250
X.-D. Zheng et al.
with reversed whisker, can be used to capture them. Firstly, baits (fresh fish or
shrimp) are deposited into them, and then the traps are hung into the water. The
traps will be lifted when there are a sufficient number of adult cuttlefishes. It is
not advisable to take them out of the traps by hands; instead, they should be taken
out with big spoons with water inside. However, when water temperature is below
15 °C, S� japonica is not active and the trap capture is not feasible; instead, purse
seine or draining-out-the-pond method can be adopted.
14.7 Trends in Research and Industrial Level
Optimization of the feed supply is a key to commercial culture which still requires
further research. Furthermore, the production of artificial feed is still a scientific
blank at the moment.
The culture of S� japonica has not caused loss of meat quality so far, and cultured
production can fully substitute wild products to be an ideal healthy food (Chang
et al. 2008). But the mean size of the stocks reared indoors is 20 % smaller than the
wild ones. Whether this is caused by genetic degeneration, the artificial environment or culture technique is still unknown. S� japonica spends at least 6–8 months
to reach sexual maturity in the wild; however, under the artificial environment,
it requires only 3–4 months. The authors suggest that early sexual maturity and
shorter growth period should be the main reasons why the cultured individuals are
significantly smaller than their wild counterparts. Although the maturation phase of
the species has been lengthened from 3–4 months to 6 months by adjusting the light
intensity indoors, related problems still have to be solved. It is worth noting that the
wild resource restocking of the species has been achieved by releasing of artificial
hatchlings in recent years (Wu et al. 2010).
14.8 Conclusions
The process of spineless cuttlefish culture includes broodstock capture, acclimatization to captivity, spawning, hatching, nursing, ongrowing and harvest. The main
conclusions are as follows:
1. In general, each wild female of S� japonica lays 1,000–2,000 eggs. Water temperature and salinity of hatching are 20–26 °C and 25.0–32.0 psu, respectively.
The hatching period is 17–26 days. Hatchlings are planktonic, and mean ML is
approximately 4 mm. The highest hatchling survival rate (83.3 %) is obtained
when initial feeding is based on cladoceran, copepods, shrimp or Artemia.
2. When the ML of juveniles reaches 20 mm or when the hatchlings start benthic
life, they can be transferred to indoor pools, outdoor ponds as well as cages for
growing. The survival rate from the juvenile to adult phase is about 60 %. The
X.-D. Zheng et al.
with reversed whisker, can be used to capture them. Firstly, baits (fresh fish or
shrimp) are deposited into them, and then the traps are hung into the water. The
traps will be lifted when there are a sufficient number of adult cuttlefishes. It is
not advisable to take them out of the traps by hands; instead, they should be taken
out with big spoons with water inside. However, when water temperature is below
15 °C, S� japonica is not active and the trap capture is not feasible; instead, purse
seine or draining-out-the-pond method can be adopted.
14.7 Trends in Research and Industrial Level
Optimization of the feed supply is a key to commercial culture which still requires
further research. Furthermore, the production of artificial feed is still a scientific
blank at the moment.
The culture of S� japonica has not caused loss of meat quality so far, and cultured
production can fully substitute wild products to be an ideal healthy food (Chang
et al. 2008). But the mean size of the stocks reared indoors is 20 % smaller than the
wild ones. Whether this is caused by genetic degeneration, the artificial environment or culture technique is still unknown. S� japonica spends at least 6–8 months
to reach sexual maturity in the wild; however, under the artificial environment,
it requires only 3–4 months. The authors suggest that early sexual maturity and
shorter growth period should be the main reasons why the cultured individuals are
significantly smaller than their wild counterparts. Although the maturation phase of
the species has been lengthened from 3–4 months to 6 months by adjusting the light
intensity indoors, related problems still have to be solved. It is worth noting that the
wild resource restocking of the species has been achieved by releasing of artificial
hatchlings in recent years (Wu et al. 2010).
14.8 Conclusions
The process of spineless cuttlefish culture includes broodstock capture, acclimatization to captivity, spawning, hatching, nursing, ongrowing and harvest. The main
conclusions are as follows:
1. In general, each wild female of S� japonica lays 1,000–2,000 eggs. Water temperature and salinity of hatching are 20–26 °C and 25.0–32.0 psu, respectively.
The hatching period is 17–26 days. Hatchlings are planktonic, and mean ML is
approximately 4 mm. The highest hatchling survival rate (83.3 %) is obtained
when initial feeding is based on cladoceran, copepods, shrimp or Artemia.
2. When the ML of juveniles reaches 20 mm or when the hatchlings start benthic
life, they can be transferred to indoor pools, outdoor ponds as well as cages for
growing. The survival rate from the juvenile to adult phase is about 60 %. The