Taxonomy
The white grunt was first described in 1801 by Bernhard G.E. Lacepede, a French naturalist. It was originally given the
scientific name of Labrus plumierii, but changed by later workers to the current name of Haemulon plumieri. This name originates
from the greek "haimaleos" meaning blood gums, referring to the red coloration of the mouth interior.
Synonyms include Guabi coarca brasiliensibus Marcgrave 1648, Perca marine capite striato Catesby 1743,
Perca formosa Linnaeus 1766, Labrus plumierii Lacepede 1802, Haemulon formosum Cuvier 1829, Haemulon
arcuatum Valenciennes 1833, Labrus plumieri Cuvier 1834, Haemulon parae Castelnau 1855, Haemulon arara
Poey 1860, Haemulon subarcuatum Poey 1861, Haemylum formosum Scudder 1863, Haemylum arara Scudder 1863,
Haemulum formosum Cope 1871, Diabasis formosus Goode and Bean 1883, and Haemulum plumierii Meek and
Hildebrand 1925.
Common Names
English language common names are white grunt, black grunt, boar grunt, common grunt, flannelmouth grunt, gray grunt, grunt, Key West grunt,
redmouth grunt, ruby red lips, and white snapper. Common names in other languages include aosuji-isaki, bocayate blanco, bococolorado, boquicolorado,
cachicata, coro coro margariteno, gorette blanche, hemulon arara, jolle cocoon, roncadot, ronco blanco,
ronco grande, ronco margariteno, ronco-ronco, and sard grise.
Geographical Distribution
The distribution of the white grunt is limited to the western Atlantic Ocean, from the Chesapeake Bay to the eastern
Gulf of Mexico and Caribbean Sea, south to Brazil. It has also been introduced to Bermuda. It occurs rarely
in waters north of South Carolina (U.S.).
World distribution map for the white grunt
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Habitat
The white grunt is commonly found from the shoreline to the outer reef edge to depths of 80 feet (24 m) and occasionally
offshore over hard bottoms to depths of 115 feet (35 m). The adults form schools with other species of fish
(H. sciurus, H. flavolineatum, Acanthurus chirugus, Mulloidichthys martinicus, and others) during the day over
coral reefs or sandy bottoms. Juvenile white grunts reside inshore in seagrass beds, seeking the shelter among the
spines of the long-spined sea urchin (Diadema antillarum). These juveniles organize into schools according to size.
Grunts produce grunting sounds, hence their common name, by grinding the pharyngeal teeth, amplifying the sound with
the air bladder. The white grunt frequently exhibits territorial kissing displays, consisting of two fish in confrontation,
pushing each other on the lips with mouths open wide.
Biology
White grunt
© George Burgess
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- · Distinctive Features
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The body is moderately elongate, with an elevated and compressed back. The head is long with a sharp snout. Dorsal and anal
fins of the white grunt are completely covered with scales. The caudal fin is forked and the pectoral fin long and falcate. The scales
above the lateral line are larger than those scales located below the lateral line.
- · Coloration
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The white grunt is silvery white to cream-colored, the head is bronze to yellow dorsally while the ventral side of the head
and belly is white. There is a series of dark blue stripes on the head, margined with yellow-bronze running back into the body.
Each scale's margin is bronze and the posterior edge is often gray. Scale rows above the lateral line are larger than those
below the lateral line. The spinous dorsal fin is chalky to yellowish-white, the soft dorsal, soft anal, and caudal fins are
brownish gray. The pelvic fins are chalky, while the pectoral fins range from light yellow to chalky in color. A black blotch
is located on the preopercle and the inside of the mouth is red. The color of this fish is changeable, with the fish appearing in
a shade matching the immediate surroundings. Over sand, near coral, even the darkest spots may fade to a pale yellow color.
White grunts commonly reach lengths of 17 inches (45 cm)
© John Soward
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- ·Size, Age, and Growth
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Commonly reaching lengths of 17 inches (45 cm) and weights of 5.5 pounds (2.5 kg), the white grunt is not a large fish.
The maximum reported length is 18 inches (46.0 cm) and weight is 9.7 pounds (4.38 kg). White grunts reach sexual maturity is attained during
the third year of life when males reach 7.8 inches (20 cm) in length and females 8.6 inches (22 cm) in length. Maximum
age for the white grunt is believed to be between 9 and 12 years. Studies have shown white grunt growth rates are most rapid during the first 30 days of life when
average daily growth is .32mm/day. The average monthly growth rate of adults is 1.4-3.6 mm/day.
- ·Dentition
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Lacking canines, grunts have small, dense, and blunt teeth on the jaws. There are no teeth located on the roof of the mouth.
The pharyngeal teeth are well developed and used for producing the grunting sounds that gives this fish its common name.
- · Food Habits
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The white grunt feeds nocturnally, migrating off the reefs to open sandy, muddy, or grassy areas. Typically moving off the
reef shortly after sunset and returning to the reef just prior to sunrise, large white grunts are the first to leave and last
the return. This fish is considered a generalized carnivore, scavenging benthic crustaceans, mollusks, echinoderms, and small
fishes. Grunts have also been observed to feed on material attached to pilings near offshore platforms. The small juvenile grunts
pick plankton, primarily copepods, from the water column during daylight hours.
Juvenile white grunt
© David Snyder
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- · Reproduction
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Peak spawning occurs during much of the year with peaks occurring during May and June off Florida, August and September
off Puerto Rico and in March and April off Jamaica. The white grunt spawns offshore, over hard bottoms or reefs. There are
no detailed observations on spawning behavior, however it has been observed that pairs of white grunts sometimes face and
push each other with open mouths. It is not known whether this is courtship or territorial behavior. The 0.9 mm diameter eggs
are pelagic and transparent. Hatching 20 hours after fertilization, larvae range from 2.7-2.8 mm in length and contain white
pigment scattered throughout the body. Within 48 hours after hatching, the larvae begin to actively feed. The juveniles
develop a dorsal body stripe at lengths of 23-39 mm. As they mature, pigmentation is less intense and stripes fade and there
is no definite pattern other than the prominent caudal spot. The juveniles occur in shallow water in a variety of habitat types,
including seagrass beds, sand flats, rocky shorelines, and coral reefs.
- · Parasites
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Monogean, digean, acanthocephalan, nematode, and cestode parasites have all been found associated with the white grunt.
Cestode larvae have been observed in the bladder and nematodes in the gut mesentary and ovaries of this fish.
- · Predators
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Snappers, groupers, lizardfishes, spanish mackerel, sharks and other large piscivores feed on the white grunt.
White grunt
© David Snyder
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Importance to Humans
White grunt is considered good quality fish for human consumption and is typically marketed fresh. They are part of a
historic Florida dish, "Grits and Grunts". Although usually served as a panfish, some are large enough to provide small
fillets. This fish has been linked to ciguatera poisoning. Although it is of minor commercial importance, white grunt is
considered a recreational gamefish. It is caught primarily by hook and line off the southeastern U.S., but is also taken
with fish traps, bottom trawls, and seines. In Haiti it is sometimes collected with dynamite. The white grunt
is also collected for public aquarium displays.
Conservation
The white grunt is not listed as endangered or vulnerable with 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.
Prepared by:
Cathleen Bester
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