Lobster larvae metamorphosis within 11 days after hatching, with a survival rate of 50%. After the benthic life, the survival rate of the rearing group was 70%. The mussels were fed to the third instar, and the lobsters began to spawn at the fourth instar, and the fifth instar females. 60% of individuals hold eggs.
The copulation behavior of lobsters is generally carried out between freshly clam-shelled females and uncockroached males. The lower body edge of the individual's chest pedicle approaching the shell stage darkens, and the intersegmental membrane at the dorsal junction of the frontal thoracic and abdomen segments swells. According to these appearance characteristics, it is possible to judge that the lobster is about to develop clam shells. At the beginning of the shell, the cephalic metacarpal and caudal junctions cracked. The head and thorax first emerged from it, followed by a jump in the tail and the old shell fell off. From the beginning of the shell to the end of about 27 minutes, if the shell was disturbed, stay temporarily stopped, after Continuing with the successful completion of the oyster shelling process, some or all of the lobsters that are broken off by the appendages and the tail fan can be recovered completely by the pods and the individuals are also growing.
Females who have just shelled their shells are in a state of softness. It takes about several hours to start gaining weight. At this time, males can be placed in copulation. The mating time is 15-60 minutes. After the female shell is crusted, the shell gradually hardens. Hardened crust causes difficulty in copulation.
1. Incubation of larvae: Incubation of lobster larvae usually begins in May and June. The egg granules are brown to black after fertilization. Before hatching, the granules become transparent red. The opaque ones are dead eggs. An individual's incubation takes 10-20 days, but the incubation period is only a few days. The incubation time starts from the day the sun just sets to the middle of the night. The newly hatched larvae floated in the surface layer and, with the water flow concentrated in the gutters of the outlet, the larvae of the planktonic surface layer were captured in the morning on the second day.
Female lobster ovulates within 20 hours of copulation. It takes approximately 30 minutes for spawning to occur. The eggs are tightly attached to the egg bristles and then hatched after 3 weeks. Within 3 days of the unfertilized egg, the female lobster falls off from its abdomen. Spawning water temperature is usually about 28 °C better. The temperature is high, the egg is susceptible to deterioration, the incubation time is long when the temperature is low, and there are many deformed eggs. Therefore, the control of the water temperature is very important.
It has been observed that the number of eggs held by broodstock individuals with 72mm and 157mm cephalothorax is 5,240 and 48,850, respectively. If the eggs are not properly cultivated, the dead eggs will increase or the eggs will fall off. When the lobster is conceived, the eggs will be frightened. The easy-to-trip attendant, with a significant reduction in the number of hatching, and an egg-bearing individual weighing about 1.5 kg, was reared in Japan for 2 months. The result was that the number of hatched juveniles was 1678-1137 (mean should be 7005).
2, planktonic larvae: the newly hatched lobster is a red larvae, and then becomes a transparent, flat frond, only see a pair of black eyes in the sea, if you do not pay attention to see, can not see what creature, in addition to the eyes In addition to many prominent bristles, the bones are soft and free of calcareous and must be transmuted three times for about six months before they become adult lobsters.
The hatching first stage larvae were reared in water with a water temperature of about 20°C, and were fed with Artemia feed sufficiently. They developed to the second stage larvae within 2 days, and then developed to the third stage larvae after 3 days, and then passed through 4-5. Days develop to stage IV larvae until metamorphosis, that is, the minimum planktonic life period before hatching is 9-10 days.
After 20 days of egg hatching, the seedlings became lighter on day 1 after hatching, and body color became clear and watery on 22 days. With a little pigment, the antennae became longer and pods were covered, and the first pair of tail fans were covered with bristles on the outside. Starting from this work, the first is a rotifer, and food will be full or no food will die. In addition to food, vitamins must also be added to enable larvae to survive for a long time.
3, planktonic larvae and water flow: In general, the gas is an extremely effective measure to raise crustacean larvae, but the storm gas can not be too strong, if the use of strong gas measures, larvae appear between the head and breastplate Caused the larvae to die. With the development of lobsters, after the larva sinks into the pool, lobsters are generally difficult to float to the surface of seawater as long as they do not produce a strong current from the bottom. If the violence is too strong, the larvae's body surface and pupa are easily covered by organic matter at the bottom of the pool, affecting larval activity and respiration, causing physical weakness.
