RU2200386C1 - Method for reproduction in crustacean (king crab) - Google Patents

Abstract

FIELD: pisciculture, aquaculture. SUBSTANCE: one should conduct roe females' catching at the final embryonic stage 5-10 d before larvae output, then they should be transported to incubation place for the period not exceeding 15 h at constant air supply, larvae are grown in zoea stage of I, II, III and IV stages, glaucotoe and the first stage of fry stage in one and the same tank with closed cycle of water supply at density of 50 pc/l, not more and water flow velocity of 1-2 l/min, not less. At zoea stage since the first day after birth and during the next 8-10 d water medium is additionally supplemented with suspension of diluted standard fodder for sea shrimps at the quantity of 50 ml/10000 larvae. Density of plankton content is chosen depending upon a stage (zoea IV). For I, II, III zoea stages fodder is given twice daily, and for IV stage - thrice daily. At raising at glaucotoe stage one should put down substrate beforehand, raising is carried out at water flow velocity of 1 l/min and density of 25 pc/l, zooplankton content density in water medium should be decreased up to 5 pc/d - once, at the first fry stage water temperature should be increased within the limits of 10-15 C, water flow velocity is increased up to 5 l/min, as fodder one should use shrimps and mussels' stuffing at the ratio of 3 : 1 at food coefficient of 3. Reproduction process is finished by transportation and release of fry into open sea. The innovation enables to regulate reproduction process in king crab due to obtaining sufficient quantity of viable fry. EFFECT: higher efficiency of reproduction. 5 cl, 2 tbl

Description

 The invention relates to fisheries, in particular, can be used in the field of industrial aquaculture in the reproduction of marine crustaceans. Lithodes, Order Decapoda, Suborder Anomura, fam. Lithodidae, genus Paralithodes, Paralithodes camtschaticus.

 The commercial development of the Kamchatka crab was extremely intense, without observing biologically sound catch standards. As a result, the population of Kamchatka crab was undermined as soon as possible. Kamchatka crab restoration is impossible without artificial reproduction.

 The problem of artificial reproduction of Kamchatka crab, as a possible way to replenish the number of significantly reduced natural populations, is actively discussed in the scientific and technical literature.

 Biotechnology for obtaining larvae and their maintenance in pools with specially maintained conditions increases the efficiency of reproduction compared to natural by an order of magnitude or more.

 The experience of keeping Kamchatka crab in aquarium conditions is known (Zubkova, 1964) [1].

 The purpose of the observations was to establish how the females will behave in the aquarium and how they will feed, and the main task was to observe the development of the eggs, remove the larvae from it, and obtain data on the first life stages of the larvae.

 Of the twelve females living in the aquarium, seven died during the year. The death of crabs was caused by their content in adverse living conditions in the aquarium. From the eggs of the surviving females, the larvae hatch, after which the females molted and laid new eggs.

 Female king crab was kept in a flowing aquarium. Due to the limited area and insufficient water exchange, saprolegnia appears, causing significant death of eggs. Of the total number of eggs hatched by females, only 10% survived.

 Long overexposure of females (from autumn to spring) in aquariums under uncontrolled conditions led to 90% mortality of fertilized eggs on their playopods. Hatching time (66 days) is too long. This leads to a large scatter of larvae by age and increased cannibalism.

 The feeding of hatched larvae began 3-4 days after hatching. The absence of a food source at the very beginning of ontogenetic development determines high mortality even at the first stage - zoea I.

 The massive development of ciliates and the growth of larvae with Limnopora paradoxa diatoms, the lack of control over environmental parameters and the absence of differentiated feeding depending on the needs of the larvae at each developmental stage are the cause of high mortality.

A known method of reproduction of crabs (options) (RF patent 2174750, IPC ⁷ A 01 K 61/00) [2].

The essence of the invention, the reproduction of crabs and craboids lies in the fact that the collection of crab larvae is carried out on collectors, on collector-cage systems or on cages, which are exposed to depths of 5-150 m in sea areas with a water temperature of not higher than 18 ^o C, salinity not lower 28% with dissolved oxygen in water of at least 5 mg / l. Growing fry are from 4 months to 3 years.

