There are as many as 12 kinds of lobsters, and the most common ones are Jinxiu lobster, Japanese lobster and China lobster. Splendid lobster is the largest, reaching 55 cm, while Japanese lobster is the smallest. Lobster is delicious, nutritious and magnificent, and is regarded as the king of shrimp.
market potential
Lobster is a high-value breed in the United States, France and other countries, but it has not been produced in large quantities in China. According to relevant data, at present, lobsters supplied by large and medium-sized cities in China are mostly imported products. Shanghai, Beijing and Guangdong import no less than10.5 million tons of live lobsters every year, accounting for 70% of the world's live lobster market. At present, China has become a big importer and consumer of live lobsters. Therefore, the potential of China's lobster market is enormous. However, due to the undeveloped artificial culture of domestic lobsters and the overfishing of natural lobsters for many years, the output is very small. At present, most of them are imported from Australia, India, South Africa, the United States and other regions. Due to the strong market demand in China, the world lobster price has been rising all the way. Now, depending on different varieties, the price of live lobster in Guangzhou market is as high as 190-400 yuan per kilogram.
There are also some lobster resources in China's coastal areas, especially in South China. Lobsters have the characteristics of long life cycle, storage and transportation resistance, miscellaneous eating habits, thin shell and plenty of meat, and fresh and tender meat. Some fishermen keep lobsters caught in nature for a short time, and then sell them when the price is high. The experimental results also show that lobster culture can be combined with pond culture and cage culture, and intensive culture and temporary culture can be combined. Two crops can be raised every year, each crop is 180 yuan, and the natural crayfish fry with the specification of 50-120g is adopted, and the average weight gain of lobsters is195-200g, and the yield per crop is more than 798kg, so the breeding benefit is very good. In this respect, there is a successful case in Zhanjiang City, Guangdong Province: in August of 1988, artificial breeding of lobsters began in the suburbs of Zhanjiang, and it was successful after three years of practice.
Breeding technology
Lobsters in nature mainly inhabit the sandy and muddy seabed, with one tail lurking in each hole. However, in the mating period, males and females pair up and sometimes lurk in the gaps of rocks, while Japanese lobsters live in groups. Lobsters must be fed during feeding, and it is necessary to consider whether various attached organisms can be used as bait.
1. water temperature: lobsters live in low water temperature. The lowest water temperature in winter is about 5℃-6℃, which is suitable for lobster culture. If the water temperature is low, the maturity will be extended to 5-7 years. Lobster has poor high temperature resistance. In the experiment, the water temperature was raised to 25℃, and there was no special abnormality for 2 weeks. According to the experiment, the suitable growth temperature is 20℃-23℃, and lobster grows fastest in water with water temperature of 20℃-22℃, so in winter when the water temperature drops, it is one of the methods to promote growth by using warm drainage.
2. Salinity: The suitable salinity range of lobster is 26.90‰-34.40‰, and it can live and metamorphose in seawater with low salinity of 23.50‰.
3. Bottom material: The metamorphosed larvae of lobsters turn to benthic life in order to avoid predation by natural enemies, and the sand in the bottom material is extremely important as a place for lurking and feeding. After metamorphosis for 3-4 days, lobsters can burrow and lurk in sand with a particle size of 0.4- 1.00 mm. After 8 days of metamorphosis, it can lurk in sand with a particle size of 2.0-3.0 mm.
4. Growth rate: For the lobster population before 1 age, it is only necessary to lay the bottom of the pond with oyster shells, instead of putting artificial shelter nests, and feed the mussels as bait. Since the 2nd instar, tetrachloroethylene pipes have been put into shelter nests, and the number of them is twice that of lobsters. In the population that has been cultured for two years, individuals with the maximum weight of about 300 grams appear, and the lobsters gain about 50% each time they molt. The lobsters molt at the beginning of the first year, and their weight can reach 450 grams when they are sexually mature. In the third-year population, 16% reaches sexual maturity.
The growth of lobster is related to bait, environment, water quality and molting times. Various baits and electrical stimulation have been tested. As a result, feeding fresh shrimp meat grows faster, which is 1 times faster than feeding fish meat. During the growth process, it usually molts more than twice a year, and it can molt four times when chemical drugs or electrical stimulation are used, and the growth rate increases 1 times. After the lobster molts, it will become active again after two weeks of hardening of the new shell. At this time, the food intake will increase greatly, and the feed amount must be increased by 30%.
5. Survival rate: Based on the fourth stage larvae of benthic life, the survival rate of the population below 1 age is slightly lower than 60%, but the survival rate of the population at 1-3 age is over 80%, and the survival rate of group feeding is 80%, which is a good feeding result.
It is observed that lobsters who meet each other in the pool often raise pincers' feet and threaten each other, but there is no phenomenon of killing lobsters with pincers' feet. Therefore, it is considered that the lobsters of 0- 1 age are raised in groups, and the benefits of individual isolation after 2 years old are higher.
6. Bait: After the fourth stage, the lobsters are specially fed with Mytilus edulis, which can promote the rapid maturity and reproduction of lobsters, and Mytilus edulis can meet the nutritional requirements of lobsters. Lobsters are omnivorous, and can be fed with artificial baits such as frozen small miscellaneous fish, shellfish and prawns. The daily feeding time is 1 time, preferably in the afternoon, and the feeding is stopped for 2 days 1 day, and the daily feeding amount is 5%- 12% of the shrimp weight. Always pay attention to the activities and food intake of lobsters, and clean the pond 1 time every year to prevent pollution. The results showed that the growth and survival rate of lobsters were better than those of mussels fed with the compound bait of Penaeus japonicus. For lobster, the optimum protein content in feed is 20%-25%, and it is expected that a compound feed suitable for lobster can be developed in the future. In addition, lobster preys on granular feed with the third palatal foot, so the individual size of lobster is not directly related to the particle size, and generally granular feed with small diameter can be used.