The smallmouth grunt is a medium-sized fish, typically around 6 inches long, with a maximum length of about 8 inches. The smallmouth grunt has an oblong, slightly elongated body with a silvery-gray color and each side is marked by six broad yellow longitudinal stripes. All of its fins—pelvic, dorsal, anal and caudal—are yellow. A common trait of grunts is that the inside of their mouth is red.

The smallmouth grunt’s dorsal fin has 12 spiny rays and 13 soft rays, while the anal fin usually has 3 spiny rays and 9 soft rays, occasionally 10.

Its name, smallmouth grunt, comes from having the smallest mouth of all grunt species.

In its juvenile stage, the smallmouth grunt is distinguished by a dark central longitudinal stripe running the length of its body.

The smallmouth grunt is commonly found along the coasts of the Caribbean sea, the southern Gulf of Mexico and parts of the adjacent Atlantic ocean. It inhabits the tropical waters of the western Atlantic, ranging from southern Florida in the north to the coasts of Brazil in the south, including the coasts of Central America and the islands of the Caribbean, such as the Keys, the Bahamas and Guadeloupe.

Smallmouth grunts typically live in shallow waters from the surface down to about 100 feet. They often form schools around coral reefs, positioning themselves near the bottom, along rocks, sheltered under rock overhangs or the large branches of elkhorn coral.

The smallmouth grunt is a carnivorous fish that hunts at night. Its diet consists mainly of small invertebrates, such as shrimp, mollusks, and marine worms.

In the marine food chain, the smallmouth grunt is preyed upon by larger fish that inhabit coral reefs, like groupers.

Smallmouth grunts reproduce sexually.

The common English name « grunt » comes from the sound the fish makes, which resembles the grunting of a pig. This sound is produced by the fish's well-developed teeth located in its throat.

Grunts are related to snappers but are generally smaller and have more deeply forked tails.

The smallmouth grunt is listed as many other marine species within The IUCN Red List of threatened species. The smallmouth grunt appears in the IUCN Red List since 2015 within the category Least Concern !

Schools of grunts rarely consist of just one species. It’s common to see a mix of species, including the blue striped grunt, the white grunt, the french grunt and the smallmouth grunt, making it tricky to identify the odd one out unless you carefully examine the stripe patterns and colors.