CN101622974B - Nereis seedling raising method - Google Patents

Abstract

A soilless seedling raising method for clamworm, the method is to use the water temperature of 27°C to 29°C, pH of 7.8 to 8.6, and salinity of 28 to 30, and the water for seedling raising is subjected to dark precipitation, secondary sand filtration, and then through a 300-mesh sieve It is used for filtering with silk bags; select the bodies of large, undamaged and vigorous individuals, and place them in a plastic bucket filled with ^0.5m3 seawater at a ratio of 3:1 for females and males to lay eggs and fertilize them. After washing the eggs three times, move them to the nursery pool. The larvae in the planktonic stage are mainly fed with Monocystis algae, and artificial compound feed is also added; Minced fish; in the process of nurturing clamworm seedlings, control the light between 300 and 1000 Lux according to its developmental stage. Using Gracilaria instead of sand as the attachment base for larvae, because Gracilaria can use the metabolites of clamworms as nutrition to promote its own growth and is easy to clean, it can improve the living environment of larvae, reduce the occurrence of diseases, and reduce the impact on larvae when they emerge. injury and improve the survival rate of larvae.

Description

Nereis seedling raising method

technical field

The invention belongs to the technical fields of agriculture, forestry, animal husbandry and fishery, in particular to a method for raising clamworm seedlings.

Background technique

The clam worm (Perinereis aibuhitensis Gnlbe) belongs to the annelid phylum, Polychaeta, Nereidida, Neteididae, Neteidinae, rich in protein, eicosapentaenoic acid , the economic value is extremely high. Its fat body is large, and it is a superior bait, known as "universal bait", and it is also a good variety for export and earning foreign exchange, about 10,000 US dollars per ton; secondly, it is a high-quality fresh bait for fish, shrimps and crabs, etc., or As an additive and attractant for aquatic bait, it can save bait in shrimp ponds, clarify water quality, and reduce shrimp diseases; at the same time, it inhabits estuaries, and its larvae and adults can be used as good biological indicators for detecting water pollution. There are abundant tidal flat resources along the coast of my country, and there is great potential for clamworm breeding.

At present, artificial breeding and breeding of clamworms are mainly concentrated in the coastal areas of Fujian, Jiangsu, and Zhejiang, and there are no relevant research reports in Guangdong and Guangxi in the south. In all domestic and foreign research reports, the traditional Nereist worm artificial nursery technology is to lay fine sand on the bottom of the nursery pond after the larvae develop to the late stage of 5-gang larvae, as the attachment base for the larvae. However, fine sand has the following disadvantages as the attachment base for larvae: one is that during the cultivation process, since the excrement and residual bait of the seedlings are buried in the sand, it is difficult to clean and easily cause diseases; the other is that it is very difficult to emerge. Emergence net cage can only adopt 80 mesh sieves because sand grains will leak out, and clam worm larvae are soft and soft in the shape of worms, and smaller larvae will escape from the emergence net cage. On the other hand, in order to make the sand leak out of the net cage, the net cage must be constantly shaken. At this time, the clam worm seedlings are caught in the sand and are easily injured, which reduces the survival rate of cultivation. Therefore, the improvement of the attachment base of clamworm seedlings to replace the traditional sand grains is a problem that should be studied in the artificial breeding of clamworm seedlings in the future.

Contents of the invention

The purpose of the present invention is in order to overcome the deficiency that above-mentioned prior art exists, according to nereis larvae need certain object as this life habit and characteristic of its attachment base when metamorphosis, and consider traditional sand grain attachment base cleaning difficulty and easy The invention has the disadvantages of causing diseases and easily damaging larvae during emergence, and provides a method for raising nereis worm seedlings.

