long-armed octopus (Octopus minor)
A small octopus species with long arms, found in East Asian waters. The name is usually written in katakana as テナガダコ.
The long-armed octopus is characterized by its long, slender arms.
Katakana spelling is common for this species name; usually written in kana.
Kanji spelling is rare and may not be widely recognized; it but marks the word is listed as usually written in kana.
From 手長 (てなが, 'long-armed') + 蛸 (たこ, 'octopus'). The exact derivation is straightforward; the kanji spelling is rarely used.