[7] In 2005, a Japanese research team headed by Tsunemi Kubodera managed to film T. danae in its natural habitat for the first time.

The video footage, shot in deep water off Chichi-jima in the northern Pacific Ocean, shows T. danae emitting blinding flashes of light from photophores on its arms as it attacks its prey.

Juveniles of this species have been observed moving rapidly in the direction of potential predators, as if hunting, to disorient and startle the threat with a mock attack.

In 2008, a mantle of T. danae was discovered by students in Bermuda's Grape Bay, while tentacle remnants were found farther along the shore.

[11] A largely intact 140 kg (310 lb) specimen was found floating around 100km off the South Australian coast and sent to Flinders University in Adelaide where it was dissected in July 2024.