In order to realize the above-mentioned invention object, the technical scheme that the present invention takes is that this Nereis worm seedling raising method comprises the following steps:

1. Nursery facilities and water: The nursery pond is a cement pond with a bottom area of about 30m ² , a depth of 1.5m, and a drainage hole at the bottom; the algae cultivation pond has a bottom area of 10m ² and a depth of 1.2m. Both the cultivation pond and the algae cultivation pond are equipped with Air stone; the water temperature of seawater for seedling cultivation is 27℃～30℃, pH7.8～8.6, salinity 28～30, after dark precipitation and secondary sand filtration, the specific treatment path is as follows: seawater → dark precipitation → primary sand filtration → secondary Grade sand filter → 300 mesh sieve silk bag → seedling pond or algae cultivation pond.

2. The selection of parent silkworms and the hatching of fertilized eggs: select the different clam worm bodies with large individuals, no damage in appearance and good vitality (nereis worms that are mature and about to breed), and place them in the tank in a ratio of 3:1 for female and male. 0.5m ³ plastic buckets of seawater, slightly inflated, after the complete oviposition and ejaculation of the worm body, let it stand for a period of time, after the fertilized eggs sink, use the siphon method to drain the seawater above, and then filter the seawater, repeat Do this three times to wash off excess semen. The fertilized eggs treated above are transferred to the nursery pool, and the density is controlled at 5-8 eggs/mL. Because the fertilized eggs of the clamworm are sinking eggs, in order to prevent the bottom from lack of oxygen, the amount of air inflation should be adjusted.

3. Selection and release of attachment substrate: When the larvae develop to the larval stage of the sarcopodia, the cilia on the body gradually decrease and no longer swim, and they begin to live on the bottom. Gracilaria growing in seawater with higher salinity was selected as the substrate for larvae. Clean the small shellfish, ciliates and other organisms attached to Gracilaria, thoroughly disinfect them with formaldehyde, and then put them into the bottom of the nursery pond where the larvae of the larvae of the sclerotia have grown to the late stage. /m ² (the weight of Gracilaria without dripping water). At this time, the amount of inflation should be controlled, because the gracilaria will float if the amount of inflation is too large.

Larval management:

4. Daily management: newly hatched larvae use the yolk sac in their bodies as their own nutrients, develop to the larval stage of larvae, the digestive tract begins to form, and the yolk sac disappears, so they need to be fed in time . Feeding at 8:00, 15:00 and 21:00 every day, mainly feeding single cell algae (Isochrysis zhanjiang, flat algae and cloud tail algae), and also throwing some artificial compound feed, the amount of feeding is based on the observation of larvae depends on the feeding situation. After the larvae lived in the bottom habitat, they were fed a small amount of minced fish; the artificial compound feed was shrimp chips and BB powder.

In the early stage of Trigonopod larvae to Pentaphyllum larvae, the larvae live in plankton, and then live in benthic crawling. In the planktonic stage, use the net bag to change about 1/3 to 1/2 of the water every day; when all the larvae live on the benthic crawl, drain the upper layer of water directly when changing the water, and change more than 50% of the water. Because the growth of Gracilaria requires a certain amount of light, the light intensity should be adjusted in time according to the developmental stage of the larvae during the nursery process. It is advisable to control the light intensity at 300-600 Lux in the planktonic stage, and between 400-1000 Lux after camping in the benthic life.

Add seawater to the depth of 80 cm in the algae culture pool, fertilize after disinfection with strong chlorine, and the nutrient salt formula for cultivating unicellular algae is NaNO ₃ 50 ppm, KH ₂ PO ₄ 5 ppm, FeCl ₃ 0.5 ppm, and then connect the algae species; The single-celled algae are Isoflagellates Zhanjiang, Pleurophytes and Cloudtails.

