Louvar, Luvarus imperialis
The Louvar, Luvarus imperialis, whose common Spanish name is emperador, is the sole member of the family Luvaridae, the Louvars, known as an emperador in Mexico. This fish is also known as the Luvar. It is a global species found in both the Atlantic and the Pacific. In Mexican waters it is found in the Pacific and is also most likely present in the Atlantic but is not a currently documented resident.
The Louvars have elongated oval compressed bodies that taper to a slender caudal fin base. They are distinctively colored being metallic blue dorsally then transitioning to silver pinkish-red on their sides and silver ventrally. They are covered with indistinct dark spots on the upper two-thirds of their body. They have tinges of red and pink including red anal and caudal fins, a dorsal fin that transitions from red to dark gray, and red to yellowish pectoral fins. Juveniles are covered with dense dark spots. Their head is very deep with a convex profile and a bulging forehead. Their eyes are small and located very low on the body directly behind their small horizontal mouth. Their anal and dorsal fins are long and low both originating mid-body in similar positions. Their anal fin has 18 rays and their dorsal fin has 20 rays; both lack spines. Their caudal fin is large, concave, and circular with one or two small keels at its base. They have long pointed pectoral fins and tiny pelvic fins. They are covered with rough skin and tiny spines. Juveniles go through a dramatic metamorphosis in the shape and size of their head and fins; for example their anal and dorsal fins are higher and have longer bases than the adult versions and their pelvic fins are very long.
The Louvars are an oceanic pelagic species found from the surface to mid-water at depths up to 660 feet. They reach a maximum length of 2 meters (6 feet 7 inches) and 150 kg (330 pounds) in weight. They travel as solitary individuals and consume soft-body plankton including ctenophores, jellyfish, and salps.
Although widespread in tropical and temperate seas cicumglobally, in Mexican waters the Louvars are found only along the west coasts of Baja and the mainland and are absent from the Sea of Cortez and the Gulf of Mexico.
The Louvar cannot be easily confused with any other species due to its coloration and body shape.
From a conservation perspective the Louvars are currently considered to be of Least Concern. As they are more common in the Indo-Pacific ocean, they are sold fresh or frozen on a limited basis in some of the local markets in that area of the world. They are, however, plagued with parasites and therefore not targeted by commercial fishermen for human consumption.
Louvar, Luvarus imperialis. Fish caught off the coastal waters of the greater Los Cabos area, Baja California Sur, April 2003. Length: 91 cm (36 inches). Weight: 16 kg (35 pounds). Photo courtesy of Tommy Garcia, Cabo San Lucas.