 The disadvantage of this method is that reproduction is carried out in vivo, without strict control and the ability to optimize environmental conditions and feeding conditions, which ultimately determines the survival of the larvae.

It is known to develop Kamchatka crab biotechnology using sea water in Aquatron-type apparatuses (Kovacheva, 2000) [3] from embryonic developmental stages to fry, mainly related to temperature control. The author noted that the creation of optimal temperature conditions (7-8 ^o C) when growing larvae in closed systems can significantly reduce the duration of the larval period of development. In the process of molting, crab larvae are most vulnerable. When moving from one larval stage to another, the waste amounted to about 10%. At the stage of glaucoma, the temperature was increased to 10 ^o C and maintained until the end of the experiment. Survival approximately corresponded to the value of this indicator for the Kamchatka crab grown on natural sea water.

 The nauplii of the gill-footed crustacean Artemia salina were used as food.

 During the juvenile developmental stage, crabs were fed mollusks, squid, crushed and nauplii artemia. However, the work does not present feeding conditions, feed compositions and diets in the early stages of development, which ultimately significantly affects survival.

 The closest solution to the claimed invention is presented in biotechnology recommended when receiving planting material for king crab in a pilot plant (Stepanov, Smirnov, 1999) [4]. The developed installation with a closed water supply system makes it possible to control and maintain specified environmental parameters (illumination, temperature, salinity, oxygen content, pH, redox potential).

 The disadvantage of this work is that the pilot installation did not pass approbation with obtaining larvae and juveniles until viable stages. Of the 3 Kamchatka crab females delivered from Vladivostok in April 1998, one female dropped eggs during transportation, while the other two showed abortive hatching of larvae a day after delivery. All larvae died within 3-4 days. The proposed biotechnology has several disadvantages: the conditions and optimal feeding conditions for each stage of development have not been worked out. The planting density of 100 pcs / l proposed by the authors has not been verified and does not meet the biological characteristics of the larvae (cannibalism is highly developed).

 The task to which the invention is directed is the restoration of king crab populations by obtaining a sufficient number of viable juveniles.

 The aim of our research was to develop a biotechnology for the reproduction and growing of Kamchatka crab to a viable stage in a system with a closed water supply cycle.

 The essence of the method of artificial breeding of king crab Paralithodes camtschaticus is that the production of viable juveniles is carried out in artificial controlled conditions while optimizing the regime of keeping and feeding at each stage of development of larvae and juveniles of the first stage.

 The process of artificial breeding of king crab includes three stages: the first stage lasting 35-40 days consists in growing larvae (zoea) and ends after the next molt with metamorphosis and transformation into glaukotoe. The second stage lasting 18-20 days is to grow glaucothae to fry. The third stage lasting 14-20 days consists in growing fry to obtain viable juveniles, followed by release into the sea.

. Кормление проводится один раз в сутки, при суточном рационе 0,5-1,0% от массы тела. В состав кормов входят кальмар, минтай, треска. С начала выклева температура воды постепенно повышается (1^oС/сутки) до 7-8^oС. Начало выклева рассчитывается заранее по изменению отношения площади желтка ко всей площади икринки (Onli et al, 1980). Выклев личинок от одной самки колеблется от 3 до 7 дней. Выклюнувшиеся личинки просчитываются и ежедневно переносятся в выростные бассейны. Для сбора личинок используется их реакция фототаксиса. Дальнейшее выращивание личинок (зоэа) проводится в бассейнах с замкнутой системой водоснабжения при плотности посадки не более 50 шт./л, скорости протока не менее 1 л/мин, при температуре воды 7-9^oС, рН в пределах 7,9-8,2, насыщении кислородом воды не менее 80%. За личиночный период развития зоэа проходят 4 стадии. Уже на ранних личиночных стадиях у камчатского краба отмечен каннибализм. В связи с этим соблюдается плотность посадки не более 50 шт./л и своевременное и достаточное обеспечение живыми кормами.The proposed method for the reproduction of king crab is that females with caviar at the last embryonic stage (5-10 days before hatching of the larvae) are transported to the incubation site with constant aeration and planting density of 10-12 pcs / m ² . At the same time, the duration of transportation should not exceed 15 hours. The content of females before hatching larvae is carried out in pools with a closed water supply system with a planting density of not more than 2 pcs. / m ² , the flow rate of water is not less than 5 l / min, the water temperature is not higher than 4 ^o C, pH in the range of 7.9-8.1, salinity 30 - 32

