Spanish grunts (scientific name: Haemulon macrostomum) are members of the grunt family (Family Haemulidae) that live on coral reefs in the Western Atlantic Ocean and Caribbean Sea. Grunts get their name from the make grunting sound they make with their pharylgeal teeth.

Spanish grunt. Source: Florent Charpin/www.reefguide.org

Scientific Classification Kingdom: Animalia (Animals) Phylum:--- Chordata Class:------ Osteichthyes (Bony Fishes) Order:-------- Perciformes Family:-------- Haemulidae (Grunts) Genus:---------- Haemulon  Species:----------Haemulon macrostomum (Günther, 1859)

Physical Description

Spanish grunts range from 25 to 43 centimeters in length.  They have a thick body with a forked tail. The silvery body has several black strips running along their upper body and a yellow-green coloration on the dorsal surface. 

Distribution

The species has a subtropical distribution. In the Western Atlantic they are found from southern Florida throughout the Caribbean Sea as far south as Brazil.

Habitat

H. macrostomum is found on coral reefs in water depths of five to 25 meters.  

Feeding Behavior

Spanish grunts are carnivores that feed on crustaceans and sea urchins. They linger in the vicinity of the reef system during the daylight hours. At sunset, they characteristically travel to open water where they feed. They use their strong jaws to get through the tough exoskeletons of their prey.

Behavior

Because they feed at night, Spanish grunts spend their days hiding under ledges or hovering near the protection of the reef. They occasionally form sizable schools.

Reproduction

Spanish grunts are pelagic spawners. Their larvae enter the planktonic stage before settling in nursery area such as shallow back reefs or seagrass beds. 

Threats

Studies at the Saba Reef, one of the richest fish assemblages in the Caribbean Basin, have indicated the chief threats to Haemulon  macrostomum and other reef fishes are overfishing and the residual impacts of the particular chemical dispersant selected by the USA government in the aftermath of the Deepwater Horizon oil spill; this chemical has high persistence and known toxicity to a gamut of marine fauna. Studies by Burke et al. suggest that concentrations of dispersant and other water pollutants are of particular concern in critical lagoon nurseries; these studies suggest that the toxicity of residual dispersant may be much more significant to reef fishes than the actual petroleum release of an underwater oil spill. The dispersant used in the Deepwater Horizon oil spill, Corexit 9500, is known to be much more toxic than the petroleum chemicals it is meant to disperse; moreover, the combined toxicity of Corexit 9500 and petroleum is more toxic to juvenile fish than either chemical set by itself.

Conservation Status

Spanish grunts are not deemed to be a taxon at risk.

References and Further Reading

• J.S.Burke, W.J.Kenworthy and L.L.Wood. 2009. Ontogenetic patterns of concentration indicate lagoon nurseries are essential to common grunts stocks in a Puerto Rican bay. Worldwide Science.org
• Jeffrey T. Williams, Kent E. Carpenter, James L. Van Tassell, Paul Hoetjes, Wes Toller, Peter Etnoyer, Michael Smith. 2010. Biodiversity Assessment of the Fishes of Saba Bank Atoll, Netherlands Antilles. PloS One. 5(5): e10676.
• Encyclopedia of Life. 2011. Haemulon macrostomum Günther, 1859
• Haemulon macrostomum Spanish Grunt
• P.Humann and N Deloach (Editor), 1994. Reef Fish Identification: Florida, Caribbean, Bahamas. New World Publications, Inc. Jacksonville, FL. ISBN: 1878348078
• N.Deloach. 1999. Reef Fish Behavior, Florida, Caribbean, Bahamas. New World Publications, Inc. Jacksonville, FL. ISBN: 1878348280
• Laurier Lincoln Schramm. 2000. Surfactants: fundamentals and applications in the petroleum industry. Cambridge University Press. 621 pages