Maturation and growth of ablated and unablated penaeus monodon
Aquaculture 32(3-4): 235-242
Both single eyestalk ablated and unablated P. monodon have been induced to spawn domestically under reduced light conditions. Ablated females developed their ovaries almost immediately while unablated females took 1-2.2 mo. or 2 or 3 molt cycles to develop and often never beyond ovarian stage 3. Ablated females spawned up to 4 times per molt cycle and unablated up to 3 times. Most of the spawns were 1st ones in the molt cycle from 36.4% for ablated females to 67% for the unablated ones. The average molt-cycle duration for unablated spawners (28 days) was slightly longer than for ablated females (26 days) but this was not statistically different. Molt-cycle duration increased with increasing female mass although correlation was poor (r = 0.38). Generally females smaller than 120 g gained mass, while females larger than 120 g lost mass. Suggestions to improve mass loss are given. A 1:1 male:female ratio did not appear to be adequate (unviable ova) so that this ratio could be increased or the male tank method of Beard and Wickins (1980) could be employed.