Bluestriped Grunt

Bluestriped grunt. Photo © Doug Perrine
Bluestriped grunt. Photo © Doug Perrine

Haemulon sciurus

These almond-shaped fish are yellow with blue horizontal stripes, and grow to almost 18 inches long, but generally are found at 14 inches. They prefer mangroves, reefs or sea grass beds where they school with other bluestriped grunts and even mix with other grunts. Their name comes from the grunting noise they make by grinding their teeth together.

Order: Perciformes
Family: Haemulidae
Genus: Haemulon
Species: sciurus

Common Names

Bluestriped grunts live in reef habitats. Photo © Mark Younger
Bluestriped grunts live in reef habitats. Photo © Mark Younger

English language common names for this species include bluestriped grunt, blue striped grunt, boar grunt, golden grunt, humpback grunt, redmouth grunt, and yellow grunt. Other common names include abiquara (Portuguese), biquara (Portuguese), biquara-do-raso (Portuguese), boca-de-fogo (Portuguese), bocayate amarillo (Spanish), brons (Papiamento), cambuba (Portuguese), capiuna (Portuguese), gorette catire (French), grons (Papiamento), hemulon smuzkowy (Polish), koorkoor (Papiamento), korkor (Papiamento), neertje (Dutch), robeki oromani (Papiamento), ronco amarillo (Spanish), ronco catire (Spanish), ronka (Russian), sarde jaune (French), uribaco (Portuguese), xira (Portuguese), and xira amarela (Portuguese).

The common fish name “grunt” is derived from the grunt-like sound produced when it grinds the teeth deep within its throat. The sound is amplified by the taut air bladder that acts as a resonator. Grunts are closely related to snappers, but are generally smaller and have deeply notched tails.

Importance to Humans

The bluestriped grunt is of minor commercial fisheries importance. However when it is caught, it is marketed fresh. There have been reports of ciguatera poisoning from human consumption of this fish.

This grunt tends to be more wary than most grunts, often swimming away upon approach by divers. However, it is valued as a specimen for public aquarium facilities.

Conservation Status

The bluestriped grunt is not listed as endangered or vulnerable by the World Conservation Union (IUCN). The IUCN is a global union of states, governmental agencies, and non-governmental organizations in a partnership that assesses the conservation status of species.

> Check the status of the bluestriped grunt at the IUCN website.

Geographical Distribution

World distribution map for the bluestriped grunt
World distribution map for the bluestriped grunt

The bluestriped grunt is found in the western Atlantic Ocean from South Carolina (U.S.) south to Brazil, including the Gulf of Mexio, Caribbean Sea, and Bermuda.

Habitat

This grunt is common in mangroves, reefs, and seagrass beds at depths to 98.5 feet (30m). Adults form small groups over coral and rocky substrates, especially near drop offs. The juveniles are abundant in shallow turtle grass (Thalassia testudinum) beds. Bluestriped grunts are known to occasionally face and push one another with open mouths. Although the purpose for this behavior is unknown, it is believe to be related to either courtship or territory defense.

Biology

Bluestriped grunt. Photo © George Burgess
Bluestriped grunt. Photo © George Burgess

Distinctive Features
The dorsal profile is moderately arched on this deep-bodied grunt. The upper jaw of the bluestriped grunt reaches to below the center of the eye. Bluestriped grunts have scales that are enlarged above the lateral line, while scales below the lateral line are oblique.

Coloration
The head and body of the bluestriped grunt are yellow with narrow horizontal blue stripes. There is also a stripe with a distinctive arch under each eye. The spiny dorsal fin is yellow while the soft dorsal and caudal fins are dark and the anal fin is dusky yellow in color. The pelvic and pectoral fins are chalky in color. The inside lining of the mouth of the bluestriped grunt is a bright red.

Small juvenile bluestriped grunts, less than 22 mm in length, have prominent melanophores on the caudal penduncle. As the fish grows, the melanophores on the head and body blend into a dark stripe that runs from behind the eye to the caudal spot. At 50mm in length, the caudal spot spreads onto the caudal fin and the fish takes on the adult coloration.

This grunt closely resembles the french grunt (H. flavolineatum), however the bluestriped grunt is much larger and its blue stripes are more broad and run horizontal rather than diagonal.

Bluestriped grunts forage for invertebrates and small fishes. Photo © George Ryschkewitsch
Bluestriped grunts forage for invertebrates and small fishes. Photo © George Ryschkewitsch

Dentition
This fish is named for the pig-like grunts produced with their well-developed pharyngeal teeth located in the throat. Resembling snappers, grunts have weaker teeth in the jaw and lack canines.

Size, Age, and Growth
The maximum length of the bluestriped grunt is 18 inches (46 cm) with maturity attained at lengths of 12-14 inches (30.5-35.5 cm). The maximum recorded weight of this grunt is 1.7 pounds (750 grams). Juvenile bluestriped grunts grow rapidly, gaining approximately 0.50 mm in length per day.

Food Habits
Bluestriped grunts forage primarily in seagrass and mangrove habitats, feeding on crustaceans, bivalves, and various small fishes.

Reproduction
Spawning occurs during the months of January to April in the Caribbean Sea. Knowledge about the spawning behavior of the bluestriped grunt is limited. Juveniles settle into seagrass beds at sizes ranging from 9-17mm in length.

Bluestriped grunt. Photo © John Soward
Bluestriped grunt. Photo © John Soward

Predators
Larger piscivorous fish such as sharks and groupers are potential predators of the bluestriped grunt.Parasites
The monogean, Encotyllabe spari, has been documented as an endoparasite in the bluestriped grunt.

Taxonomy

George Shaw, an English naturalist, described the bluestriped grunt as Haemulon sciurus in 1803. Synonyms include Haemulon formosus Castelnau 1855, Haemulon similis Castelnau 1855, Haemulon luteum Poey 1860,Haemulon multilineatum Poey 1860, Haemylum elegans Scudder 1863, Haemulum elegans Cope 1871, and Haemulum luteum Cope 1871.

Prepared by: Cathleen Bester