| Pike topminnow | |
|---|---|
|   | |
|  Scientific classification   | |
| Kingdom: | Animalia | 
| Phylum: | Chordata | 
| Class: | Actinopterygii | 
| Order: | Cyprinodontiformes | 
| Family: | Poeciliidae | 
| Subfamily: | Poeciliinae | 
| Tribe: | Gambusiini | 
| Genus: |  Belonesox  Kner, 1860  | 
| Species: | B. belizanus  | 
| Binomial name | |
| Belonesox belizanus  Kner, 1860  | |
The pike topminnow (Belonesox belizanus), more commonly known as pike killifish and sometimes referred to as topminnow, [2] [3] is a species of poeciliid found from Mexico to Nicaragua. [1] [2] It has also been introduced to Florida, USA. [1] [2] [4] It is the only known member of its genus. [5] The pike topminnow was described in 1860 by Austrian ichthyologist Rudolf Kner, [6] who gave the type locality as Belize, which is reflected in this species' specific name. [7]
Unlike most poeciliids (which tend to be generalists or micropredators), this is a highly specialized predator, with an extremely flexible upper jaw that enables it to take very large prey items for its size. [8]
It grows typically to 9.7 cm (3.8 in) total length, exceptionally to 20 cm (7.9 in). [2] It has an elongated appearance with a flat back profile. The lower jaw is longer than the upper, and upturned. The pike topminnow has large eyes and a dorsal fin set far back on the body. It is a light, olive/brown color with light green iridescence and small black spots on the flanks. The belly is a lighter yellowish white. A dark spot is at the base of the caudal fin. [9] They are also a livebearing fish. [10] [3]
This fish can be found in the aquarium trade, but is not an easy aquarium resident, especially by poeciliid standards.