Look at body color. Good fish fry have the same group of pigments, and their body color is fresh; poor fish fry have different pigment groups and their body color is slightly white.
Second look at the composition of groups. Good fry were tidy, plump, smooth and not muddy, swimming and lively; poor fry were smaller, ranging in size, and dragging mud.
Three to see the ability to move. Put the hand or wooden stick into the middle of the seedling bowl and the seedling dish to make the fry frightened. The good fry quickly travels around; the poor fry is unresponsive.
Fourth, look at the counter-current flow. Stir the fish body with your hands or a wooden stick to swirl the water. The good fry can swim against the water along the edge; the poor fry is caught in the whirlpool and is unable to struggle. If the fish fry in the white porcelain basin, let the wind blow the water, so that the fry can swim against the wind; poor fry can not.
Five look at the ability to struggle. Put the fry into the white porcelain dish and drain the water. The fry will be struggling and the head and tail will be bent into a round shape. The poor fry will not be able to struggle and only tremble.
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