Beaubrummel, Stegastes flavilatus

Beaubrummel, Stegastes flavilatus, Juvenile. Underwater photograph taken in coastal waters of the greater Los Cabos area, Baja California Sur, October 2019. Photograph courtesy of Bob Hillis, Ivins, Utah.

Beaubrummel, Stegastes flavilatus, Juvenile. Underwater photograph taken in Zihuantanejo Bay, Guerrero, March 2018. Photograph courtesy of Ron Woheau, Zihuantanejo.

Beaubrummel, Stegastes flavilatus, Juvenile. Fish collected from a tidal pool at Km 17, El Tule, Baja California Sur, January 2007. Length: 4.8 cm (1.9 inches).

Beaubrummel, Stegastes flavilatus. Fish caught from shore at Km 21, Cabo Real, Baja California Sur, April 2015. Length: 12.2 cm (4.8 inches).

Beaubrummel, Stegastes flavilatus. Fish caught out from coastal waters off Point Palmilla, Baja California Sur, March 2015. Length: 12.9 cm (5.1 inches).

Beaubrummel, Stegastes flavilatus. Fish caught from coastal waters off Acapulco, Guerrero, February 2017. Length: 15.5. cm (6.1 inches). Catch, photograph and identification courtesy of Ben Cantrell, Peoria, Illinois.

Blue Chromis, Chromis cyaneaBeaubrummel, Stegastes flavilatus. Fish caught from coastal waters off Acapulco, Guerrero, February 2017. Length: 15.5. cm (6.1 inches). Catch, photograph, and identification courtesy of Josh Leisen (joshadventures.com), Gaylord, Michigan.

Beaubrummel, Stegastes flavilatus. Fish caught from coastal waters off Acapulco, Guerrero, February 2017. Length: 15.5. cm (6.1 inches). Catch, photograph and identification courtesy of Ryan Crutchfield, Tampa, Florida.

Beaubrummel, Stegastes flavilatus. Fish caught from coastal waters off Mazatlán, Sinaloa, October 2021. Length: 16 cm (6.3 inches). Catch, photograph and identification courtesy of Bart, The Netherlands  (worldangler.eu).

Beaubrummel, Stegastes flavilatus. Underwater photograph taken in coastal waters of the greater Los Cabos area, Baja California Sur, May 2018. Photograph courtesy of Bob Hillis, Ivins, Utah.

The Beaubrummel, Stegastes flavilatus, is a member of the Damselfish or Pomacentridae Family, that is also known as Beaubrummel Major and in Mexico as jaqueta de dos colores. Globally, there are fourty species in the genus Stegastes, of which eleven are found in Mexican waters, seven in the Atlantic and four in the Pacific Ocean.

The Beaubrummel has an oval compressed body and has a depth that is 46% to 50% of standard length, thus similar in nature to freshwater bluegills. Adults are light brown to gray-brown in color and have scales with black outlines. Their head has violet markings and the rear portions of their anal, dorsal, pectoral, and pelvic fins are yellowish. Juveniles are bright yellow with a broad blue area on their back and upper part of their head and a black ocellated spot at the junction of their spiny and soft dorsal fins. Their head has a small protrusible mouth that opens in the front with a single row of teeth. Their anal fin has 2 spines and 12 rays; their caudal fin is bluntly forked; and their dorsal fin is singular and continuous with 12 spines and 14 or 15 rays. They have 11 or 12 gill rakers on their lower arch. Their body is covered with large rough scales. Their lateral line is incomplete and ends under the edge of their dorsal fin base.

The Beaubrummel is found in shallow reefs within the surge zone at depths up to 38 m (125 feet) but are normally located at depths of less than 15 m (50 feet). They reach a maximum of 16.0 cm (6.3 inches) in length, with this maximum established by a fish I caught. They are diurnal feeders consuming primarily algae, benthic invertebrates and plankton. They are very aggressive with their feeding habits and when defending their territory. Reproduction is oviparous with pairing of individuals; eggs are distributed demersal and adhere to the substrate due to their stickiness. The Beaubrummel is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Beaubrummel is a resident of all Mexican waters of the Pacific Ocean with the exception that they are absent from Guerrero Negro, Baja California, northward along the central and northwest coast of Baja and from the northern 30% of the Sea of Cortez.

The Beaubrummel can easily be confused with Cortez Damselfish, Stegastes rectifraenum (uniform brown coloration, 14 to 18 gill rakers on lower arch). It is also somewhat similar to the Bumphead Damselfish, Microspathodon bairdii (large hump on forehead) and the Whitetail Damselfish, Stegastes leucorus (yellow pectoral fin border).

The sub-adults are very similar to the Giant Damselfish, Microspathodon dorsalis:

Beaubrummel, Stegastes flavilatus and Giant Damselfish, Microspathodon dorsalis. Both photographs courtesy of Ben Cantrell, Peoria, Illinois, February 2024. Note the differences in the head profiles.

From a conservation perspective the Beaubrummel is currently considered to be of Least Concern with stable, widely distributed populations. They are small in stature and of limited interest to most. They are classic nibblers, thus difficult to catch by hook and line.