Iridoteuthis merlini is a species of bobtail squid endemic to the open ocean off New Zealand as well as eastern and south-eastern Australia.

[2] I. merlini was discovered along with Iridoteuthis lophia by Dr Amanda Reid in 2021.

She discovered that they had been incorrectly described by Richard Dell in 1959, finding that the S. maoria specimens are actually squids from two different genera: Iridoteuthis and Stauroteuthis.

I. merlini was named in honour of academic Professor Merlin Crossley, deputy vice chancellor of UNSW Sydney.

The squid can adjust the luminous intensity of itself, and can eject jets of the luminescent bacteria into the ocean to deter potential predators.