The rostral organ of the

coelacanth Coelacanths ( ) are an ancient group of lobe-finned fish (Sarcopterygii) in the class Actinistia. As sarcopterygians, they are more closely related to lungfish and tetrapods (the terrestrial vertebrates including living amphibians, reptiles, bi ...

or other fish is a large gel-filled cavity in the snout, with three pairs of canals to the outside. It is surrounded by an insulating layer of

adipose tissue Adipose tissue (also known as body fat or simply fat) is a loose connective tissue composed mostly of adipocytes. It also contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, Blood vessel, vascular endothel ...

and innervated by the superficial

ophthalmic nerve The ophthalmic nerve (CN V1) is a sensory nerve of the head. It is one of three divisions of the trigeminal nerve (CN V), a cranial nerve. It has three major branches which provide sensory innervation to the eye, and the skin of the upper face ...

. Its anatomy and innervation suggest it is an electroreceptive organ used for finding prey in the dark. This is supported by experiments which showed that coelacanths react to electrical fields produced by a submersible.

References

Sensory organs in animals Fish anatomy {{Vertebrate anatomy-stub