Wavyline Grunt, Microlepidotus inornatus

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

Wavyline Grunt, Microlepidotus inornatus. Fish caught from coastal waters off Loreto, Baja California Sur, May 2024.  Length: 32 cm (13 inches).

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

Wavyline Grunt, Microlepidotus inornatus. Fish caught off the beach Agua Verde, Baja California Sur, March 2019. Length: 37 cm (15 inches). Photograph courtesy of Barry Mastro, Escondido, California.

The Wavyline Grunt, Microlepidotus inornatus, is a member of the Grunt or Haemulidae Family, and is known in Mexico as ronco rayadillo. Globally, there are two species in the genus Microlepidotus, both of which are found in Mexican waters of the Pacific Ocean.

The Wavyline Grunt has an elongated oval body with a depth that is 30% to 32% of standard length. They have an overall silvery-gray appearance with 7 to 9 narrow orange stripes along their sides; the stripes above their lateral line are broken giving them an overall wavy appearance. Their anal fin has 3 spines, with the second being similar to the third, and 12 or 13 rays; their dorsal fin has 14 spines and 15 rays; and, their pelvic fins are much shorter than their pectoral fins. They have 17 lower gill rakers. They are covered with scales.

The Wavyline Grunt is found over sandy areas adjacent to rocky reefs and caves at depths up to 23 m (75 feet). They reach a maximum of 45 cm (18 inches) in length. They are nocturnal carnivores feeding on benthic crustaceans,  echinoderms, small fish and mollusks. The Wavyline Grunt 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.

In Mexican waters the Wavyline Grunt is a resident of the Pacific and 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).

From a conservation perspective the Wavyline Grunt is currently considered to be of Least Concern with stable, well documented populations. They are small in stature, seldom seen by humans and of interest to most.