Quality of hatchery shrimp is a very important factor that can influence yield of the harvest as well as can increase resistance of shrimp against diseases.
Criteria for selecting hatchery shrimp:
– They must be same size and around 12mm.
– Their abdomen has 6 sections; if these sections are long, shrimp will grow fast. Healthy shrimps must have tail and beard shaped V, and two beard close together as V angle.
– Legs near tail should open widely when swimming; distance between 4 legs should be as far as possible.
– No fungi, bacteria or protozoa on legs, abdomen, tail, shell and gill of shrimp. These objects will make shrimp asphyxiated and unable to molt shell.
– Bright color, thin shell, grey-black color or black color, balance between head and body.
– When stirring water, shrimps will not be drifted in twist but swim opposite direction. If there are 10 of 200 shrimp drifted in twist, it means the hatchery shrimps weak.
– Test with phormon: use 1ml phormon with 10 liters of water; if 5 of 150 shrimps die, this is healthy hatchery shrimps.
– Before releasing shrimp to pond, must bath shrimp to ensure they are free from bacteria. Or still feed shrimp in hatchery pond in 15-20 days, then refine again before start to feed in soil pond.
– Best selection is shrimps like to swim opposite direction to twist.
Source: Tiep Phat Aquatic Medicine