500 to 1 000 m2), and 1.5 to 1.8 m deep, – The underside should not be very muddy; – Spawning nests are ready for the fish, made both of willow roots (Salix), or of a particular synthetic fibre “spawning rug”; – The nest is sq., of 50 cm dimension; – The spawning nest is positioned on the underside and secured; – Females and males are positioned within the spawning pond in equal quantity; – Every pair requires 30 to 50 m2 space.

2.4.6 Hypophysation

– Hypophysation is carried out earlier than inserting the brood inventory within the spawning ponds; – The pulverized hypophysis of carp must be administered in 1 ml of a 0.65% salt resolution; – Hypophysis dosage by physique weight is 2.5 mg/kg for the feminine, 2 mg/kg for the male; – Three days after inserting the spawners within the pond, the nests are examined, and these containing ova are transferred to the hatchery; – Through the switch – if over a brief distance – the nests are lined with moist rags to stop their drying by wind.

2.4.7 Hatching

– The ova in their nests are ripened by sprinkling with water, the strategy developed by Woynárovich (Hungary); – The nests are positioned vertically on racks over troughs of concrete or fibreglass; – Above the racks sprinklers are deployed, which produce a effective spray on the nests; – Water temperature must be 12°C, ambient temperature 16-18°C thus the ova are ripened at 15-16°C; – Incubation requires 110 diploma days (6-7 days); – To stop the technology of fungus, malachite inexperienced must be utilized in a 1:100 000 resolution; – The nets are immersed within the resolution for 6-8 minutes, rinsed and changed on the rack; – If required, the remedy is repeated every day; – When the ova are assumed to be able to hatch, a number of of them are positioned in a glass containing water of 15-16°C temperature. If these hatch readily, the nests are positioned in hatching tanks; – The hatched larvae don’t have any pigmentation and are extraordinarily delicate to gentle; – The hatching tanks are due to this fact lined to maintain the larvae at nighttime; – The tanks should have a steady stream via of oxygen wealthy water; – Water temperature must be 12-14°C; – First feeding will happen at 6 to eight days; – First feed is zooplankton, measuring 50 to 100 micron; – The feeding fry are transferred to fish ponds, which include ample meals provides.

2.4.8 Organic and technical knowledge

– Age of sexual maturity, feminine: 3-4 years; male: 2-3 years
– Size of broodfish: 30-50 cm
– Weight of broodfish: 500-3 000 g
– Optimum water temperature: 10-14°C
– Intercourse ratio male to feminine: 1:1
– Amount of ova produced by the feminine is 150 000 – 200 000 per kg of physique weight;
– The diameter of dry eggs is 0.5 – 0.8 mm;
– The diameter of swollen eggs is 1 – 1.5 mm;
– Incubation interval: 6-7 days, 110 diploma days
– Hatching fee: 90-95%;
– Measurement of the larva: 4-5 mm;
– Measurement of first feeding fry: 6-8 mm.

2.5 Pike

Species: Pike (Esox lucius L.)
Geographical distribution: Europe, Asia, North America
Pure habitat: Rivers, lakes, backwaters and synthetic fish ponds. It prefers the perimeters, with vegetative progress of gradual or stationary waters
Feeding: The pike is a carnivorous predator, feeding on fish aquatic mammals, water fowl and vermin. It possesses a big urge for food, if ample meals is on the market it grows quickly.

Weight at age intervals:

12 months Grams
1 15 – 25
2 150 – 250
3 500 – 1 500
4 2 000 – 3 000

2.5.1 Reproduction

In a pure atmosphere, it spawns within the shallow waters close to the shoreline of lakes, gradual transferring rivers, and useless waters. The ova adhere to the underwater vegetation and will hatch there in 15 to 18 days. The pike doesn’t guard or have a tendency its eggs. The larvae droop themselves from the vegetation and keep thus till the resorption of the yolk sac in 8 to fifteen days. The primary feed consumed by the feeding fry is zooplankton.

In cultivation, the pike could also be positioned in fish ponds for spawning or propagated artificially in hatcheries. The spawning temperature is 5 to 12°C. Sexual maturity is attained at 3 to 4 years by the feminine, 2 to three years by the male.

2.5.2 Financial characterization

– The species is suited primarily to the stocking of pure waters;
– It is a superb sport fish;
– It’s meat is of good high quality;
– In fish ponds it can get rid of undesirable small fish which can be introduced in with the water provide.

2.5.3 Synthetic propagation

– A confirmed technique is the gathering of the ripe fish within the spawning season from pure waters. The gathering is finished utilizing fyke nets. The ripe ova is already flowing from the feminine. It’s fertilized and then taken to the hatchery and positioned in hatching jars. The mature fish stored in ponds or backwaters are collected within the autumn and positioned in wintering ponds; – Feeding is critical within the wintering ponds. This consists of inserting small fish within the pond, on the fee of 20 to 30 p.c, by weight, of the pike. The area requirement of the brood inventory within the wintering pond is 2 m2 per fish; – The pond ought to have a steady flow-through of oxygen wealthy water; – Measurement and weight at sexual maturity:

Female: 30 to 40 cm, 500 to 2 500 g
Male: 25 to 30 cm, 350 to 2 000 g

– Water temperatures required for propagation: in wintering ponds 6 to eight°C, in hatcheries 10 to 14°C.

