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    • Article

      Effect of substrate types on fecundity and nauplii production of ablated Penaeus monodon Fabricius. 

      RA Pudadera, JH Primavera & E Borlongan - The Philippine Journal of Science, 1980 - Science and Technology Information Institute, Department of Science and Technology
      The survival, spawning, fecundity, and nauplii production of ablated Penaeus monodon females reared in flow-through broodstock tanks with white coralline and black sand substrates for 62 days, were assessed. Prawns exposed to the white coralline substrate consistently produced eggs with significantly higher (P - 0.05) average hatching rates and total nauplii production than those exposed to the black sand substrate. No differences were observed in the fecundity, spawning and survival rates in both treatments. It was observed that nightly sampling of ablated females during experiment 2 produced a higher number of spawning (48) and total number of nauplii produced (6.8 milion) compared to twice weekly sampling in experiment I (29 spawnings and 3.0 million nauplii) for the white substrate.
    • Article

      Effects of different sex ratios on maturation, fecundity and hatching rates of ablated Penaeus monodon wild stock. 

      RA Pudadera, JH Primavera & ATG Young - Fisheries Research Journal of the Philippines, 1980 - Fisheries Research Society of the Philippines
      The minimum number of males per female that would still ensure high maturation, fecundity and hatching rates in Penaeus monodon broodstock, is determined. Wild stock P. monodon were stocked in 4 m diameter circular tanks at different sex ratios (0:1, 1:1, 1:2 and 1:4 male to female) for a duration of 55 days. All females were ablated on one eyestalk. Males remained unablated. The 1 male: 2 females ratio is recommended on the basis of highest percentage of first, second and third spawners, total and average fecundity. In the all-female treatment (0:1 ratio), 19.65% of the females spawned, but the 3.3 million eggs produced were not fertilized, resulting in a 0% hatching rate.