Sometimes, the coloration is not distinct. The degree of maturity also can be determined as follows: with the left hand, gently hold the shrimp at the anterior part of the carapace; to calm the animal down, the shrimp's eyes should be hidden within the palm. With the right hand, hold the abdomen of the shrimp, then slowly and gently bend the shrimp between the carapace and the abdomen. Check the median lobe of the ovary through the thin membrane. A well-developed gonad appears as a dark and broad lobe and the ova have a granular texture (Yang, 1975).

Ovarian maturity also may be checked by holding the shrimp against a well-lighted background and looking through the dorsal part of the abdomen. Observe the shape of the posterior lobe of the ovary. Usually, a developing ovary has a narrow, tapering, light-colored lobe. A ripe or well-matured ovary has a wide and dark lobe with distinct margins. Certain species or individuals within a species, in addition to having dark and wide lobes, may have noticeable, nearly oblong bulges in the ovarian lobe, especially at the first abdominal somite. The spent ovary is broad but appears empty and is translucent (Yang, 1975).

Sometimes, even after careful scrutiny for ovarian maturation, where the selected ovigerous females have met the above requirements, some individuals will not spawn after being placed in the culture tank. This is probably related to some kind of physiological stress (Yang, 1975).