Hatchetfishes

The blackwing hatchetfish, Carnegiella marthae, is a small freshwater hatchetfish from the upper Orinoco in Venezuela and the rio Negro in Brazil. It appears to be a stenotypic inhabitant of blackwater, found in igapó and igarapé habitats with overhanging vegetation and leaf litter. Very peaceful but small and timid, it is best kept in a group of 10 or more with similarly sized, peaceful fishes.

The pygmy hatchetfish, Carnegiella myersi, is a tiny freshwater hatchetfish from the Peruvian Amazon basin, with a second population in Bolivia. The smallest and most delicate of the nominal hatchetfishes, it has a shallower, rounded keel that gives it an elongate profile. It lives in small, shaded, shallow forest streams and must be kept in a group of at least six, away from active tankmates.

The marbled hatchetfish, Carnegiella strigata, is a hatchetfish from the Amazon and Orinoco basins and coastal rivers of Guyana and Suriname. Popular in the hobby, it is collected for the trade mostly in the rio Negro basin in Brazil. Its larger size and dark, marbled pattern set it apart from congeners, though the pattern varies and the wide range may be open to question. It appears to live only in blackwater.

The silver hatchetfish (Gasteropelecus levis) is a freshwater hatchetfish found only in the lower Amazon basin in the state of Pará, Brazil. It spends almost all of its time at or just below the surface, and can leap from the water and glide for several metres to catch flying insects or escape predators. It lives in open water of larger igarapés, streams and floodplain lakes.

The common hatchetfish (Gasteropelecus sternicla) is a freshwater hatchetfish from South America, described from Suriname. Its distribution is questionable, with records from the middle Amazon, Venezuela, Guyana, French Guiana and the Río Paraguay basin. It spends almost all of its time at or just below the surface. The most frequently seen of the silver hatchetfishes, it is peaceful but nervous and shy.

The spotfin hatchetfish, Thoracocharax stellatus, is the most widespread neotropical hatchetfish, recorded from much of South America. It is told from its only congener, T. securis, by a prominent dark spot in the dorsal fin, and is sometimes traded as 'platinum hatchetfish'. It feeds almost entirely on insects, and a tightly fitting cover is needed because it can clear several metres in one jump.