Belonesox belizanus, the pike topminnow, is a species of poeciliid found from Mexico to Costa Rica. It has also been introduced to Florida, USA. The female of the species grows to a length of 20 centimetres (7.9 in) TL, with males growing to a length of 10 centimetres (3.9 in) TL. It is the only known member of its genus. Unlike most poeciliids (which tend to be generalists or micro predators), this is a highly specialized predator, with an extremely flexible upper jaw that enables them to take very large prey items for their size. 
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. There is a dark spot at the base of the caudal fin.
In the aquarium
This fish can be found in the aquarium trade; however, they are not easy aquarium residents, especially by Poeciliid standards. It lives principally near the surface of the water and requires a large tank with plentiful plant growth. Adults feed on large fragments of fish, dragonfly larvae, tadpoles, and worms; it is highly unusual for these fishes to take non-living foods in captivity and failure to keep them sufficiently fed will result in the females cannibalizing the much smaller males. For breeding they require a water temperature of 25–30 degrees Celsius, and the addition of aquarium salt can help. A single spawning can produce up to 100 young. The fry are 2.5–3 cm long and, similarly to their parents, require feedings of live foods (in this case including such things as water fleas, baby brine shrimp, and white worms); the parents are exceedingly cannibalistic to fry, usually requiring the fish keeper to remove the fry for their own safety.
- Froese, Rainer and Pauly, Daniel, eds. (2012). "Belonesox belizanus" in FishBase. August 2012 version.
- Courtenay, W.R., Jr., H.F. Sahlman, W.W. Miley, II, and D.J. Herrema. 1974. Exotic fishes in fresh and brackish waters of Florida. Biological Conservation 6: 292–302.
- Sakurai, A., Y. Sakamoto, and F. Mori. 1993. Aquarium fish of the world: the comprehensive guide to 650 species. Chronicle Books, San Francisco, CA
|This Cyprinodontiformes article is a stub. You can help Wikipedia by expanding it.|