247
14 Sepiella japonica
Low aeration rate can be carried out in the earlier period, which should be intensified in the later period.
At the initial period, the culture density is maintained at 1,000–1,500 individuals m
−3
, which should be reduced to 300–500 individuals m
−3
once the ML reaches
15–20 mm. The crowding and insufficient feed may cause the juveniles to fight for
feed or even eat each other.
Thirty to forty days after hatching, the ML of the juvenile S� japonica increases
to 20 mm and total wet weight reaches 2–3 g.
14.5 Ongrowing
When the ML of the juveniles reaches 20 mm or when the hatchlings start demersal
life, they can be transferred to indoor pools, outdoor ponds as well as cages for
further growing.
14.5.1 Indoor Ongrowing
Indoor round pools of 10 m
2
are used. Indoor ongrowing can guarantee the physical
and chemical conditions of the seawater and allows fine management. The pools
should be covered with black cloth sheeting, and water inside it should be flowing
constantly. There should be fresh air in the room and optimal quality water with appropriate DO in the pools. The room temperature should be controlled at 15–20 °C.
There should be good drainage, the noise from the pump should be low and the
feeding operation should be convenient to conduct. The main parameters for the
ongrowing period are as follows:
Feed There must be change of feed at the beginning of this period. Small shrimps
(e.g. N� awatschensis, Acetes sp.), Artemia urmiana and fish ( P� parva) captured
from the wild can be used. Feeding should be done two to three times a day,
with the quantity equal to 8–10 % of the main total body weight of juveniles.
Gradually, inexpensive fresh fish ( Ammodytes personatus) and shellfish ( Ruditapes philippinarum) can be introduced as interim or transition feed, and then
decreased gradually through the middle and later stage. Finally, frozen fish ( S�
lemuru) and shellfish ( S� constricta) muscles will become main diet for adult
cuttlefishes.
Water temperature and salinity The temperature is controlled at 10–28 °C, salinity at 20–32 psu, and the water depth should be at least 0.5 m.
Culture density It depends on the size of the individuals. For the juvenile with
12–20 mm ML, the density ranges from 600 to 800 individuals m
−3
, whilst with ML
over 60 mm, less than 100 individuals m
−3
(Fig. 14.4a).
14 Sepiella japonica
Low aeration rate can be carried out in the earlier period, which should be intensified in the later period.
At the initial period, the culture density is maintained at 1,000–1,500 individuals m
−3
, which should be reduced to 300–500 individuals m
−3
once the ML reaches
15–20 mm. The crowding and insufficient feed may cause the juveniles to fight for
feed or even eat each other.
Thirty to forty days after hatching, the ML of the juvenile S� japonica increases
to 20 mm and total wet weight reaches 2–3 g.
14.5 Ongrowing
When the ML of the juveniles reaches 20 mm or when the hatchlings start demersal
life, they can be transferred to indoor pools, outdoor ponds as well as cages for
further growing.
14.5.1 Indoor Ongrowing
Indoor round pools of 10 m
2
are used. Indoor ongrowing can guarantee the physical
and chemical conditions of the seawater and allows fine management. The pools
should be covered with black cloth sheeting, and water inside it should be flowing
constantly. There should be fresh air in the room and optimal quality water with appropriate DO in the pools. The room temperature should be controlled at 15–20 °C.
There should be good drainage, the noise from the pump should be low and the
feeding operation should be convenient to conduct. The main parameters for the
ongrowing period are as follows:
Feed There must be change of feed at the beginning of this period. Small shrimps
(e.g. N� awatschensis, Acetes sp.), Artemia urmiana and fish ( P� parva) captured
from the wild can be used. Feeding should be done two to three times a day,
with the quantity equal to 8–10 % of the main total body weight of juveniles.
Gradually, inexpensive fresh fish ( Ammodytes personatus) and shellfish ( Ruditapes philippinarum) can be introduced as interim or transition feed, and then
decreased gradually through the middle and later stage. Finally, frozen fish ( S�
lemuru) and shellfish ( S� constricta) muscles will become main diet for adult
cuttlefishes.
Water temperature and salinity The temperature is controlled at 10–28 °C, salinity at 20–32 psu, and the water depth should be at least 0.5 m.
Culture density It depends on the size of the individuals. For the juvenile with
12–20 mm ML, the density ranges from 600 to 800 individuals m
−3
, whilst with ML
over 60 mm, less than 100 individuals m
−3
(Fig. 14.4a).