In the Gulf of Thailand off eastern Thailand Idiosepius thailandicus was recorded among seaweed in the littoral zone in Rayong Province  and in a mangrove habitats in Chanthaburi Province. In mangrove habitats the squid adhered their eggs to the roots of the mangrove.
In the Gulf of Thailand off eastern Thailand, Idiosepius thailandicus was found among seaweed in the littoral zone in Rayong Province and in mangrove habitats in Chanthaburi Province. In mangrove habitats, the squid attached their eggs to the roots of the mangrove.