The rostral organ of the coelacanth or similar in many other fish such as Anchovy is a large gel-filled cavity in the snout, with three pairs of canals to the outside.
[1] It is surrounded by an insulating layer of adipose tissue and innervated by the superficial ophthalmic nerve.
Its anatomy and innervation suggest it is an electroreceptive organ[2] used for finding prey in the dark.
This is supported by experiments which showed that coelacanths react to electrical fields produced by a submersible.
[2] This vertebrate anatomy–related article is a stub.