Another danio species is the blue danio
D. kerri. Although not typically as flush
with cobaltine coloration as their pearl
danio kindred, the blue danios are an
excellent aquarium addition, for they are
long lived, nearly as hardy as the zebra
danios, and in captivity they readily form
very tight schools whose individuals move
together with such speed and precision
as to give the illusion that the school is
a single, uniform entity. It is rare to get
this caliber of schooling formation from
any other danio species. Wearing a base
coat of silvery to coppery scales along the
head and dorsum, these fish have a splash
of electric blue intermingled with golden
speckles and stripes toward the middle
and back portions of the flanks. Like the
black-spotted danio, this species also bears
long, thin barbels extending from its chin.
This species has no special requirements
in the tropical community aquarium.
A final species to be mentioned here
is the Bengal danio. Also known as
the Sind danio, this fish has recently
been the subject of some debate among
taxonomists. Thus, it may be encountered
as either Danio devario or Devario devario.
Either way, this species is one of the
largest of all danios commonly available
in the pet trade. The title of “danio
heavyweight” frequently changes hands
between this fish and the giant danio,
for each can exceed 6 inches in length.
Although typically a bland specimen,
relatively speaking, this fish does sport
an attractive mix of coppery hues and
bluish to silvery flashes along the lateral
surfaces and the caudal peduncle. Unlike
most other danios, this species can
tolerate surprisingly cold environs, for in
nature it hails from the high-altitude and
colder-water streams of northern India
and Bangladesh. An unheated aquarium
that does not drop below 58°F will
support these fish, though I personally
recommend not housing at temperatures
below 62°F. High-end temperatures
should not exceed 77°F.
At the opposite end of the color spectrum
from the blue-clad danios is the glowlight
danio D. choprai, which bears crimson or
orange tinting along its posterior flanks,
caudal fin, and along the dorsum up
through the dorsal fin. Reddish to glowing-orange splashes also occur along the head
and through the upper portion of the
eye. Golden hues and blue ovals are also
common along the flanks; these colors and
patterns are particularly handsome when
overlaid by a spray of reddish to orange.
Hailing from much slower-moving waters
than most of the other danio species, the
glowlight danio has naturally occurring
longer finnage than all other wild danios;
its caudal fin, dorsal fin, and anal fin,
while not as long or elaborate as the long-finned cultivar of the zebra danio, consist
of considerably longer rays and interstitial
webbing than any other species.
Despite its radiant coloration, this species
is not to be confused with the GloFish™
danio, for while the two do bear similar
coloration, the glowlight danio is a naturally
occurring species, and the GloFish™ danio
is a genetically altered cultivar of the zebra
danio. As you might guess, the glowlight
danio is an extremely popular and sought-after species, and as such, it commands
a higher price than most other danios.
Due to increased exportation from Burma,
this species is also becoming more widely
available to U.S. and European hobbyists.
Blue danios Danio kerri.
The glowlight danio Danio choprai.
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