. Feeding is carried out once a day, with a daily diet of 0.5-1.0% of body weight. The composition of the feed includes squid, pollock, cod. From the beginning of hatching, the water temperature gradually rises (1 ^o C / day) to 7-8 ^o C. The hatch start is calculated in advance by changing the ratio of the yolk area to the entire egg area (Onli et al, 1980). The hatching of larvae from one female ranges from 3 to 7 days. Hatching larvae miscalculate and are daily transferred to outgrowth pools. To collect the larvae, their phototaxis reaction is used. Further growing of larvae (zoea) is carried out in pools with a closed water supply system at a planting density of not more than 50 pcs / l, flow rate of at least 1 l / min, at a water temperature of 7-9 ^o C, pH in the range of 7.9-8 , 2, oxygen saturation of water of at least 80%. During the larval period of the development of zoea, 4 stages pass. Kamchatka crab already has cannibalism in the early larval stages. In this regard, a landing density of not more than 50 pcs / l and timely and sufficient provision of live food is observed.

 The rate of development, growth, and survival of crab larvae to a large extent depends on their level of live food availability, adequate to the size, quantity and nutritional needs of the larvae at each stage of their development. An important point in the artificial cultivation of king crab is to provide larvae with food at the very beginning of their transition to active nutrition.

 Feeding of larvae (zoea I) begins on the 1st day after hatching with diluted Japanese shrimp food, containing 50% protein, 8% fat (EBI STAR-0), and artemia nauplii at the age of no more than 24 hours. The additional introduction of Japanese feed into the aquatic environment ensures the supply of crab larvae with a high-energy protein that complements the complex of essential nutrients supplied with artemia nauplii.

The following sequence of operations for feeding the king crab larvae is observed:
- cleaning the bottom of the remains of feed and exuvium;
- adaptation of nauplii brine shrimp to the temperature conditions of the pool for at least 30 minutes;
- the inclusion of light to concentrate the larvae in the place of feeding;
- shut off the water flow for 10 minutes;
- feeding a suspension of diluted feed for sea shrimp in the amount of 50 ml per 10 thousand pieces larvae (zoea I);
- the supply of artemia nauplii in an amount calculated in advance for each stage of development of the king crab (artemia cysts with an germination rate of at least 70% are selected for incubation);
- moving the light source with the repeated supply of suspension and nauplii to a new place in the pool.

 The consumption of live food depending on the stage of development of the larvae is given in table 1.

 The biotechnology of growing zoea, including feeding conditions, planting density, was worked out, improved, constant monitoring of growing conditions was introduced, mortality in the process of linking was reduced.

, рН 7,9-8,2, содержание кислорода в воде не менее 80%, скорость протока 1 л/мин, плотность посадки 25 шт./л.After the fourth molting of the larvae (zoea IV), the next stage of development occurs - glaucothoe. At this stage, subsidence begins. Substrates (floating nets, corals, red algae) are immersed in water in advance. The following growing conditions are supported: temperature 8-10 ^o C, salinity 30 - 32

, pH 7.9-8.2, oxygen content in water of at least 80%, flow rate 1 l / min, planting density 25 pcs / l.

 In connection with the transition of glaucomotoe to an endogenous form of nutrition, the feeding intensity decreases to 1 time per day, 5 pcs. nauplii brine shrimp for 2 copies. crab. The duration of the stage is 18-20 days.

