Detailed Explanation of Key Points and Methods for Mantis Shrimp Farming

People in different regions of China call the mantis shrimp by different names, such as: mantis shrimp, shrimp crawler, crawling shrimp, shrimp tiger, belt shrimp, shrimp grandma, shrimp grandpa, urinating shrimp, pee shrimp, piss shrimp, shrimp dog bullet, bullet shrimp, fortune shrimp, pipa shrimp, hualai worm, shrimp skin bullet worm, silkworm shrimp, shrimp bucai, water scorpion, mantis shrimp. In places such as Penglai Dajijia it is also called “official hat shrimp”, named because its tail looks like an official's black gauze cap when turned upside down.

Daily Management of Mantis Shrimp

During the rearing period, pond patrols are essential work, checking the water intake and drainage, the activity and feeding of the mantis shrimp, and the water quality, especially the release of larvae. Once the broodstock mantis shrimp are found to have released pseudozoea larvae, the larvae are collected into the nursery pond for rearing.

Broodstock mantis shrimp rearing refers to the rearing process in which female mantis shrimp that have already mated and whose ovaries have matured, or female mantis shrimp whose ovaries have developed but are not yet mature, are placed in a dedicated rearing pond for culture so that their gonads mature, they spawn, brood the eggs and hatch them, until the pseudozoea larvae hatch out. Their maturation promotion and egg brooding and hatching are carried out in the rearing pond, which has environmental conditions suitable for the mantis shrimp, so the maturation promotion effect is good, the egg-brooding rate is high, and the hatching rate is also high.

The purpose of broodstock mantis shrimp rearing is to make the ovarian development of the mantis shrimp basically synchronized, with spawning and larval release neat and orderly, so that a relatively large number of pseudozoea larvae can be obtained, forming a certain production scale. There are 2 types of broodstock mantis shrimp rearing ponds: one is the indoor pond, and the other is the outdoor pond. Indoor ponds are generally cement ponds, and outdoor ponds are earthen ponds. Broodstock mantis shrimp rearing should pay special attention to water quality management, bait management and daily management.

Water Quality Management

Keep the dissolved oxygen in the water body above 5ml/L, change 1/4 to 1/3 of the water daily, and keep the transparency at 30 to 50 cm. The mantis shrimp is a poikilothermic, ferocious crustacean, and its growth, development and life activities are directly affected by the ambient water temperature. The water temperature of its living area is roughly 6 to 31°C, with the optimum temperature at 20 to 27°C, and it is a eurythermal species.

Under laboratory conditions, when the mantis shrimp is moved directly from 17°C into seawater at 5°C, its body immediately arches up, and after slowly straightening it falls into coma. When it is moved into seawater at 33°C, the mantis shrimp first darts up and down, then falls sideways at the bottom, with only the swimming legs able to move, and falls into coma after 3 minutes. Therefore its temperature tolerance range is considered to be 5 to 33°C.

When the water temperature changes gradually, the temperature tolerance range increases. During broodstock mantis shrimp rearing, special attention should be paid to temperature differences; generally speaking, during rearing, the water temperature should be controlled at 20 to 30°C. Water temperature is an inhibitory factor for the gonadal development of the mantis shrimp, and within the suitable temperature range, the higher the water temperature, the faster the development. If the summer temperature is too high, the water level can be increased to prevent the water temperature from being too high and affecting the broodstock mantis shrimp's egg brooding and larval hatching, or even causing death. At a water temperature of 25 to 30°C, it takes 7 to 15 days for the egg to go from fertilization to hatching of the larva.

Bait Management

The mantis shrimp can feed on fish, shrimp and shellfish, but live small shellfish are best, as they can avoid polluting the water quality. The bait should be in small pieces and scattered evenly so as to facilitate feeding, improve the bait utilization rate and reduce mutual killing due to competition for food.

According to the mantis shrimp's habit of hiding by day and coming out at night, feeding once each evening is sufficient, with the feeding amount being 5% to 20% of the broodstock mantis shrimp's weight, and increased or decreased appropriately according to the broodstock mantis shrimp's egg-brooding situation, water temperature, weather conditions, and the type and quality of the bait.

In the early stage of rearing, the feeding amount can be appropriately increased to provide sufficient nutrition for gonadal development. Broodstock mantis shrimp bore into holes when brooding eggs and basically do not feed, so when it is estimated that most broodstock mantis shrimp are brooding eggs, the feeding amount should be reduced. In addition, after broodstock mantis shrimp hatch their larvae, they shift to growth, their food intake increases greatly, and they also disturb other egg-brooding mantis shrimp, so it is best to trap them out of the pond with cage nets and the like.

Selection and Transport of Mantis Shrimp

For broodstock mantis shrimp, female mantis shrimp that have mated can be selected from artificial farming or natural sea areas.

Although they can reproduce at a body length of over 8 cm, in order to ensure quality and increase the egg-brooding amount, it is advisable to select those with a body length of over 11 cm and a body weight of over 30 g. In addition, when purchasing broodstock mantis shrimp, note that the time the mantis shrimp has been out of water should be short, the degree of gonadal development should be relatively good, the body should be robust, the appendages complete, with no wounds, strong vitality, bright body color, and sensitive response to external stimuli. After purchase, the broodstock mantis shrimp should be transported to the nursery factory as soon as possible and placed in ponds for temporary rearing and cultivation.

Transport methods include live-fish boat transport, nylon bag oxygenated transport, dry moisture-retaining transport and canvas bucket transport with water, etc. The broodstock mantis shrimp are first bathed in 200×10⁻⁶ formaldehyde for 3 minutes, then those with complete appendages and lively behavior are selected and placed in a previously disinfected cement pond (9 m×4 m×1.2 m), filtered fresh seawater is added, and aeration is provided, so that they recover their vitality and are temporarily reared. The water temperature in the broodstock mantis shrimp temporary rearing pond should preferably be 1 to 2°C higher than that of the sea area for the first 1 to 3 days. If the water temperature is raised too quickly or too high, it is easy to cause the broodstock mantis shrimp to give birth prematurely or miscarry.

Afterwards, the temperature is raised at a rate of 0.5 to 1.0°C/day to 21 to 22°C for temporary rearing for 20 to 30 days, feeding a small amount of fresh sandworms, small shrimp, clam meat and the like, so as to further fatten the gonads.

Although the female basically stops feeding during the reproductive season and almost all stomachs are empty, when at a temperature of 22°C the gonadosomatic index reaches more than 14%, the eggs in the spawned egg mass are clear and basically clumped, which means they are mature eggs.

I think everyone is very familiar with the mantis shrimp, and many people in daily life like to eat mantis shrimp. Compared with lobster, the mantis shrimp has more meat and is more delicious, so the mantis shrimp lives in the sea and is generally more common in the north.