Gasteropelecidae Common Name:
Marble Hatchetfish Origin and Habitat:
South America: Columbia, Guyana, Suriname, Peru and Brazil. Occurs in small forest streams usually with surface vegetation. Compatibility/Temperament:
Very peaceful; must be kept in groups of at least six and preferably more. Can be combined with other species of the genus, and small peaceful fish such as tetras, rasbora, dwarf cichlids, discus, small catfish and loaches. Marble Hatchetfish Diet
Feeds primarily on insects that are on or land on the water surface. Will accept prepared foods that are small and float such as flakes and freeze-dried bloodworms. Insects such as wingless fruit flies are ideal. Size
Attains 1.5 inches. Minimum Tank Suggestion
18 inches in length Water parameters for Marble Hatchetfish
Soft (hardness to 20 dGH) acidic to slightly basic (pH up to 7.5) water, temperature 24-28C/75-82F. Description
The hatchetfishes are surface fish identified by their rounded keel. The large pectoral fins are attached by powerful muscles that propel the fish from the water, enabling it to glide considerable distances through the air. Studies by Francine Weist (1995) concluded that the pectoral fins are not moved during this "flight" but are used as a powerful thruster to propel the fish from the water as well as to prevent the fish from diving too deeply upon its return to the water [reported in Weitzman & Palmer, TFH, September 1996].
The aquarium must be well covered, and careful attention during maintenance is necessary as the fish will quickly jump if alarmed or frightened. Suitable only for aquaria of small, peaceful fish. Must have floating plants. Newly-imported fish are very sensitive and must be carefully acclimated but once established they are hardy. Very prone to ich during shipment or when under stress. Does not do well in water that is not soft and acidic.
Best suited to an aquarium with minimal surface movement; in larger aquaria when given the option of areas with surface movement from the filter or still water, the fish invariably chooses the latter. It's origin in streams with surface vegetation is an indicator of minimal water movement.
This species has a varied pattern depending upon its origin location; this is illustrated in the accompanying photos which show the significantly-different mid band across the keels. At one time or another, five species were recognized, reorganized into two by Weitzman in 1960, C. strigata
and C. vesca
. Gery (1977) recognized the very close physiological structure and modified these into subspecies as C. strigata strigata
[second photo] and C. strigata fasciata
[first photo] respectively, and these were then combined by Weitzman & Palmer in Reis, et al. (2003) into the presently recognized single species C. strigata
The species in Carnegiella
are the smallest of the hatchetfishes; none posses an adipose fin. The other species in the genus are Carnegiella marthae
, C. schereri,
and C. myersi
, the smallest species.
The family Gasteropelecidae contains three genera: Thoracocharax
with two species, Gasteropelecus
also with two species [G. levis
is possibly a third species (Weitzman, 1996)] and the four recognized species in Carnegiella
; the latter are the most derived or specialized of the hatchetfishes. Weitzman & Palmer hypothesize on the basis of their anatomy that these three genera had a common ancestor in the distant past that was related to some other characiform subgroup. References:
Weitzman, Stanley H. and Lisa Palmer (1996), "Do Freshwater Hatchetfishes Really Fly," Tropical Fish Hobbyist
, September 1996, pp. 195-206.
Weitzman, Stanley H. and Lisa Palmer (2003), "Family Gasteropelecidae" in Checklist of the Freshwater Fishes of Central and South America
, ed. Roberto E. Reis, Sven O. Kullander and Carl J. Ferraris; Porto Alegre: Edipucrs, pp. 101-103.
Wiest, F.C. (1995), "The specialized locomotory apparatus of the freshwater hatchetfish family Gasteropelecidae," Journal of Zoology
, No. 236, pp. 571-592. Contributing Members
The following members have contributed to this profile: Byron