More anomalous Japanese octopuses. This condition doesn’t afflict only one arm per individual; one specimen captured in 1884 (first image) had a total of 90 branches, with all arms being affected but one. Another individual captured in 1957 (third image) had 72 branches, with all of its arms being affected; one of the arms (L1) was split so deeply it gave the impression of two separate arms. The cause of this condition is unknown, although since the nerves split far before the arms do externally it is apparently not due to regeneration.
Okada, Y. On Japanese Octopuses with branched Arms, with Special Reference to their Captures from 1884 to 1964. Proceedings of the Japan Academy 41(7) 618–623.
my newest animation for class!