These cowfish have sturdy ‘armor’ plates over much of their bodies, and are generally yellowish to olive green, with dark blue to vibrant blue scrawling patterns and dark spots or splotches. They have ‘horns’ over their prominent eyes, and a sloped profile to a puckered mouth, giving them their cowfish name.
Most of their time is spent in seagrass beds where they eat small invertebrates, vegetation, and anything slow-moving and small enough to become prey.
Order – Tetraodontiformes
Family – Ostraciidae
Genus – Acanthostracion
Species – quadricornis
English language common names are scrawled cowfish, cowfish, shellfish, and trunkfish. Other common names include baiacu-caixão (Portuguese), baiacú-chifrudo (Portuguese), baiacu-de-chifre (Portuguese), bekrapte koeivis (Afrikanns), bel (Marshallese), chapín (Spanish), chifrudo (Portuguese), chupachupa (Papiamento), coffre taureau (French), cofre (Spanish), firhornet kuffertfisk (Danish), kostera czteroroga (Polish), peixe-boi (Portuguese), peixe-cofre (Portuguese), peixe-vaca (Portuguese), taoca (Portuguese), toaca (Portuguese), torito azul (Spanish), torito común (Spanish), torito cornudo (Spanish), and tsuno-hakofugu (Japanese).
Importance to Humans
This fish is considered an excellent food fish and is often marketed fresh. It is especially prized in the Caribbean region for human consumption where it may be locally abundant. However, it has been implicated in boxfish poisoning when not prepared properly. There have also been reports of ciguatera poisoning from eating the flesh of this fish. It is taken primarily in traps and occasionally with seines. This species is also a popular fish for display in public aquarium facilities.
The scrawled cowfish 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.
The scrawled cowfish is found in tropical and temperate waters of the Atlantic Ocean from Massachusetts, Bermuda, and the northern Gulf of Mexico to southeastern Brazil. There has also been a report of this species off the tip of South Africa.
As a shallow water species, the scrawled cowfish resides primarily in seagrass beds to depths of 262 feet (80 m).
The body of the scrawled cowfish is deep, covered with hexagonal-shaped dermal plates that are securely fused together to form a “carapace”. There is a pair of spines projecting from in front of the eyes, similar in appearance to cow horns, hence its common name of “cowfish”. A second pair of spines is located at the rear corners of the carapace.
The carapace terminates around the base of the soft dorsal and anal fins. The terminal mouth is small with fleshy lips. Pelvic fins and spiny dorsal fin are absent. The caudal fin is rounded, truncate, or slightly produced ventrally or dorsally.
The honeycomb cowfish, Acanthostracion polygonius, may be confused with the scrawled cowfish. The easiest way to distinguish the scrawled cowfish is by the color pattern. The majority of the hexagonal dermal plates of the honeycomb cowfish have a pale border surrounding a dark more or less hexagonal ring which in turn surrounds the pale central area of each plate. These dark hexagons are typically open and irregular towards the dorsal margin of the carapace.
The scrawled cowfish two, three or four dark more or less horizontal stripes from the cheek, with the uppermost one located just below the eye and the lowermost at the lower end of the opercular opening. Also, the caudal fin of the honeycomb cowfish is always distinctly rounded while the caudal fin of the scrawled cowfish is either round to truncate.
This species is typically grayish-brown to yellowish-green with numerous blackish-blue to bright blue irregular bars and spots. There are dark spots or blotches on the body. In addition, there are three to four more or less parallel blue stripes on the cheek which can be prominent, however some individuals appear relatively plain, lacking these prominent markings.
The teeth of the scrawled cowfish are moderate and conical in shape with usually less than 15 teeth in each jaw.
Size, Age, and Growth
The maximum reported length of the scrawled cowfish is 22 inches (55.0 cm) total length (TL), however this fish is more commonly 8 inches (20.0 cm) TL. Maturity is reached at approximately 7.5-8.7 inches (19-22 cm) TL.
The diet of the scrawled cowfish includes sessile invertebrates such as tunicates, gorgonians, and anemones in addition to slow-moving crustaceans, sponges, hermit crabs and marine vegetation.
Spawning has been documented off Venezuela during the months of January through February and June through September. Eggs are released in pelagic waters with the larval stage is completed while still pelagic, with juveniles eventually settling out of the water column.
Larger fish are potential predators of the scrawled cowfish, however it may be undesirable as a prey item due to its protective external armor, the carapace.
One documented parasite of the scrawled cowfish is the trematode Parahaliotrema brevis which was located on the fish’s gills.
The scrawled cowfish was described as Acanthostracion quadricornis by Linnaeus in 1758. As a member of the family Ostraciidae, it is a close relative of boxfish and trunkfish. Synonyms appearing in past scientific literature referring to this species include Acanthostracion tricornis Linnaeus 1758, Lactophrys quadricornis Linnaeus 1758, Lactophyrs tricornis Linnaeus 1758, Ostracion quadricornis Linnaeus 1758, and Ostracion tricornis Linnaeus 1758.
Prepared by: Cathleen Bester