What water plants are best for feeding crabs? Recommended correct feeding methods worth saving

Anyone who raises crabs has probably heard the saying “to raise crabs you must raise the water, and to raise the water you must plant grass”, which is enough to show the importance of water plants in crab farming. So what water plants are best for feeding crabs? How should you feed them to be most correct?

1. What water plants are best for feeding crabs

1. Hydrilla verticillata

Hydrilla verticillata likes high temperatures, has good adaptability, a long growth period and strong regeneration, and river crabs like to eat it, making it suitable for planting in crab ponds and large water bodies with sufficient light. Hydrilla verticillata has extremely strong vitality; after being pinched off by river crabs, the broken segments can all take root on their own, so it will not cause water quality to deteriorate.

2. Elodea

Elodea sprouts early and grows quickly. Especially in the early stage when other water plants have not yet grown, only Elodea can provide an ideal place for river crabs to grow, rest, molt and avoid enemies. However, Elodea is not tolerant of high temperatures and grows densely. When the water temperature reaches 30 degrees C, growth basically stops, and it easily fouls the water. The planting area should be controlled within 20 percent, and it is generally planted as a transitional water plant.

3. Hornwort

Hornwort is tolerant of high temperatures, is liked by crabs and has strong regeneration, with obvious advantages. The drawback is that vigorous growth easily causes water fouling. Therefore, hornwort is more suitable for planting in large water bodies. When hornwort grows vigorously, it should be thinned manually to avoid it becoming too dense, affecting photosynthesis and causing phenomena such as dead grass and fouled water.

4. Vallisneria

Vallisneria has the advantages of being liked by crabs, not fouling the water and tolerating high temperatures. The drawback is that it is easily destroyed. Especially in the high-temperature summer period, the season when river crabs are fed and switch food, if protection is neglected even slightly, the losses will be very severe. In some crab ponds mainly planted with Vallisneria, in less than a week during the high-temperature period, crab farmers do not even have time to remove the grass before the Vallisneria is completely pinched away by the crabs. According to estimates, the cost of removing grass in crab ponds mainly planted with Vallisneria is 70-120 yuan per mu. If the grass is not removed in time, it causes water quality to deteriorate, or even become foul, producing “stinky green algae”, triggering mass death of river crabs, so when feeding, the grass must be removed in time to avoid losses.

2. How to feed water plants to be most correct

1. Raising crabs in ponds and rice fields

For raising crabs in ponds and rice fields, Elodea, Vallisneria and Hydrilla verticillata can be chosen. For the early growth, resting, molting and enemy-avoiding places of river crabs, Elodea can be used to build them, because Elodea sprouts early and grows quickly and can serve as a transitional water plant for spring and summer. Before the high-temperature period arrives, in order to avoid Elodea dying and rotting, deteriorating and fouling the water and killing crabs, the tops of Elodea should be cut off, keeping only about 10 cm above the roots. The early proportion of Elodea should be controlled at about 20 percent to facilitate gradual elimination during the high-temperature period. Vallisneria is liked by crabs and can serve as a “snack” for river crabs to ensure sufficient plant-based feed for river crabs. The proportion can be controlled at 20 percent-30 percent, and in order to provide river crabs with fresh and tasty “snacks” over the long term, and to avoid it being destroyed by river crabs all at once, Vallisneria can be sown in stages and batches, staggering the growth periods. Then, taking advantage of the characteristics of Hydrilla verticillata, which likes high temperatures, is liked by crabs and is not easily destroyed, pond and rice field farming models can mainly plant it. The coverage rate of Hydrilla verticillata should be controlled at 40 percent-50 percent. In summer, the places for heat avoidance, resting, molting and enemy avoidance for river crabs in the middle and late growth stages can be replaced with Hydrilla verticillata.

2. Raising crabs in rivers, ditches and lakes

For raising crabs in rivers, ditches and lakes, the choice of water plants is mainly hornwort or Hydrilla verticillata, supplemented by Elodea and Vallisneria. Hornwort or Hydrilla verticillata is mostly planted at the junction of shallow and deep water, and the total proportion of water plants should be controlled at 40 percent-50 percent. Vallisneria is mostly planted in shallow water, with the proportion controlled at about 10 percent. For “bare water ponds”, if they are to be cultivated into crab ponds in the same year, some Elodea should be planted in the early stage, with the coverage rate controlled at about 20 percent. To avoid Elodea dying and rotting, deteriorating and fouling the water and killing crabs, the tops can be cut off during the high-temperature period, leaving only 10 cm above the roots. No matter which water plant it is, it is best not to emerge above the water surface or affect wind and waves.

Cultivating high-quality water plants is the major precondition for farming large-size, high-quality river crabs, so if farmers want to improve the quality of the crabs they raise, the choice and feeding methods of water plants must not be careless.