Ovarian maturation of the
banana prawn, Penaeus merguiensis de Man under different light
intensities
T. Hoang, S.Y. Lee, C.P. Keenan, G.E. Marsden-2002
Aquaculture, 208(1-2): 159-168
Abstract:
The effect of light intensity on ovarian maturation
and spawning of unablated female Penaeus merguiensis was investigated
in a 4-week experiment. The experiment had two different light intensity
treatments: BRIGHT (1100 lx) and DIM (2 lx). At starting time, there were
four groups of broodstock with four different ovarian maturation stages (II,
III, IV and V) in each treatment. Results showed that light intensity plays
an important role in controlling ovarian maturation of prawns, especially at
the later stages (stages III and IV). Bright light showed an inhibitory
effect, whereas dim light favoured ovarian maturation and spawning. Ovarian
regression occurred in most stage III and stage IV prawns kept under bright
light, while prawns at the same stages developed their ovaries further and
spawned under dim light. Proportion of spawners (12.5%), mean number of
spawns per prawn (0.12) and mean fecundity (87,300) of prawns were
significantly lower (P<0.05) in the BRIGHT treatment, compared to
the DIM treatment. Under light intensity of 2 lx, 41.7% of prawns spawned,
producing 0.5 spawn per prawn on average with a mean fecundity of 117,300.
The results also suggest that the sensitivity of broodstock to light
increased from stages II to IV of ovarian maturation, while there were some
evidence of light adaptation in stage V broodstock. This study confirmed
multiple spawning of unablated P. merguiensis for the first time.
Rematuration period was short (6-7 days).
(School of Environmental and Applied Sciences,
Griffith University Gold Coast, PMB 50 GCMC, Queensland 9726, Australia,
Tel.: +61-7-3400-2020; fax: +61-7-3408-3535, e-mail: hoangt@dpi.qld.gov.au)