PHASA FACTOR INFLUENCING MATURATION AND SPAWNING OF THE PRAWN PENAEUS JAPONICUS (Bate)

PHASA FACTOR INFLUENCING MATURATION AND
SPAWNING OF THE PRAWN PENAEUS JAPONICUS (Bate)
By
N. F. ABD EI-HAMID*
·k National Institute of Oceanography and Fisheries, Alexandria – Egypt.
Key words: Penaeus japonicus, eyestalk ablation, pH induced maturation.
ABSTRACT
Unilateral eyestalk extirpation in females of Penaeus japonicus
(Bate) is sufficient to induce maturation and spawning in 3-5 days time
when the pH ofthe maturation ranks was maintained at a level similar to
that of the sea water (between 8.2 and 8.4) by daily addition ofIN
sodium carbonate. But eye-ablatedfemales kept in tanks where the pH
was allowed to fall below 7. 9 did not attain full ovarian development
and no spawning was obtained.