愛媛県今治で採取されたテナガダコOctopus minorの体形異常個体

2006年5月, 2007年4月と同6月に愛媛県今治漁業協同組合魚市場で体形が異常なテナガダコOctopus minorの雄3個体が採取された。通常雄は右第Ⅲ腕のみが交接腕であるが, 2006年の1個体はさらに左第Ⅲ腕も交接腕になっており, 奇形と思われた。また2007年の2個体は全体的に"水ぶくれ"状態であるが衰弱し, 特に腕部は水のような透明な液体を内包して萎縮状態であった。これは繁殖産卵を終えた死滅前の病理的な現象ではないかと思われた。

The three male freak minor octopus, Octopus minor were found out on Fish Market of Imabari Fisheries Cooperative, Ehime Prefecture, Japan. One of them was the octopus landed on May 25, 2006, which had two hectocotilized arms on both of the third right and left, though male octopus usually has only one hectocotilized arm on the third right arm. It was seemed to be arisen from the abnormal generation. Another ones were landed on the Fish Market on April 16 and June 26, 2007, respectively. Both of them blistered and their body muscle shrank. This octopus species is regarded to be one year lived. It was seemed that they were under abiotrophy before the death of old age after spawning. The occurrence of freak minor octopus, Octopus minor was thought to be rare phenomenon.