The method for nurturing clamworm seedlings of the present invention is an improvement on the attachment base of larvae in the traditional artificial seedling cultivation of clam worm. The traditional attachment base is sand grains, but the sand grains are difficult to clean and the breeding environment is easily polluted, causing diseases, and is easy to damage when emerging. larvae. The present invention uses the large seaweed Gracilaria to replace the sediment, which can optimize the breeding environment of the lugworm. Because Gracilaria, as the habitat of clamworms, is not only easy to clean and improve the environment, but also has many branches, and there is enough space for clamworms to inhabit. At the same time, Gracilaria can use the excrement of clamworms as their own nutrient purification. environment, promote the growth of Gracilaria and increase the yield, and Gracilaria can be sold as a commodity to increase economic benefits. This invention technology, while improving the survival rate of clamworm seedlings, does not need to separate the seedlings from the Gracilaria, and directly cultures the seedlings attached to the Gracilaria, reducing the damage to the larvae.

specific implementation

The Nereis worm seedling raising method of the present invention comprises the following steps:

1. The bottom area of the algae cultivation pool is about 10m ² and the depth is 1.2m. Place 6 loose air stones, add 80cm of water, disinfect the seawater with strong chlorine essence, and fertilize the seawater. The nutrient salt formula for cultivating unicellular algae is NaNO ₃ 50ppm, KH ₂ PO ₄ 5ppm, FeCl ₃ 0.5ppm, and then connect algae species (types include flat algae, dinoflagellates such as Zhanjiang, and cloud tail algae).

2. Select the different clam worm bodies (mature clam worms that are about to breed) that are relatively large, have no damage in appearance, and have good vitality, and place them in a plastic bucket filled with ^0.5m seawater in a ratio of 3:1 for female and male, and adjust The amount of gas is in a slightly boiling state. After the worm body has completely laid eggs and ejaculated sperm, let it stand for a period of time and after the fertilized eggs sink, use the siphon method to drain the upper layer of seawater, and then filter the seawater. Repeat this operation three times to wash Remove excess semen. The above-mentioned fertilized eggs are moved into the seedling pond with a bottom area of about 30m ² , a depth of 1.5m, and drainage holes at the bottom. The pool is laid according to the number of 1 airstone/5-6m ² , and the water temperature of seawater for seedling cultivation is 27°C-30°C , pH7.8～8.6, salinity 28～30, after dark precipitation and secondary sand filtration, the specific treatment path is as follows: seawater → dark precipitation → primary sand filtration → secondary sand filtration → 300 mesh sieve silk bag → seedling pond ; The hatching density of fertilized eggs should be controlled at 5-8/mL. Because the fertilized eggs of the clamworm are sinking eggs, in order to prevent hypoxia at the bottom, the amount of air inflated is slightly larger than when laying eggs.

3. When the water temperature is 27-29°C, it takes about 42 hours for the fertilized eggs to hatch the larvae of the trigonopod, and the newly hatched larvae use the yolk sac in the body as their own nutrients to develop to four The digestive tract of Arthropoda larvae begins to form, and the yolk sac disappears, so bait should be fed in time. Feed at 8:00, 15:00 and 21:00 every day, mainly feeding monocystis (Isochrysis zhanjiang, flat algae and cloud-tailed algae), and also throw some artificial compound feed (shrimp chips and BB powder) , The amount of feeding depends on observing the feeding situation of the larvae.

4. When the larvae develop to the stage of sarcopodia larvae, the cilia on the body gradually decrease and no longer swim, and begin to live in the benthic crawling, and it is necessary to put the attachment substrate in time. Clean the small shellfish, ciliates and other organisms attached to the Gracilaria, thoroughly sterilize them with formaldehyde, spread them evenly on the bottom of the pool, and put them in an amount of 2.5-3 kg/m ² (weight of Gracilaria without dripping water) ). At this time, attention should be paid to controlling the amount of inflation, because the gracilaria will float if the amount of inflation is too large. After all the larvae live in benthic crawling, in addition to feeding single cell algae and artificial compound feed, a small amount of minced fish is also fed.

5. During the pre-stage of the three-gangpod larvae to the five-gangpodia larvae, the larvae live in plankton, and change the water with a net bag for about 1/3 to 1/2 every day; when all the larvae live in the benthic crawling, change the water Drain the upper layer of water directly, and change the water volume by more than 50%. Because the growth of Gracilaria requires a certain amount of light, adjust the light intensity according to the developmental stage of the larvae during the nursery process. It is advisable to control the light intensity at 300-600 Lux in the planktonic stage, and between 400-1000 Lux in the benthic life. During the rearing period of larvae, check the density of larvae frequently, and increase the number of Gracilaria appropriately.