2.5.4 Sexual differentiation

– The pike doesn’t show a marked dimorphism. The feminine, within the spawning season, may have a fuller stomach than the male. The male will emit white milt if pressed calmly. Sometimes the males have vivid yellow spots.

2.5.5 Hypophysation

– For the factitious induction of the manufacturing of ova and sperm in pike, hormone of the carp’s hypophysis is employed; – Previous to hypophysation, the brood inventory is collected from the wintering ponds. After hypophysation, the fish are stored in tanks or small ponds till the removing of ova and sperm from them; – Dosage;

for the feminine, 3 mg/kg of physique weight
for the male, 2 mg/kg of physique weight;

– The hypophysis is dissolved in a 0.65 p.c salt resolution. Two ml salt resolution per fish is used. The hypophysis is injected 72 hours previous to the removing of ova and sperm. The water temperature is maintained at 10°C; – After hypophysation, the males and females are positioned in separate tanks; – Every fish is supplied with 0.5 m3 of water within the tank. Water circulation required is 2 litres/min/fish. Saturation of the water with oxygen should be maintained; – The fish shouldn’t be fed whereas within the tanks. Tranquilization just isn’t employed.

The removing of ova and sperm, fertilization; – 72 hours after hypophysation, the tanks’ water degree is lowered and the fish are picked up by hand, one after the other. With slight strain, the ripe ova are simply made to stream out; – The ova are collected in plastic dishes; – Sperm will emerge from the male with slight strain on the stomach. The sperm is collected with pipettes; – Care should be taken that neither ova nor sperm come into contact with water; – Ova and sperm are completely blended, with out the addition of water, so that every ovum might be reached by the sperm. 8 to 10 ml sperm is used to every 1 000 g of eggs. Every batch of eggs is fertilized with sperm from at least 3 males to guarantee profitable fertilization; – A fertilizing resolution is used within the course of of fertilization. The composition of the answer is:

Water: 1 litre
Salt: 7 grams
Urea: 15 grams

– To 1 000 g ova, 150 to 200 ml fertilizing resolution is added, with steady stirring, utilizing a plastic spoon; – After two minutes, an extra 200 ml fertilizing resolution is added and the stirring motion continued; – After 5 minutes, the answer is rigorously poured off, then contemporary resolution added in a quantity that’s thrice that of the ova; – That is stirred for ten minutes, then the answer is poured off; – Recent water is poured on the ova, by which it will likely be soaked for 45 minutes; – The water is exchanged at ten minute intervals, with a cautious stirring at 5 minute intervals; – The rinsed ova could also be transported with out loss for 2 to 3 hours, in a 1:2 combination of ova to water.

2.5.6 Hatching

– The ova are positioned in hatching jars; – In a ten litre capability hatching jar, 1.5 to 2.0 litre ova could also be positioned. The ova will turn out to be considerably lumpy within the jar, however that is of no consequence; – The ova are delicate to water turbulence for the primary 48 hours, due to this fact, the water stream within the hatching jar is held to 0.5 l/min; – After 48 hours, the stream is elevated to 2.0 to 2.5 litre/minute. Presently the lumps are separated to stop adhesion with cautious stirring; – The water temperature within the jar must be 6 to eight°C in the course of the first two days, then step by step elevated to attain 12 to 14°C on the fourth day. The water temperature shouldn’t be raised above 14°C, since this is able to incapacitate the hatching larvae; – To stop the technology of fungus, the ova should be disinfected every day, starting with the third day after placement within the hatching jar. The disinfectant to be employed is malachite inexperienced, in a focus of 5 ppm, the period of the remedy is 5 minutes; – The infertile ova, that are lighter in color will rise to the highest and could also be siphoned off via a rubber tube; – Incubation requires 130 to 150 diploma days, relying on water temperature, the time required could fluctuate from 8 to fifteen days; – Upon hatching of the primary few larvae, the ova are transferred via rubber tubes, into giant plastic dishes; – The dishes include heat water, of 15 to 17ºC, by which the larvae hatch inside 10 to fifteen minutes.

Upkeep and transportation of the larvae: – The larvae are positioned in pens; – The larva pens are 70×40×30 cm in measurement, and are made of 1 mm nylon mesh; – The pens are stored in concrete or fibreglass tanks with flow-through circulation; – The pens are stocked on the fee of 150 to 200 larvae per litre; – Quickly after being positioned within the pen, the larvae will droop themselves from the partitions of the pen and stay in place for five to six days. They shouldn’t be disturbed throughout this time, since they are going to have problem in repeatedly reattaching themselves. The underside of the pen is rigorously cleaned of shells, the detritus being siphoned off via a rubber tube; – Water temperature is stored at 10 to 12°C; – Time span of the larval stage is 8 to 10 days; – The swim up fry is transferred to fish ponds. The fry is transported in polyethylene baggage; – At 10°C, 100 000 fry could also be stored in 20 litre water plus 20 litre oxygen for two to 4 hours; – The scale of the swim up fry is 8 to 10 mm.

