Its body is thin and translucent. It has the eyes on the left side of the body and separated by a bony prominence or longitudinal ridge. The mouth has a thorn in the lower jaw and is slightly longer than the upper one. It has scales on the blind side. The color of its blind side is usually cream, while the shade of the ocular (upper) side is adapted to the place it is in. It is hidden by raising a sand curtain with the movement of the pelvic fin and the long dorsal fin, that extends from head to tail fin. Takes advantage when hidden to expertly capture prey that passes overhead. The symmetrical larvae of this species hatch from pelagic roe and within a few weeks, transform in asymmetrical specimens and adopt a benthic existence.
It belongs to the family of the Scofálmidos. It inhabits from shallow waters to depths greater than 400 meters, although it can be found even at 800 meters. It lives in the sandy bottoms of the coastal areas.
It feeds on crustaceans, cephalopods and even other smaller fish.
In some countries the fishing of roosters under 20 cm is prohibited.