User:Susennac/Amphioctopus fangsiao

Amphioctopus fangsiao, called webfoot octopus, is a species of octopus, a cephalopod belonging to the genus Amphioctopus. It is found in the Pacific Ocean, including off the coasts of New Zealand. The Amphioctopus fangsiao octopus can be found in the Yellow Sea and surrounding Chinese shores. It is also one of the main species involved in commercial fishing.

Individuals of A. fangsiao share genetic similarities by region are distributed throughout the Yellow Sea by size.

Distribution
The lifespan of this species is approximately a year, typically spawning in the spring and growing linearly after spawning. In Haizhou Bay in the Yellow Sea, smaller individuals of A. fangsiao tend to be distributed 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.

Structure
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Embryonic Development
A. fangsiao holds an embryonic temperature threshold in which growth accelerates at 21-24°C. 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. The embryos complete their second inversion between days 25-31. Octopus embryos develop logarithmically faster with increase in temperature; those embryos who develop at a temperature of 24°C go through 0.83 embryonic stages per day on average while embryos that develop at a temperature between 18°C and 21°C go through 0.67 embryonic stages per day on average. The octopuses that had a smaller embryo but larger yolk volume tended to hatch at 24°C.

Abnormal morphologies
The embryos that grew at 27°C were not able to hatch due to accelerated growth which caused eggs to be more swollen than eggs developing at lower temperatures; this accelerated growth caused the chorion to break and the embryo to hatch prematurely. While the eggs grown at 21°C were ovular in shape as normal, the eggs grown at 24°C were malformed. The embryos grown in 24°C conditions also exhibited red eyes at 2 days after gestation.

Feeding Habits
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Diseases
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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. There is more genetic variation among the population of A. fansgsiao than there are within the population of A. fangsiao. 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. A haplotype network analysis showed that all the octopuses in the northern provinces shared Haplotype 1 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.

Culinary Use
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