2.5.7 Organic and technical knowledge

– Age of sexual maturity, feminine 3-4 years, male 2-3 years;
– Size of broodfish: 30-80 cm
– Weight of broodfish: 500-5 000 g
– Optimum water temperature: 6 – 12°C
– Intercourse ratio male to feminine: 2:1
– First hormone remedy of females: 2-3 mg/kg
– Second hormone remedy of females: 5-7 mg/kg
– Time between the 2 remedies: 24 hours
– Time between the second remedy and ovulation: 550-750 diploma hours
– Hormone remedy of males; 3 mg/kg
– Effectiveness of hormone remedy of the females: 70-80%
– Amount of eggs per feminine, dry weight: 200-800 g
– Amount of milt per male; 2-5 ml
– Amount of milt for fertilizing 1 kg of dry eggs; 4-8 ml
– Fertility fee of eggs: 40-60%
– Measurement of dry eggs: 2 mm
– Measurement of swollen eggs; 3 mm
– Rely of dry eggs per kg: 180 000 – 200 000
– Rely of swollen eggs per litre: 50 000 – 80 000
– Amount of swollen eggs in 10 litre hatching jar: 1.5 – 2.5 1
– Water stream in hatching jar; 0.5 – 2.5 l/min
– Time required for hatching: 120 diploma days
– Hatching fee: 80-90%
– Time of the larval stage: 100-120 diploma days
– Stocking density of larvae container: 150 – 200 larva/litre
– Quantity of first-feeding fry from 1 kg of dry eggs: 50 000 – 100 000
– Measurement of fry at first feeding; 11 – 14 mm

2.6 Semi-Synthetic Propagation of Indian Carps

Species: Catla catla (Hamilton) (Catla)
Labeo rohita (Hamilton) (Rohu)
Cirrhinus mrigala (Hamilton) (Mrigal)
Origin: India, Pakistan, Bangladesh, Burma
Pure habitat: Rivers, lakes, fish ponds
Feeding: Catla catla – zooplankton, phytoplankton in floor strata,
Labeo rohita – zooplankton, alongside the entire water column,
Cirrhinus mrigala – omnivorous backside feeder.

Age dependent measurement of fish

12 months Catla
mm
Rohu
mm
Mrigal
mm
1 250-380 290
2 280-510 511
3 415-660 670
4 510-750 797
5 550-810 858

2.6.1 Propagation

– Spawning in rivers throughout monsoon rains;
– Spawning may be induced semi-artificially;
– Optimum temperature of spawning is 26-31°C;
– Eggs are floating, not sticky.

2.6.2 Financial options

– Relevant in intensive polyculture applied sciences;
– Meat is tasty, essential meals.

2.6.3 Method of distinguishing male or feminine spawners

– The stomach of feminine is swollen, genital organ is pink;
– Upon gentle strain the male produces white milky drops;
– The exhausting ray of pectoral fin is tough with the male, and clean with the feminine.

2.6.4 Age of fish at first propagation

2-3 years.

2.6.5 Hypophysation

– Carp pituitary gland is used dried in acetone – Female spawners:

1st injection 2, 3 mg/kg, 10 – 12 hours earlier than ovulation;
2nd injection 5, 8 mg/kg, 4 – 6 hours earlier than ovulation;

– Hypophysation of males: 2-3 mg/kg, 4-6 hours earlier than stripping the milt; – Hypophysation is carried out with powdered pituitary gland, injected in 0.65% NaCl resolution, calculating 2 ml/fish.

2.6.6 Maintaining of spawners and spawning

– The injected males and females are transferred to a breeding hapa in a fish pond or tank with gradual water flowing; – Spawning is usually 4-6 hours after the 2nd injection; – After spawning the mother and father are taken out .

2.6.7 Hatching of the seed

– The fertile eggs within the hapa hatch 15-18 hours after spawning; – 12-14 hours after spawning – when the embryo begins transferring within the egg – the eggs are collected and transferred from the hapa to the hatching glass (Zuger glass); – The hatched larva slips from the breeding hapa to the outer narrow-meshed rearing hapa.

2.6.8 Rearing of larva

– The larva begins feeding 4-5 days after hatching;
– The fry at this stage is stocked in nursery ponds.

2.6.9 Organic and technical figures

– Age of sexual maturity. Female: 2-3 years, male: 1-2 years
– Size of broodfish: 40-80 cm
– Weight of broodfish: 200-6 000 g
– Optimum water temperature: 24-31°C
– Intercourse ratio male to feminine: 1:2
– Effectiveness of hormone remedy of the feminine: 60-80%
– Amount of eggs per feminine, dry weight: 200-2 000 g
– Fertility fee of the eggs: 30-40%
– Measurement of dry eggs: 1-1.5 mm
– Measurement of swollen eggs: 4-6 mm
– Rely of dry eggs per kg: 700 000-1 000 000
– Rely of swollen eggs per litre: 15 000-25 000
– Time required for hatching: 15-18 hours, 20-22 diploma days
– Measurement of fry at first feeding: 6-7 mm.

Reference

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