Rivulated Mutton Hamlet

Rivulated Mutton Hamlet, Alphestes multiguttatus

The Rivulated Mutton Hamlet, Alphestes multiguttatus, whose common Spanish name is guaseta rayada, is a species in the Grouper or Epinephelidae Family, known collectively as cabrillas and garropas in Mexico. Globally, there are only three species in the genus Alphestes, and all three are found in Mexican waters, one in the Atlantic and two in the Pacific.

The Rivulated Mutton Hamlets are characterized by a rusty brown appearance with darker brown blotches forming irregular bars on their sides. They have deep strongly compressed bodies with depths that are 32 to 37% of standard length), large eyes, and a short snout. Their pectoral fins have five or six regularly aligned transverse bars, a key to identification.

The Rivulated Mutton Hamlets are a non-migratory shallow water species found at depths up to 100 feet. They reach a maximum length of 30 cm (12 inches). They are found hiding in rocky crevices, seagrass weed patches or partially covered with sand during the day and become active predators at night. They rely on camouflage to escape detection. They feed primarily on benthic crustaceans.

In Mexican waters the Rivulated Mutton Hamlet are found from Magdalena Bay southward along the southwest coast of Baja, in the southern two-thirds of the Sea of Cortez along the east coast of the Baja, and along the coast of the mainland south to Guatemala.

The Rivulated Mutton Hamlet is easy to identify, although it is similar and almost identical to the Pacific Mutton Hamlet, Alphestes immaculatus (mottled brown spots along its sides; body width 36-43% of body length).

The Rivulated Mutton Hamlets are too small to be of interest to most. They are normally a “catch and release”, however they immediately attract and are consumed by seabirds since they seldom are able to return to the deep on their own.

Rivulated Mutton Hamlet, Alphestes multiguttatus. Fish caught off Point Palmilla, Baja California Sur, April 2010. Length: 21 cm (8.3 inches).

Rivulated Mutton Hamlet, Alphestes multiguttatus. Fish courtesy of the commercial fishermen of the greater Los Cabos area, Baja California Sur, May 2009. Length: 20 cm (7.9 inches).

Rivulated Mutton Hamlet, Alphestes multiguttatus. Fish caught from coastal waters off Puerto Adolfo Lopez Mateos, Baja California Sur, October 2017. Length: 20 cm (7.9 inches). Upon landing fish was simply gorgeous. Photo taken of the live fish, which was returned to it’s home, but it had already lost significant color.

Rivulated Mutton Hamlet

Rivulated Mutton Hamlet, Alphestes multiguttatus, and Pacific Mutton Hamlet, Alphestes immaculatus, pectoral fin comparisons. Fish of similar length provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, December 2014.