Crested Bigscale

Crested Bigscale, Poromitra crassiceps

The Crested Bigscale, Poromitra crassiceps, whose Spanish common name is aletudo crestada, is a species in the Bigscale and Ridgehead or Melamphaidae Family, known collectively as aletudosin in Mexico. Globally, there are thirty-seven species in the family placed in five genera. There are twenty-two global member members of the genus Poromitra genus, three of which are found in Mexican waters, all in the Pacific.

The Crested Bigscales have elongated rectangular bodies with a serrated crest on top of their head. They are black with dark fins. They have three dorsal spines with 11 to 14 soft rays and one anal spine with 8 to 11 soft rays. Their caudal fin is shallow and forked and their pectoral fins are long, slender, and longer than the head.

The Crested Bigscales are a mesopelagic and bathypelagic species found at depths between 450 and 13,120 feet. Juveniles are found in shallower water than adults. They reach a maximum length of 19.0 cm (7.5 inches). They migrate vertically toward the surface for feeding during the night. Adults feed on small crustaceans. They are oviparous producing planktonic eggs and larvae and have a lifespan of nine years.  The Crested Bigscales are poorly studied and very little is known about their behavioral patterns.

In Mexican waters the Crested Bigscales are found in all waters of the Pacific.

The Crested Bigscales is a straightforward identification and they cannot be easily confused with any other species.

The Crested Bigscales are too rare and too small to be of interest to most.

Crested Bigscale, Poromitra crassiceps. Fish collected in a deep water trawl net off Point Loma, California, August 2010. Length: 8.1 cm (3.2 inches).  Catch and identification courtesy of H.J. Walker, Jr., Scripps Institute of Oceanography, La Jolla, CA,