Beaubrummel, Stegastes flavilatus
The Beaubrummel, Stegastes flavilatus, whose common Spanish name is jaqueta de dos colores, is a member of a group of small, very colorful reef fishes found throughout the subtropical and tropical regions of the world’s oceans and is a member of the Damselfish Family, known collectively as castañetas and jaquetas in Mexico. This fish is also known as Beaubrummel Major. There are 40 global members of the Stegastes Genus of which seven are found in Mexican waters of the Atlantic and four in Mexican waters of the Pacific.
The Beaubrummel has an oval, compressed body that has a depth that is 46 to 50% of standard length. The adults are light brown to gray-brown in color with blackish scale outlines. The head has violet markings and the rear portions of anal, dorsal, pectoral and pelvic fins are yellowish. Juveniles are bright yellow with a broad blue area on the back and upper part of head with a black ocellated spot at the junction of the spiny and soft dorsal fin junction. The head has a small protrusible mouth that opens in the front with a single row of teeth. The anal fin has two spines and 12 rays; the caudal fin is bluntly forked; the dorsal fin is singular and continuous with 12 spines and 14 or 15 rays, and they have 11 or 12 gill rakers on the lower arch. The body is covered with large rough scales. The lateral line is incomplete and ends under the end of the dorsal fin base.
The Beaubrummel is found in shallow reefs within the surge zone at depths up to 125 feet but normally at depths of less than 50 feet. They reach a maximum length of 16.0 cm (6.3 inches), with this maximum established by a fish that I caught which is pictured below. They are diurnal feeders consuming primarily algae, plankton and benthic invertebrates. They are very aggressive in its feeding habits and when defending its territory. Reproduction is oviparous with pairing of individuals; the eggs are distributed demersal and are sticky and adhere to the substrate.
The Beaubrummel can easily be confused with Cortez Damselfish, Stegastes rectifraenum (uniform brown coloration, 14 to 18 gill rakers on the lower arch). They are also somewhat similar to the Bumphead Damselfish, Microspathodon bairdii (large hump on forehead) and the Whitetail Damselfish, Stegastes leucorus (yellow pectoral fin boarder).
The Beaubrummel are found in all Mexican waters of the Pacific with the exception that they are absent from north of Guerrero Negro on the northwest coast of Baja and in the northern 30% of the Sea of Cortez.
The Beaubrummel is small and of limited interest to most. They are a classic nibbler and difficult to catch by hook and line.