Claims (6)

1. clam worm seedling-cultivating method is characterized in that according to the following steps:

(1) culture facility and water: nursery pond is the about 30m of floor space ², the dark 1.5m in pond, bottom have the cement pit of osculum; Algae culture pond floor space 10m ², dark 1.2m cultures pond and algae culture pond and lays gas stone; Grow seedlings 27 ℃～30 ℃ of the water temperatures of seawater, pH7.8～8.6, salinity 28～30 after obscure shallow lake, the husky filter of secondary, is used behind 300 mesh sieve thin,tough silk bag filtrations again;

(2) selection of close silkworm and fertilized egg hatching; Selection is individual greatly, appearance does not have the good heteronereis of the vigor of injuring, and places in ratios female, male 3: 1 to fill 0.5m ³The Plastic Drum of seawater, little qi of chong channel ascending adversely treats that heteronereis lays eggs fully and arrange smartly, takes out close silkworm, moves into nursery pond after washing ovum three times, incubating oosperm density is controlled at 5～8/mL, regulates aeration quantity;

(3) squab three just saved nectochaeta larva with the nutriment of the yolk sac in the body as self, growth to four is the joint nectochaeta larva phase just, digestive tract begins to form, yolk sac disappears, the bait of need in time throwing something and feeding, the 8:00 of every day, 15:00 and 21:00 throw something and feed, the unit cell algae of mainly throwing something and feeding, hold concurrently and throw some artifical compound feeds, feeding volume is the ingesting situation of the young and deciding according to the observation, and when just joint nectochaeta larva phase of paedomorphosis to five, the cilium on its body reduces no longer swimming gradually, begin to enter the end life of crawling of dwelling, need in time to throw in adherance;

(4) in three just joint nectochaeta larvas to five just joint nectochaeta larva early stages, the life of swimming of young battalion is sought the end to dwell and crawl to live afterwards, and in the stage of swimming, change water about 1/3～1/2 with mesh bag every day; All seek the end when the young and dwell and crawl after the life, direct row's upper water when changing water, quantity of exchanged water is more than 50%;

Described adherance is a fragrant plant mentioned in ancient texts, and the fragrant plant mentioned in ancient texts of selecting should be grown in the higher environment of salinity, wash the harmful organisms that is attached on the fragrant plant mentioned in ancient texts simultaneously, and with throwing in after the formaldehyde thorough disinfection, supply volume is 2.5～3 jin/m ², refer to not have the fragrant plant mentioned in ancient texts weight of dripping.

2. according to the described clam worm seedling-cultivating method of claim 1, it is characterized in that: the young is all sought the end and dwells and crawl except that throw something and feed unit cell algae and artifical compound feed, hold concurrently to throw a spot of fish meat emulsion simultaneously after the life.

3. according to the described clam worm seedling-cultivating method of claim 1, it is characterized in that: the illumination of fragrant plant mentioned in ancient texts growth, according to the developmental stage timely adjustment intensity of illumination of the young, the stage of swimming is controlled at 300～600Lux and is advisable in seedling raising process, and battalion impinges upon between 400～1000Lux in life time of dwelling at the end.

4. according to the described clam worm seedling-cultivating method of claim 1, it is characterized in that: it is dark to add seawater 80cm in the described algae culture pond, and with strong chlorine oil sterilization back fertilising, the nutritive salt prescription of cultivating the unit cell algae is NaNO ₃50ppm, KH ₂PO ₄5ppm, FeCl ₃0.5ppm, connect the algae kind afterwards.

5. according to claim 1 or 4 described clam worm seedling-cultivating method, it is characterized in that: described unit cell algae is Zhanjiang Isochrysis galbana, flat algae and cloud tail algae.

6. according to the described clam worm seedling-cultivating method of claim 1, it is characterized in that: described artifical compound feed is prawn slice and BB powder.