423
22 Octopus minor
Province), for the past 4 years. The detailed effect of resource restoration is being
evaluated.
22.7 Trends in Research and Industrial Level
One of the main subjects studied in China at present is to obtain an indoor method to
develop the rearing process of O� minor all year round. The researches on biological
zero temperature and effective accumulated temperature for embryonic development of O� minor have been carried out under artificial conditions (Liu 2013). The
embryonic development could stop when the temperature decreased below the biological zero (3.79 °C) and the embryo could tolerate down to approximately 0 °C.
Once above the biological zero temperature, the embryonic development could
resume and also hatch as usual. These recent results indicate that the incubation
of O� minor will be feasible indoors all year round in the north of China. Though
artificial culture can greatly enhance the hatching and the survival rate, the number
of spawned eggs per O� minor female is only 9–125, and besides this the embryonic
development lasts for at least 70 days (Qian et al. 2013). It is obvious that these results restrict severely the industrial culture of O� minor due to such a low fecundity
and long embryonic development period. Certainly, optimization of feed formulation is also another key factor for its commercial culture which still requires further
research.
The artificial nursery of O� minor in the Moon Lake National Aquatic Resources
Conservation Area, China, has been working since 2009, and the releasing of hatchery-produced octopus has become the main approach of resource protection and
stock enhancement programmes.
22.8 Conclusions
As an important economic cephalopod, O� minor has been cultured in the northeast
coastal waters of China in recent years. The whole culture process includes broodstock capture, acclimatization to captivity, spawning, hatchling culture, ongrowing
and overwintering culture and harvesting. The main conclusions are the following:
1. Eggs are spawned at the artificial substratum, and females are responsible for
protecting the eggs (Fig. 22.7a). The number of spawned eggs ranges from 9 to
125 under the artificial conditions. The embryonic development lasts for 72–89
days before hatching under the conditions of a seawater temperature of 21–25 °C
and a salinity of 28–31 psu. The mantle length and total length of new hatchlings
range from 8.5 to 11.5 mm and from 25 to 31 mm, respectively.
2. Hatchlings are benthic. The shelters provided are ceramic pots of 8–12 mm inner
diameter or 10-mm-diameter PVC tubes. Cladocerans, copepods and enriched
22 Octopus minor
Province), for the past 4 years. The detailed effect of resource restoration is being
evaluated.
22.7 Trends in Research and Industrial Level
One of the main subjects studied in China at present is to obtain an indoor method to
develop the rearing process of O� minor all year round. The researches on biological
zero temperature and effective accumulated temperature for embryonic development of O� minor have been carried out under artificial conditions (Liu 2013). The
embryonic development could stop when the temperature decreased below the biological zero (3.79 °C) and the embryo could tolerate down to approximately 0 °C.
Once above the biological zero temperature, the embryonic development could
resume and also hatch as usual. These recent results indicate that the incubation
of O� minor will be feasible indoors all year round in the north of China. Though
artificial culture can greatly enhance the hatching and the survival rate, the number
of spawned eggs per O� minor female is only 9–125, and besides this the embryonic
development lasts for at least 70 days (Qian et al. 2013). It is obvious that these results restrict severely the industrial culture of O� minor due to such a low fecundity
and long embryonic development period. Certainly, optimization of feed formulation is also another key factor for its commercial culture which still requires further
research.
The artificial nursery of O� minor in the Moon Lake National Aquatic Resources
Conservation Area, China, has been working since 2009, and the releasing of hatchery-produced octopus has become the main approach of resource protection and
stock enhancement programmes.
22.8 Conclusions
As an important economic cephalopod, O� minor has been cultured in the northeast
coastal waters of China in recent years. The whole culture process includes broodstock capture, acclimatization to captivity, spawning, hatchling culture, ongrowing
and overwintering culture and harvesting. The main conclusions are the following:
1. Eggs are spawned at the artificial substratum, and females are responsible for
protecting the eggs (Fig. 22.7a). The number of spawned eggs ranges from 9 to
125 under the artificial conditions. The embryonic development lasts for 72–89
days before hatching under the conditions of a seawater temperature of 21–25 °C
and a salinity of 28–31 psu. The mantle length and total length of new hatchlings
range from 8.5 to 11.5 mm and from 25 to 31 mm, respectively.
2. Hatchlings are benthic. The shelters provided are ceramic pots of 8–12 mm inner
diameter or 10-mm-diameter PVC tubes. Cladocerans, copepods and enriched