Amphioctopus fangsiao

This species occurs in the Philippine Sea, the northwest Pacific and off the coast of Japan (Osaka Bay).

The lifespan of this species is approximately a year, typically spawning in the spring and growing linearly after spawning.[10] In Haizhou Bay in the Yellow Sea, smaller individuals of A. fangsiao tend to be found closer to the shore in the spring and even closer during the summer, while larger individuals tend to be distributed further away from the shore.[10]

• 
  Closeup of suckers
• 
  Hiding in shell

A. fangsiao holds an embryonic temperature threshold in which growth accelerates at 21–24 °C (70–75 °F). In three days after gestation the octopus is typically still gastrulating. On day 5, the embryo completes their first inversion and between days 15–21 after gestation, the octopus embryo exhibit chromatophores and black eyes.[5] The embryos complete their second inversion between days 25–31.[5] Octopus embryos develop logarithmically faster with increase in temperature; those embryos who develop at a temperature of 24 °C (75 °F) go through 0.83 embryonic stages per day on average while embryos that develop at a temperature between 18 and 21 °C (64 and 70 °F) go through 0.67 embryonic stages per day on average.[5] The octopuses that had a smaller embryo but larger yolk volume tended to hatch at 24 °C (75 °F).[5]

Like many other species of cephalopods, A. fangsiao is not safe from infection. As of 2021, there is not much information on the protozoan parasites that infect this species among other species of cephalopods native to the Pacific Ocean. It is known that is that these parasites belong to the genus Aggregata and are responsible for the infections that have led to the death of many A. fangsiao in a culture facility in China.[11] Infection in A. fangsiao was also found from the genus Octopicola.[11]

These octopuses are generally found along the shores of China, and are relatively highly genetic diverse in haplotype diversity, especially in the Zhanjiang province while the lowest haplotype diversity is seen in the Qingdao province. They also have low nucleotide diversity.[7] There is more genetic variation among the population of A. fansgsiao than there are within the population of A. fangsiao.[7]

Two groups were defined by their genetic similarities and by region: A. fangsiao in the northern shore, including Dalian, Yantai, Qingdao, and Nantong provinces, were more similar among each other while the A. fangsiao in the southern shore, including Wenzhou, Xiamen, Dongshan, and Huizhou provinces, were more genetically similar each other.[7] A haplotype network analysis showed that all the octopuses in the northern provinces shared a haplotype with each other using several mitochondrial gene markers (ATPase 6, ND2, and ND5), while the octopuses in the southern provinces shared different haplotypes with each gene marker; in all gene markers, the northern and southern province octopuses did not share any haplotypes with each other.[7]

In Korea, Amphioctopus fangsiao is called jukkumi (주꾸미) or jjukkumi (쭈꾸미) and is often stir-fried in spicy gochujang-based sauce.[13][14]

• 
  Jukkumi-bokkeum (stir-fried)
• 
  Jukkumi-gui (grilled)
• 
  Seafood skewers sold in South Korea, including jju-kkochi (webfoot octopus skewers)

• Norman M.D. & Hochberg F.G. (2005) The current state of Octopus taxonomy. Phuket Marine Biological Center Research Bulletin 66:127–154.
• Furuya, H. (2006). Three new species of dicyemid mesozoans (Phylum Dicyemida) from Amphioctopus fangsiao (Mollusca: Cephalopoda), with comments on the occurrence patterns of dicyemids. Zoological Science 23: 105–119.

• Media related to Amphioctopus fangsiao at Wikimedia Commons
• DNA information for Amphioctopus fangsiao Archived 5 March 2016 at the Wayback Machine