Hippocampal culture technique

Seahorse (Hippocampus sp.) is a valuable medicinal marine fish, known as "southern ginseng". It has been evaluated as early as in the Compendium of Materia Medica, which has the effects of strengthening the body and tonifying the kidney, strengthening the heart, dispersing phlegm, reducing fever, relieving pain and stopping bleeding. It has a wide range of uses, a large market, and the market is in short supply. And the seahorse grows fast and has strong fecundity, so it is a promising breeding variety. However, at present, the biological research on hippocampus is not systematic, although culture has been carried out in some areas, but the culture technology is still very immature, especially the harm of diseases is serious, and new experience needs to be obtained in theoretical research and culture practice. The main results are as follows: 1. The biological hippocampus of the hippocampus is a small fish in the coastal shallow sea (Hippocamps), which belongs to Coleoptera, Coleoptera, Colosauridae and Hippocamps. There are 6 species of hippocampus distributed in the sea area of China, including coronatus, spinous hippocampus, greater hippocampus (H, kuda), macular hippocampus (H. trimaeutatus), Kirschner seahorse (Hmemkell0ggi) and Japanese seahorse (H, japonicus). The species of culture are mainly spotted hippocampus and large seahorse, and most of them are cultured in macular hippocampus. (1) morphological characteristics the external morphology of the hippocampus is more or less the same. The body length of zebra horse is generally 10-17cm. The side of the body is flat, the head is like a horse's head, and the abdomen is obviously protruding. The torso is seven-angled, the tail is quadrangular, and the tail is longer and thinner and curls to the ventral side, which is used to curl seaweed and so on. The kiss is slender, tubular, and the mouth is very small, located on the dorsal side of the head. The head is at right angles to the driving cadres. The whole body of the hippocampus is scaleless and completely surrounded by the bone ring. The fish is generally brown, but with the change of the habitat, the body color can change and tend to be consistent with the environment. There is a black round spot on the back of the body ring 1, 4 and 7 on the body side, so it is called trimaculate hippocampus, which is the main feature to distinguish this species. The ventral side of the tail of male fish has a special bag-shaped organ-pouch. The sea horse is stout, with a body length of 12-23.5cm, with a dilated abdomen and a large head, approximately at right angles. The small spines are well developed, the kiss is tubular and thick, and the body color is dark. The Japanese hippocampus is small in shape and 4.5~9cm in length. The kissing tube is short. The abdomen is dilated. Among the rings of the body, the dorsal spine is the most developed, and there are dendritic linear objects on the spines of the bone process. When mimicry occurs in the face of an enemy, this line will increase. (2) Ecological habits 1. Habitat and exercise hippocampus because of its mimicry adaptation characteristics, habits are also special, like to inhabit the subtidal zone where algae or leek thrive. Sex is very lazy, often with a curly tail attached to the stems and branches of seaweed, sometimes hanging upside down on floating seaweed or other objects, drifting with the current. Even if you temporarily leave the attachment for feeding or other reasons, you will find other objects attached to it after swimming for some distance. The swimming posture of the seahorse is very graceful, the fish body upright in the water, completely rely on the dorsal fin and pectoral fin high frequency wave swing (10 times per second) for slow swimming (only 1-3 m per minute). The activity of the hippocampus is usually in the daytime (morning and afternoon), and it is still at night. Seahorses often cackle because of pharyngeal muscle contraction when the water quality is deteriorating, lack of oxygen or being attacked by enemies, which sends a "cry for help" signal to breeders, but it also makes a sound when eating bait on the water, which should be distinguished. 2. Adaptation to environmental conditions. Water temperature: the suitable temperature range of hippocampus is generally between 12-32 ℃, and the optimum water temperature is 28. ℃ left and right. The adaptation of several kinds of seahorses to water temperature is shown in Table 2-8. Salinity: seahorse is a widely salty fish, which can live in the salinity range of 10-3 ‰. The ability of newborn seedlings to adapt to salinity is poor, and the salinity is generally required to be more than 15 ‰. In the long-term low-salt environment, the pro-hippocampus can not reproduce normally, and the salinity is above 10 ‰. Dissolved oxygen: although the activity of the hippocampus is weak, but the demand for oxygen in the water is very large, generally requires dissolved oxygen above 3m1/L, if the dissolved oxygen is lower than 2.5m1/L, the hippocampus is trapped in a state of hypoxia, its performance is generally reduced appetite, floating head, breathing and sound, and even random collision, and finally sink to the bottom of death. Pro-hippocampus and young hippocampus need more oxygen during childbearing. Illumination: the hippocampus has certain requirements for light intensity, and the light is too weak, which is not conducive to the activity and feeding of the hippocampus. For a long time, the light is too weak, the vision of the hippocampus decreases, and even blindness. But also avoid direct sunlight. When the light is too strong, algae multiply in large numbers, which often causes all kinds of diseases. The hippocampus has phototaxis, especially the seedlings are prone to phototaxis, so attention should be paid to the death caused by local hypoxia. The suitable light range of hippocampus is 3000-6000lx. The transparency of water should be about 1.5m. PH value: the suitable pH value of sea water for hippocampus is between 7.8 and 8.4. 