Spawning
behaviour of Penaeus (Fenneropenaeus) merguiensis de
Man and the effect of light intensity on spawning
T. Hoang, S.Y. Lee, C.P. Keenan, G.E.
Marsden-2002
Aquaculture
Research, 33(5):
351-358
Abstract:
An experiment was conducted to
investigate the effect of light intensity just prior to and during spawning
of Penaeus (Fenneropenaeus) merguiensis de Man in the laboratory.
Neither the presence of light nor light intensity (0, 10 and 1100 lux) had a
significant effect on the spawning process or hatching rate in P.
merguiensis. Difference in the percentage of spawners, percentage of
incomplete spawning, fecundity and hatching rate were all insignificant
(P>0.05)
among the three light treatments. However, spawning was delayed (up to 21
min on average) under 1100 lux with a high percentage of incomplete spawning,
compared with the Control (0 lux). For the first time, spawning behaviour of
P. merguiensis was observed and fully described. The spawning process
can be divided into four phases: dormant, pre-spawning, spawning and
post-spawning by distinct behaviour of prawn broodstock. The dormant phase
was characterized by a quiescent and non-feeding period, whereas movement of
prawn broodstock was active during the pre-spawning and post-spawning
phases. Depending on the individual, spawning was completed within 3-5 min. Prawns often stayed still on the water surface during spawning with
occasional manoeuvres to change the position. After a short rest at the
termination of the spawning phase, prawn broodstock re-exhibited active
movement as in the pre-spawning phase, but showing conspicuous care to the
deposited eggs. The role of light in controlling ovarian development and
spawning, and the behaviour of prawn broodstock in relation to maximizing
fertilization rate are discussed.
(Bribie Island Aquaculture Research
Centre, Queensland Department of Primary Industries, PO Box 2066, Bribie
Island, Queensland 4507, Australia. E-mail: hoangt@dpi.qld.gov.au)