 |
Longhorn Cowfish
of the Wild West Pacific
Get
along little doggies. As the dust settles from the passage of a cattle
drive and the rough and tumble cowboys riding their horses hollering
and whistling to the herd also pass by, the grassland prairie of the
Wild West America seems like a place of majestic beauty. The Indo-Pacific
also has its very own majestic underwater prairies, horses, and herds
of cattle. In this case, there are lagoons and seagrass beds, seahorses,
and schools of fish. The islanders play the part of the rough and tumble
cowboy here in the Wild West Pacific Ocean.
One very
fascinating fish found in the Indo-Pacific whose very name arouses visions
of Wild West round-ups is the Longhorn cowfish (Lactoria cornuta).
The Longhorn cowfish is a species of Boxfish (family Ostraciidae). Boxfishes
belong to the Tetraodontiformes order which also includes puffers, porcupinefish,
and triggers. Boxfishes are characterized by their "armor-like
carapaces of bony polygonal plates encasing the head and body"
(Meyers, 1999). This armor plating is a vital asset because they are
slow movers and can be easily caught by hand. They move awkwardly using
their side fins and the tail fin only in case of emergency or to get
food. It is common for them to remain motionless in one spot for very
long periods of time.
The Longhorn
cowfish is a solitary creature and may or may not be aggressive towards
other Longhorn cowfish. They prefer to live in sandy and rubble-bottom
habitats found in subtidal reef flats, lagoons, and bays. They can be
observed in nature up to a depth of 100 m. By far, this is the most
well-known cowfish species in the aquarium trade and is one of the largest
cowfish known. They can grow up to 18 inches in the wild, but seldom
reach more than 12 inches in captivity. There is no known sexual dimorphism,
so both male and female display a yellow to olive base color, which
is decorated with white or bluish spots. They are easily recognized
by the horns on the forehead and the bottom rear of the body. The long
horns that this species is named for grow proportionally smaller to
the body as the fish age. Furthermore, its color fades slightly as the
fish ages. If severely stressed, this species can exude deadly toxin
called ostracitoxin. These horns make them hard for predators to swallow.
In any case their flesh is poisonous and would not make for a very good
meal.
The Longhorn cowfish
diet consists of benthic invertebrates. They forage for prey by blowing
jets of water into the sandy substrate. Although the Longhorn cowfish
prefers polychaete worms, they will consume other small invertebrates
in the sand as well. Furthermore, they will also consume plant-type
foods, such as seaweed and spirulina. In captivity, they will associate
the water's surface with feeding and will blow water out of the tank
when they want food. This very fascinating fish species will spit water
from the tank or flap its pectoral fins at the waters surface to get
attention. Because Longhorn cowfish are susceptible to buoyancy problems
when they ingest air from the water's surface, they should not be fed
floating foods.
Currently, the Palau
Aquarium showcases one Longhorn cowfish in the Seagrass Exhibit Area.
Another boxfish here at the Palau Aquarium is the Yellow Boxfish (Ostracion
cubicus). This very friendly and entertaining boxfish is located
at the Reef Crest Exhibit. Be careful, he really likes to spit water
at our guests. He really strives to get your attention. See you at the
next Wild West Pacific Round-up.
Currently, the Palau Aquarium exhibits one Longhorn cowfish
(Lactoria cornuta) in the Seagrass Exhibit Area.
Further reading:
1. Eschmeyer, W.N., Editor, 1998. Catalog of fishes. Special Publication,
California Academy of Sciences, San Francisco. 3 vols. 2905 p.
2. Michael, S.W. 1998. Reef Fishes. Volume 1. A Guide to Their Identification,
Behavior, and Captive Care. Microcosm. Pp. 624.
3. Myers, R.F., 1999. Micronesian reef fishes: a comprehensive guide
to the coral reef fishes of Micronesia, 3rd revised and expanded edition.
Coral Graphics, Barrigada, Guam. 330 p.
Publication No. 03-004
P. O. Box 7086
Koror, Palau 96940
Tel. No.: 680-488-6950; FAX: 680-488-6951
E-mail: picrc@picrc.org; Website; www.picrc.org
|