3. the feeding habit of the hippocampus is to swallow food by the stretching activity of the operculum and kiss, and the size of the bait does not exceed the diameter of the kiss. It has a certain selectivity to the type and freshness of the bait. The foraging distance of the seahorse is only about 1 m, so the bait should be placed in the regular colony. The hippocampus in the natural sea area mainly feeds on small crustaceans, mainly flexopod, barnacle larvae, shrimp larvae and adults, fluorous shrimp, Mysis shrimp and hook shrimp and so on. Under the condition of artificial feeding, the effect of feeding on Mysis shrimp and cherry shrimp was the best, followed by pods and telopods. Freshwater cladocera can also be eaten, but attention should be paid to avoid pollution due to rapid death in sea water. The food intake of hippocampus is closely related to water temperature and water quality. In the range of suitable temperature, if the water temperature is high, the food intake is large and the digestion is fast. When the water quality is bad, the food intake is reduced, or even stopped eating. Under normal conditions, the daily food intake of the hippocampus accounts for about 10% of the body weight. The hippocampus has a large food intake at one time, and the hunger tolerance is also very strong. The hunger tolerance time from the newborn larva to the adult fish can be up to 4ml 132 days. (3) the growth rate of the hippocampus is relatively fast, and it can reach the parent size after only a few months of feeding after the seedling is produced. Of course, this also varies greatly with different species, and the growth of species in the south is generally faster. Under the condition of artificial culture, the lifespan of seahorse is more than 5 years, its body length is 18cm, and that of spotted hippocampus is more than 3 years, while that of Japanese seahorse is more than 2 years, and its body length is about 8-9cm. 1. Males and females recognize that there is a pouch on the ventral side of the male hippocampus (located at the back of the anus). When the first reproduction comes, the sac is formed by the skin strokes protruding from the ventral side of the tail, leaving only the unended foramen. The end of the cloacal cavity of female fish is also more or less dilated during the spawning period, forming reproductive papillae. In addition, the individual of the male seahorse is generally slightly larger than the female. 2. The time of sexual maturity of hippocampus varies with species, temperature and food condition. The time for several kinds of hippocampus to reach sexual maturity is 4-10 months for trimacularis, 9-12 months for sea horses, and 3-8 months for Japanese seahorses. The time range of sexual maturity in the same sea-Macedonia fluctuates greatly, which is mainly related to the water temperature. Take the three-spotted seahorse as an example, under the right temperature, the fry born in May of that year can reproduce in October (about 5 months). Those born in August tend to be in estrus from March to May of the following year. There is a similar situation in other seahorses. 3. Reproduction rate the reproduction rate of hippocampus varies greatly according to different species and nutritional conditions. Generally speaking, adult seahorse fish have the ability to reproduce, such as trimacularis and sea horses account for about 20-80%; Japanese seahorses account for 50-80%. Under good feeding conditions, pro-hippocampus can reproduce several to more than a dozen babies a year (April-November, Guangdong). The number of seedlings per fetus generally ranges from tens to more than a thousand, such as hundreds to 1200 for trimacularis and sea horses, and tens to 1200 for Japanese seahorses. The number of seedlings produced in the first sexual maturity of hippocampus was less, and then gradually increased. 4. Breeding period and breeding mode the breeding season of hippocampus in southern China is generally from April to November, in which June to September is the peak, and the peak is in July. In the north, the spawning period is later and the time is shorter. The water temperature in breeding season is 20-28 ℃, and the peak period is 26-28 ℃. The fry produced at this time have good quality, high survival rate and fast growth, but are poor in other seasons. Fish fry in the rising water temperature season are easier to cultivate than those propagated in the declining period, so in terms of production, we should strive for early cultivation of seedlings every year to facilitate the growth of seahorses. In the breeding season, sexually mature female and male seahorses tend to be in estrus in the morning, when both chase side by side, swim rapidly, and the melanin on the body surface shrinks and decreases and is yellowish white. After the excitement reaches the best part, the female and male fish are close to each other, from juxtaposition to relative swimming, and the male hippocampus bends to the abdomen, opening the mouth of the pouch, and at this moment receives the eggs from the female and is fertilized in the pouch. 5. after 8-20 days of embryonic development, the fertilized egg finally forms a small hippocampus produced by the male's pouch. Take the Japanese seahorse as an example, its egg diameter is 1-1.5mm. The newly hatched larvae are about 3.5mm, and the body ring has not appeared yet. The link begins to appear during 5mm. Only the larvae around 8mm produce the pouch. However, the development of the link has not been completed, and there are only 4 body rings and 3 caudal rings. The process of seahorse larval production is also very interesting. The male fish in the stage of delivery rolls its tail tightly on the seaweed, swinging back and forth, each time lifting up the small hole that presses the nursery sac and ejecting a small seahorse, but sometimes it takes more than a dozen times to give birth to a small fish. The newborn seahorse can curl on the nearby seaweed independently, and the male seahorse that gives birth to the seedling is in estrus quickly.