Wavyline Grunt

Wavyline Grunt, Microlepidotus inornatus

The Wavyline Grunt, Microlepidotus inornatus, whose common Spanish name is ronco rayadillo, is a species in the Grunt or Haemulidae Family, known as burros in Mexico. Globally, there are only two species in the genus Microlepidotus, both of which are found in Mexican waters of the Pacific.

The Wavyline Grunts have elongated oval bodies with a depth that is 30 to 32% of standard length. They have an overall silvery-gray appearance with seven to nine narrow orange stripes along their sides; the stripes above their lateral line are broken giving them an overall wavy appearance. Their second anal spine is thicker and longer than their third spine. Their dorsal fin has 14 spines and their pelvic fins are much shorter than their pectoral fins.

The Wavyline Grunts are found over sandy areas adjacent to rocky reefs and caves at depths up to 75 feet. They reach a maximum length of 45 cm (18 inches). They are nocturnal carnivores feeding on benthic crustaceans, mollusks, echinoderms, and small fish. They are a poorly studied species and little is known about their behavioral patterns.

In Mexican waters the Wavyline Grunts are found along the entire west coast of Baja, in the southern three-fourths of the Sea of Cortez, and along the coast of the mainland south to Acapulco.

The Wavyline Grunt can be confused with the Brassy Grunt, Microlepidotus brevipinnis (less prominent stripes; prominent tail spot), the Bronzestriped Grunt, Orthopristis reddingi (less prominent stripes), and the Salema, Haemulon californiensis (large eyes; spine base of dorsal fin longer than rayous base).

The Wavyline Grunts are too rare and too small to be of interest to most.

Wavyline Grunt, Microlepidotus inornatus. Fish caught from the shore at Los Barriles, Baja California Sur, January 2017. Length: 23 cm (11 inches). Catch, photo and identification courtesy of Brad Murakami, Surrey, British Columbia, Canada.

Wavyline Grunt, Microlepidotus inornatus. Fish caught off the beach at Todos Santos, Baja California Sur, May 2005. Length: 35 cm (14 inches).