After the next molt, glaucomotae pass to the first stage of the fry period of development. Cultivation is carried out in the same containers with a closed cycle of water supply under the same environmental conditions under which zoea and glaukotoe were grown. The water temperature is thermostated within 10-12 ^o C, the flow rate increases to 5 l / min due to the intensification of metabolism of juvenile king crab at this stage of development. For feed use shrimp and mussel forcemeat (in a ratio of 3: 1) with a feed ratio of 3. The intensity of feeding increases due to an increase in the frequency of feeding up to 2 times a day. The duration of the third stage is 14-20 days. At the end of the first fry stage, fry are released into the sea.

 The data obtained make it possible to regulate the reproduction process and recommend bio-standards for the production of king crab fry on an industrial scale.

 The technological scheme and bio-standards of the artificial reproduction of Kamchatka crab from the embryonic stages of development to the first fry stage (Table 2).

List of references
1. Zubkova N. A., 1964. Experience in keeping Kamchatka crab in an aquarium. Tr. Murm. marine. biol. Inst., issue 5 (9), p. 105-113.

2. Fedoseev V.Ya., Grigoryeva NI, 2001. The method of reproduction of crabs (options). RF patent 2174750 / IPC ⁷ , A 01 K 61/00. Bull. 29, 2001

 3. Kovacheva NP, 2000. Reproduction of Kamchatka crab (Paralithodes camtschaticus) using artificial sea water in apparatus such as "Aquatron". / Fisheries: Series Mariculture, analytical and abstract information / VNIERH, issue 4. S. 14-26.

 4. Stepanov D. N, B.P. Smirnov, 1999. Pilot installation for receiving planting material for Kamchatka crab. / Fisheries: Aquaculture Series: Information package "Aquaculture: Problems and Achievements" / VNIERH, issue 2..- S. 10-14.

Claims (6)

1. The method of artificial reproduction of crustaceans (king crab) Paralithodes camtschaticus, including the capture of eggs of females, their transportation, keeping in a closed water supply system under optimal conditions until hatching of larvae, the content of glaukotoe and fry of the first stage, characterized in that the capture of females with caviar is carried out on the last embryonic stage of development of eggs 5-10 days before hatching of larvae, the duration of transportation of females is not more than 15 hours with a constant supply of air, the maintenance of females is carried out in pools When planting density of not more than 2 pieces. / m ² and flow rates of at least 5 l / min.  2. The method according to p. 1, characterized in that the cultivation of larvae (zoea I, II, III, IV), glaucoma and fry is carried out in the same containers with a closed water supply cycle, subject to the feeding schedule, depending on the stage of ontogenetic development.  3. The method according to p. 2, characterized in that the cultivation of larvae (zoea I, II, III, IV) is carried out at a planting density of not more than 50 pcs. / l and flow rates of at least 1-2 l / min, moreover, at the stage of zoea I, from the first day after hatching for 8-10 days, an additional suspension of diluted feed for sea shrimp in the amount of 50 ml per 10 thousand pcs. . larvae (the number of introduced Artemia nauplii is chosen depending on the stage of development).  4. The method according to p. 3, characterized in that when growing larvae, the density of the content in the aquatic environment of artemia nauplii is increased, starting from 20 pcs. / copy / day at the first stage (zoea I) up to 50 pcs. / copy / day at the last stage of development of larvae (zoea IV), while at the I, II, III stages of zoea feed twice a day, at stage IV - three times a day.  5. The method according to p. 1 or 2, characterized in that when growing Kamchatka crab, substrates (floating nets, corals, red algae) are introduced in advance before reaching the glaucothae stage, while the cultivation is carried out at a flow rate of 1 l / min and a planting density of 25 pcs. . / l, due to the transition to the endogenous form of nutrition, the density of the content of Artemia nauplii in the aquatic environment is reduced to 5 pcs. / copy / day, feed is applied 1 time per day. 6. The method according to p. 1 or 2, characterized in that when growing the crab in the first fry stage, the water temperature rises to 10-12 ^o C (to increase the growth rate), the flow rate increases to 5 l / min, while as a feed minced shrimp and mussels are used in a ratio of 3: 1 with a feed ratio of 3.

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