but also to aid in determining the genetic
relationship between S. aequifasciatus
and S. discus. Ready et al. (2006)
employed mitochondrial markers, which
are an effective tool when comparing the
genetic variability in wild populations,
but additional nuclear techniques, such
as the utilization of microsatellites,
have the ability to deliver even greater
variation of alleles and could add valuable
information to the findings. (Farias et al.
 utilized two microsatellite loci
in a Cichlidae phylogenetic analysis but
only S. aequifasciatus from that genus
individuals in a species can vary as
much as color and pattern, which further
confuses taxonomic studies. We will have
to rely on molecular research to decide the
separation of species. In the end we may
still discover that only two discus species
exist, but one of these may be S. tarzoo.
The stream provided plenty of discus habitat via submerged timber, but aquatic plants were limited,
possibly due to the constant flow and being out-competed by the forest canopy.
base of mustard that faded into pearl and a
red rim highlighted the dorsal. Green and
turquoise patterned the face around a dark
pupil, as well as illuminating the pectoral
and anal fins.
No two individuals were alike, each
displaying unique colors and patterns.
Sometimes red specks were only observed
on the anal fin but not on the body.
Interestingly, I found one individual that
did not display any red specks but had a
pale gray color across its entire body, with
minor highlights of topaz on the anal fin
and a light olive forehead. The possibility
of additional discus not bearing red or
orange specks cannot be discounted, as not
all fish in the sample were photographed
due to my concern for their condition out
of the water. I did make a point of paying
attention to the coloration and patterns of
all the captured adults, as smaller juveniles
may not possess their true markings.
Wild discus are obvious high-profile
targets for ornamental collectors and
exporters, due to their striking colors and
high market demand. All the discus that
my guides and I captured were released
after photography. I was informed that
Brazilian authorities had recently forced
the return of a number of discus to the
river after they had been gathered by
a foreign collector. Understandably my
guides were not eager to have their names
tarnished, and they actually encouraged
me to take photographs while the discus
we had taken were released from their
hands. Thoroughly satisfied, I had no
problem with returning these beauties to
the water, thrilled to finally discover some
wild discus and to have touched the water
of the Brazilian Amazon.
A Question of Taxonomy
Previously, Tefé discus had been
recognized as a subspecies of Symphysodon
aequifasciatus PELLEGRIN 1904, known as S.
aequifasciatus aequifasciatus. The recorded
locations of both of these species are known
to slightly overlap (Ready et al., 2006), as
S. aequifasciatus covers a wider range than
the Tefé discus, normally restricted to
the western region of the Amazon Basin.
Although only one individual, it was not
totally surprising that a discus which
did not display any orange or red dots
was discovered. Due to the overlapping
range, the type species S. aequifasciatus
could be well established in the same
region, possibly even interbreeding with
the spotted Tefé variety.
According to some taxonomists there
are only two recognized discus species,
the abovementioned S. aequifasciatus and
S. discus HECKEL 1840—the latter not
commonly found in this western Tefé
region. Ready et al. (2006) has produced
genetic, morphometric, as well as
phenotypic evidence that the Tefé discus
may actually be a separate and third
species, S. tarzoo. Initially described by
Lyons in 1959, S. tarzoo was subsequently
rejected by Shultz in 1960. Interestingly,
Ready et al. (2006) also reports that
S. aequifasciatus and S. discus are more
genetically similar than once thought,
and S. tarzoo is actually further genetically
distanced from both of these species. What
is clear though, is that there are separate
habitat distributions for the three species,
which is suggested to have occurred from
historical tectonic processes.
As with many others, I would be
interested to see the results of further
molecular testing, not only to confirm
the identity of the proposed S. tarzoo,
Farias, I. P., O. Guillermo, and A. Meyer. 2000. “Total
Evidence: Molecules, Morphology, and the Phylogenetics
of Cichlid Fishes.” Journal of Experimental Zoology (Mol.
Dev. Evol.) 288: 76–92.
Froese, R. and D. Pauly (eds). 2007. FishBase. www.fishbase.
org (viewed 01/2007).
Goulding, M., N. J. H. Smith, and D. Mahar. 1995. Floods of
Fortune; Ecology & Economy Along The Amazon. Columbia
University Press. New York, NY. 184 pp.
Ready, J. S., E. J. G. Ferreira, and S. O. Kullander. 2006. “Discus
fishes: mitochondrial DNA evidence for a phylogeographic
barrier in the Amazonian genus Symphysodon (Teleostei:
Cichlidae).” Journal of Fish Biology 69 (Supplement
Starkell, D. 1994. Paddle to the Amazon: The Ultimate
12,000-Mile Canoe Adventure. McClelland & Stewart.
Toronto, Canada. 320 pp. D