4, planktonic larval food: Lobster larvae prey animal plankton, Artemia nauplius larvae is a suitable diet for the first larvae. After the second period, the amount of food needed is larger. Chlorella cultured in seawater or marine yeast can be fed to Artemia nauplii, which is fed as larval larval bait for 10 to 14 days. Although non-active baits, such as fish and shellfish, can be used, their bait value is poor due to their lack of buoyancy. The results of feeding various feeds are shown in Table 1, and they are fed live brine shrimp and frozen brine shrimp. The survival rate is very different. To achieve a survival rate of 50%, only live brine shrimp can be used as bait.
It is generally believed that lobster larvae do not directly need phytoplankton, but the survival rate of lobster larvae tends to increase in the pool of unicellular green algae. It may be that the propagation of chlorophytes has a good impact on the stability of water quality and therefore cannot be ignored. The effect of unicellular algae, diatoms and zooplankton breeding in the outdoor conditions is the main reason that the survival rate of larvae does not decrease.
Table 1 Feeding of lobster larvae fed various feeds Survival rate (%) of the first mantissa to phase IV of the diet
Shell meat slices 2500-3000 10-12
Bovine liver fines 2500-3000 15-18
Bovine heart shreds 2500-3000 15-20
Frozen Artemia 2000 35-40
Live Artemia 2000 75-80
Minamata 2000 55-65
5. Perverted larvae: Stage IV larvae have an adult form and are ecologically transitional from planktonic life to benthic life. About 2 days after metamorphosis, the lobster larvae begin to dig nests adjacent to sediment-laden sand and gravel, and each pebble submerges the tail-tailed individuals. Phase IV takes about 12 days and develops to Phase V. The larvae only lurk in the first lair, and they generally do not leave the lair unless they catch the bait in a very short period of time.
The larvae that grow in nature only prey on small animals such as amphipoda and polychaetes. Because the lobster larvae have the potential to hide in the enemy, they can escape from predation by the enemy. However, this habit is not a physiologically necessary condition. The lobster cannot dig in the bottom of the nest and can be kept in a cage. The fourth stage larvae are stocked in concrete pools with oyster shells at the bottom, and the survival rate is about 80%. Lobster larvae are usually stocked as post-alien larvae as seedlings, but stage IV larvae do not fully enter benthic life, which is the cause of death after stocking.
The lobster generally develops into the fourth larvae 10 to 14 days after hatching. The peak period of the fourth larvae occurs 11-13 days after hatching. The lobster planktonic larvae are predatory sport baits, from the biological point of view It is effective to keep the lobsters with rubble angles.
The copulation behavior of lobsters is generally carried out between freshly clam-shelled females and uncockroached males. The lower body edge of the individual's chest pedicle approaching the shell stage darkens, and the intersegmental membrane at the dorsal junction of the frontal thoracic and abdomen segments swells. According to these appearance characteristics, it is possible to judge that the lobster is about to develop clam shells. At the beginning of the shell, the cephalic metacarpal and caudal junctions cracked. The head and thorax first emerged from it, followed by a jump in the tail and the old shell fell off. From the beginning of the shell to the end of about 27 minutes, if the shell was disturbed, stay temporarily stopped, after Continuing with the successful completion of the oyster shelling process, some or all of the lobsters that are broken off by the appendages and the tail fan can be recovered completely by the pods and the individuals are also growing.
Females who have just shelled their shells are in a state of softness. It takes about several hours to start gaining weight. At this time, males can be placed in copulation. The mating time is 15-60 minutes. After the female shell is crusted, the shell gradually hardens. Hardened crust causes difficulty in copulation.
1. Incubation of larvae: Incubation of lobster larvae usually begins in May and June. The egg granules are brown to black after fertilization. Before hatching, the granules become transparent red. The opaque ones are dead eggs. An individual's incubation takes 10-20 days, but the incubation period is only a few days. The incubation time starts from the day the sun just sets to the middle of the night. The newly hatched larvae floated in the surface layer and, with the water flow concentrated in the gutters of the outlet, the larvae of the planktonic surface layer were captured in the morning on the second day.
Female lobster ovulates within 20 hours of copulation. It takes approximately 30 minutes for spawning to occur. The eggs are tightly attached to the egg bristles and then hatched after 3 weeks. Within 3 days of the unfertilized egg, the female lobster falls off from its abdomen. Spawning water temperature is usually about 28 °C better. The temperature is high, the egg is susceptible to deterioration, the incubation time is long when the temperature is low, and there are many deformed eggs. Therefore, the control of the water temperature is very important.
