Fantail n. : A variety of the domestic pigeon, so called from the shape of the tail.

Fantail n. : Any bird of the Australian genus Rhipidura, in which the tail is spread in the form of a fan during flight. They belong to the family of flycatchers.

Example:
My Fantail fish is sitting at the bottom behind plant not breathing good?

Taxonomy
fantails, species, tail, Rhipidura, nest, prey, Willie Wagtail, insect prey, wings, insects, tail feathers, Rhipidura fuliginosa, Rhipiduridae, family Motacillidae, migration, nest building, free encyclopedia, behaviour.

Defination from the web:
Fantail ranges as far as the Snares off New Zealand, in the eastern extend of the family has several endemic forms in western Polynesia. ... Of all the species the Mangrove Fantail has the most restricted habitat requirements, being entirely restricted to ...