NEWS104
29
Gymnorhamphichthys
sp.Peru
allphotos:FrankSchäfer
he reason for the rarityof knifefishes
in the trade isn’t, of course, because
they are rare in the wild. The opposite is
the case, as they represent a significant
percentage of the biomass in Amazonia.
But the demand for such unusual
aquarium occupants is small, as, apart
from a very few exceptions, New-World
knifefishesareunsuitable for thestandard
community aquarium. Being chiefly
crepuscular and nocturnal creatures, the
small knifefish species caneasilygo short
T
The knifefishes of the NewWorld (Gymnotiformes), with at least 173 known
forms, constitute a species-rich order. However, only a very few species are
regularly seen in the aquariumhobby: the BlackGhost Knifefish (
Apteronotus
albifrons
), its brown-colored relative
A. leptorhynchus
, and a number of
Eigenmannia
species (glass knifefishes). Themighty Electric Eel (
Electrophorus
electricus
), which likewise belongs to the New-World knifefishes, is more
frequently imported,forpublicaquaria -andthusendsthe listofspeciesalways
available in thehobby. So it is all themorepleasing that several veryunusual
New-Worldknifefisheshave justbeen importedsimultaneously fromPeru.
Newknifefishes fromPeru
byPaulMenzler
of food,and largeknifefish species regard
small tankmates as snacks. Some
particularly attractively colored species
are also very quarrelsome among
themselves.Hence themajorityof species
ofNew-Worldknifefishesaresuitableonly
for species aquaria and kept only by very
specializedaquarists,and therearen’t that
many of them. But a fewmore would be
very welcome, as New-World knifefishes
are highly interesting creatures about
which far from everything is known - a
rewardingexercise for the keenaquarist!
To better distinguish the New-World
knifefishes from theOld-World knifefishes
(
Notopterus
,
Chitala
, & Co.), with which
they aren’t closely related at all, theNew-
World knifefishes are often also known as
knife eels. All knife eels belong to the
electric fishes that constantly emit
electrical impulses. They use these
impulses for the location of prey, for
spatial orientation, and for intraspecific
communication.Only in theElectricEel are
the impulses so strong that they can be
used to stun prey fishes or enemies. All
other knifeeels are soweaklyelectric that
a human who grasps them won’t feel a
Rarities
Gymnorhamphichthys
portraits:above,
G.
sp.Peruandbelow,
G.cf.hypophthalmus
.
..and the fishes in theirentirety: again,above,
G
.sp.Peruandbelow,
G.cf.hypophthalmus
.