It has been observed that the number of eggs held by broodstock individuals with 72mm and 157mm cephalothorax is 5,240 and 48,850, respectively. If the eggs are not properly cultivated, the dead eggs will increase or the eggs will fall off. When the lobster is conceived, the eggs will be frightened. The easy-to-trip attendant, with a significant reduction in the number of hatching, and an egg-bearing individual weighing about 1.5 kg, was reared in Japan for 2 months. The result was that the number of hatched juveniles was 1678-1137 (mean should be 7005).
2, planktonic larvae: the newly hatched lobster is a red larvae, and then becomes a transparent, flat frond, only see a pair of black eyes in the sea, if you do not pay attention to see, can not see what creature, in addition to the eyes In addition to many prominent bristles, the bones are soft and free of calcareous and must be transmuted three times for about six months before they become adult lobsters.
The hatching first stage larvae were reared in water with a water temperature of about 20°C, and were fed with Artemia feed sufficiently. They developed to the second stage larvae within 2 days, and then developed to the third stage larvae after 3 days, and then passed through 4-5. Days develop to stage IV larvae until metamorphosis, that is, the minimum planktonic life period before hatching is 9-10 days.
After 20 days of egg hatching, the seedlings became lighter on day 1 after hatching, and body color became clear and watery on 22 days. With a little pigment, the antennae became longer and pods were covered, and the first pair of tail fans were covered with bristles on the outside. Starting from this work, the first is a rotifer, and food will be full or no food will die. In addition to food, vitamins must also be added to enable larvae to survive for a long time.
3, planktonic larvae and water flow: In general, the gas is an extremely effective measure to raise crustacean larvae, but the storm gas can not be too strong, if the use of strong gas measures, larvae appear between the head and breastplate Caused the larvae to die. With the development of lobsters, after the larva sinks into the pool, lobsters are generally difficult to float to the surface of seawater as long as they do not produce a strong current from the bottom. If the violence is too strong, the larvae's body surface and pupa are easily covered by organic matter at the bottom of the pool, affecting larval activity and respiration, causing physical weakness.
4, planktonic larval food: Lobster larvae prey animal plankton, Artemia nauplius larvae is a suitable diet for the first larvae. After the second period, the amount of food needed is larger. Chlorella cultured in seawater or marine yeast can be fed to Artemia nauplii, which is fed as larval larval bait for 10 to 14 days. Although non-active baits, such as fish and shellfish, can be used, their bait value is poor due to their lack of buoyancy. The results of feeding various feeds are shown in Table 1, and they are fed live brine shrimp and frozen brine shrimp. The survival rate is very different. To achieve a survival rate of 50%, only live brine shrimp can be used as bait.
It is generally believed that lobster larvae do not directly need phytoplankton, but the survival rate of lobster larvae tends to increase in the pool of unicellular green algae. It may be that the propagation of chlorophytes has a good impact on the stability of water quality and therefore cannot be ignored. The effect of unicellular algae, diatoms and zooplankton breeding in the outdoor conditions is the main reason that the survival rate of larvae does not decrease.
Table 1 Feeding of lobster larvae fed various feeds Survival rate (%) of the first mantissa to phase IV of the diet
Shell meat slices 2500-3000 10-12
Bovine liver fines 2500-3000 15-18
Bovine heart shreds 2500-3000 15-20
Frozen Artemia 2000 35-40
Live Artemia 2000 75-80
Minamata 2000 55-65
5. Perverted larvae: Stage IV larvae have an adult form and are ecologically transitional from planktonic life to benthic life. About 2 days after metamorphosis, the lobster larvae begin to dig nests adjacent to sediment-laden sand and gravel, and each pebble submerges the tail-tailed individuals. Phase IV takes about 12 days and develops to Phase V. The larvae only lurk in the first lair, and they generally do not leave the lair unless they catch the bait in a very short period of time.
The larvae that grow in nature only prey on small animals such as amphipoda and polychaetes. Because the lobster larvae have the potential to hide in the enemy, they can escape from predation by the enemy. However, this habit is not a physiologically necessary condition. The lobster cannot dig in the bottom of the nest and can be kept in a cage. The fourth stage larvae are stocked in concrete pools with oyster shells at the bottom, and the survival rate is about 80%. Lobster larvae are usually stocked as post-alien larvae as seedlings, but stage IV larvae do not fully enter benthic life, which is the cause of death after stocking.
The lobster generally develops into the fourth larvae 10 to 14 days after hatching. The peak period of the fourth larvae occurs 11-13 days after hatching. The lobster planktonic larvae are predatory sport baits, from the biological point of view It is effective to keep the lobsters with rubble angles.