K. Shioda et al., CONTROL OF WATER-QUALITY IN THE CULTURE OF EARLY-STAGE PHYLLOSOMAS OFPANULIRUS-JAPONICUS, Bulletin of marine science, 61(1), 1997, pp. 177-189
A method for culturing phyllosomas of spiny lobster is characterized b
y use of the microalga Nannochloropsis oculata in the phyllosoma cultu
re water. The method seems to be most effective during the microalgae
growth phase due to the water purification activity of the microalgae.
Ln contrast, accumulation of microalgae during the declining phase ma
y cause a deterioration of water quality. The period necessary between
changes of the culture medium was determined for early stage phylloso
mas of Panulirus japonicus. The culture water was initially light gree
n. The color gradually deepened and changed to yellow. The amount of c
hlorophyll a was relatively stable. Carotenoids/Chlorophyll a ratio wa
s initially 0.30 and increased to 0.50 over about 2 wks. Chemical oxyg
en demand (COD) steadily increased to 1.2 - 1.5 ppm after 14 - 19 d. T
he rate of COD increase was lower in cultures which had higher microal
gae growth rates. The initial concentration of ammonia-N, about 0.4 pp
m, at the addition of the microalgae, which was removed within a few d
ays. The bacterial number ranged between 4 x 10(3) and 3 x 10(4), and
no significant effect due to bacteria was observed. Survival rate of p
hyllosomas was best when the culture water was changed every 13-14 d a
t initial concentration of Nannochloropsis at one million cells ml(-1)
and allowed to remain unchanged for 34 d.