Japonoconger sivicolus is an eel in the family Congridae (conger/garden eels).[1] It was described by Kiyomatsu Matsubara and Akira Ochiai in 1951, originally under the genus Arisoma.[2] It is a marine, deep water-dwelling eel which is known from Japan, in the northwestern Pacific Ocean. It dwells at a depth range of 300–535 metres. Males can reach a maximum total length of 57 centimetres.[1]