Tigerfish

This article is about the fish called the tigerfish. For the torpedo, see Mark 24 Tigerfish. For the fictional United States Navy submarine USS Tigerfish in the movie Ice Station Zebra, see Ice Station Zebra (film).

Tigerfish is the common name for a variety of species from several different families of fish, usually on account of their colouration or otherwise fearsome appearance and teeth.

Alestiidae

Hydrocynus vittatus

Several species in the genus Hydrocynus of the family Alestiidae are called "tigerfish" and are particularly prized as gamefish. These African fish are found in many rivers and lakes on the continent and are fierce predators with distinctive protruding teeth. The fish bears a striking resemblance, in appearance and habits, to the dorados of South America rivers, but is brilliant silver, as opposed to the gold of the Dorado. They may well have a common ancestor, long ago, when the two continents were united. Indeed, the Dorado is known as the "Tigre del Rio" - Tiger of the River.

The two most common species are probably most recognizable in Southern Africa. The first is the Goliath Tigerfish (Hydrocynus goliath), reputed to reach 50kg in weight, which is found in the Congo River system and Lake Tanganyika, is the largest of the family. The second-largest, scaling up to 15kg, and the southernmost species, is the Tigerfish (Hydrocynus vittatus), commonly found in the Okavango Delta, the Zambezi River and in the two biggest lakes along the Zambezi, Lake Kariba in Zambia, Zimbabwe, and Cabora Bassa in Mozambique, and Jozini dam in South Africa.

Cichlidae

The name "tigerfish" has occasionally been used for species of cichlid in the genus Rhamphochromis. These are large, silver-colored fishes that may have one or two black horizontal lines running the length of the body. These fish are native to Lake Malawi in Africa. They can measure up to 2 meters (6 ft. 7 in.) in length and weigh up to 50 kg (105 lbs.) They also have very sharp teeth that can rip through skin easily; however, they are not known to eat humans. However, according to urbanlegends.com, the goliath tiger "has the somewhat singular distinction of being the only African freshwater fish (excluding the Zambezi shark, which is really a saltwater fish) known to attack humans, and there are several recorded incidents from the Congo River."

Datnioididae

Several species of Coius (or Datnioides, depending on the taxonomic authority) have been referred to as "tigerfish," particularly in fishkeeping books and magazines. They are large, deep-bodied fish with bold vertical black bands against a white, grey, or brownish background. They inhabit fresh and brackish waters in Southeast Asia...

Erythrinidae

The large South American characins of the family Erythrinidae have sometimes been called "tigerfish."

Behaviour

Tigerfish can be considered Africa's equivalent of the South American piranha, though they belong to a completely different family, as they are famous for their ferocity when hunting. They have razor-sharp teeth that are interlocking, along with streamlined, muscular bodies built for speed. Tigerfish are aggressive predators. A tigerfish has a gas-filled sac in its body that it uses as a sound receiver. This transmits vibrations from the water, enabling it to detect any animals nearby and respond accordingly. A school of juveniles can tackle animals of almost any size, including any land animals that stray too close to the water's edge. Adults tend to travel in smaller groups of four or five, but they are no less dangerous. Even an individual can take down prey as large as itself. When food is scarce or the competition for food is too great, tigerfish may resort to cannibalism. This is particularly common in the dry season. Tigerfish have also been known to attack humans, these attacks can be devastating owing to their sharp teeth and aggressive hunting tactics. There are a few recorded death cases.

See also

• Tiger shark

References

• Tiger fish - Guide to the Tiger fish (Hydrocynus forskalii)
• Phillipson, David W. 1985. Mosi-oa-Tunya A Handbook to the Victoria Falls Region Long man Zimbabwe ISBN 0-0546-8657

Tiger

External links

• Fishbase list of species commonly called "tigerfish"
• Fishbase list of species commonly called "tiger fish"