It appears in the seaweed under Sootopolis City.
you will find relicanth underground under sotopolis city (note relicanth is super rare it will take for ever to find
go to soolopitis city then go through the under water hole and then search in the sea weed and you will find it
You can find a relicanth under the sea by sootopolish city or again under the sea on the way to mossdeep city and relicanth's are very hard to find unless u have sweet scent or white flute but it dose take a lot of time to get
go under water in mosdeep city( i think its mosdeep) and keep looking.
You can see and catch Relicanth under the water just outside Sootopilis(spl?) City, in the mossy grass.
you find relicanth by mosdeep city.
You find a Relicanth in emerald by diving in water near Sotopolis City since a Relicanth is a fish. Specifically the creature can be found in either route 124 or 126 in the weeds. Since it is a rare creature it may be difficult to find.
You can find relicanth on route 4
underwater.
you can find it in the routes of 126 to 127 you have to dive in the water though
In Pokemon sapphire u dive under water near that town were u have to dive to get to it and walk thourgh that seaweed or grass eventually u'll find it
You can find Relicanth underwater, but they are rare.