Photo credit: David Kawahigashi (Thailand – David Kawahigashi – Vannamei101)
Review: Abdel Rahman El Gamal (Founder of the website)
The inserted photos were taken in a Thai shrimp facility and shows the gonadal development for a female of white shrimp (Litopenaeus vannaemai) which is carried out. In this particular photo the assessment of the gonadal development is done prior to the ablation of eyestalk which is practiced to stimulate the female shrimp to develop mature ovaries and spawn within as little as 3 to 10 days after the ablation.
In general, breeders classify the ovarian development of shrimp females into five stages as follows:
Stage: I: Immature (ovarian lobes translucent and smaller in diameter than the gut)
Stage II: Developing (ovarian lobes opaque, pale yellow-colored and with a diameter similar to that of the gut)
Stage III: Advanced (Ovarian lobes yellowish and larger in diameter than the gut)
Stage IV: Fully mature (ovarian lobes occupying entire part of the cepahalothorax cavity, strong lemon yellow color
Stage V: Spawned (lobes flaccid and convoluted with ova remains)
In order to check the stage of ovarian development, examined females are exposed to either sunlight or to strong –preferably waterproof- flashlight.
The females shown in the inserted photos are gravid females with highly developed, stage IV ovaries
