The common hatchetfish or river hatchetfish (''Gasteropelecus sternicla'') is a

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

belonging to the

freshwater hatchetfish The freshwater hatchetfish are a family, Gasteropelecidae, of ray-finned fish from South and Central America. The common hatchetfish is the most popular member among fish keeping hobbyists. The family includes three genera: ''Carnegiella'' (fo ...

family (

Gasteropelecidae The freshwater hatchetfish are a family, Gasteropelecidae, of ray-finned fish from South and Central America. The common hatchetfish is the most popular member among fish keeping hobbyists. The family includes three genera: ''Carnegiella'' (fou ...

). Originating in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

in the

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

vian and middle

Amazon Amazon most often refers to: * Amazons, a tribe of female warriors in Greek mythology * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon River, in South America * Amazon (company), an American multinational technology c ...

, the

Guianas The Guianas, sometimes called by the Spanish loan-word ''Guayanas'' (''Las Guayanas''), is a region in north-eastern South America which includes the following three territories: * French Guiana, an overseas department and region of France * ...

and

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

, it grows to about 2.5 inches (6.5 cm). The fish gets its name from its relatively large protruding belly which resembles a

hatchet A hatchet (from the Old French , a diminutive form of ''hache'', 'axe' of Germanic origin) is a single-handed striking tool with a sharp blade on one side used to cut and split wood, and a hammerhead on the other side. Hatchets may also be use ...

. Hatchetfish will often jump out of the water when alarmed, propelled by their large, winglike

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

s. They also jump to catch small aerial insects.

In the aquarium

The river hatchetfish is a schooling species best kept in groups of five or more that spends most of its time in the top-level of the water where it searches for food. These fish are peaceful towards other fishes, but frequently bicker among themselves. Typical lifespan in captivity is around five years, but can live longer. They come from streams in a

climate and prefer water at pH 6–7, a water hardness of up to 15.0 dGH, and an ideal temperature range of (23-27 °C (73-81 °F) . As

carnivore A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

s, they will readily eat many types of small

annelid The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecol ...

worms,

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

s, and

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

, and they will also eat standard flake foods. They have a reputation for being greedy fish. Because of their natural tendency to jump when alarmed, they may jump out of aquarium tanks. To prevent this, the top must either be completely sealed, or the water level lowered so the edges of the tank extend further upwards than the fish are capable of jumping. This is also less common with the addition of floating plants, to provide cover. It is also advised to keep them in a planted aquarium.

References

* * Gasteropelecidae Fish described in 1758 Taxa named by Carl Linnaeus {{Characiformes-stub

In the aquarium

See also

References