“Archocentrus” sajica, found in the Río Olla Uno and other rivers a little further north; “A.” sajica
is not found in the Río Coloradito, right near the border with Panama, perhaps because of the
Ron Coleman
The Río Olla Uno, about 30 miles from the border, very shallow, and only 5 yards wide, is at the
southern end of the distribution of “Archocentrus” sajica.
push ever further south and west in Costa
Rica to see what was going on with the
cichlids of that region.
frontier feeling, which is not without its
problems (see below).
Unlike the cool, forested rivers and
streams of the northeast, many of these
rivers are slower-moving and exposed (the
forest was cut down in recent decades
to make way for agriculture), making
the water sometimes quite warm (over
80°F), a far cry from the 72°F common in
the northeast. As you get near the coast,
particularly in rivers that have a very direct
connection to the ocean, the reality of large
crocodiles becomes significant. These are
serious crocs—the kind that eat people and
deter even avid cichlid biologists.
After having looked at many rivers using
Cichlids of the South
In a previous article, we described
our encounters with T. sieboldii and
“Archocentrus” sajica. “A.” sajica is the
equivalent of the convict cichlid, yet is
found only in southwest Costa Rica. We
also met “Amphilophus” diquis, a cousin
to the “Amphilophus” alfari we knew up
north. Last year, we pushed to the very
southwest of Costa Rica to a river called
the Río Coloradito, just a few miles from
the Panama border. This region has a truly
Ron Coleman
“Aequidens” coeruleopunctatus
and breeds in this river. This particular
species is an elongate version of one of the
mainstays of New World cichlid hobbyists,
namely “A.” pulcher, the blue acara. It has
similar spangling on the head and the
slightly bent black line along the flank.
Interestingly, other major groups of South
American cichlids such as the pike cichlids
(Crenicichla spp.) or the tiny Apistogramma
species have not journeyed north. The
eartheaters (geophagines) only make
it as far as Panama, as with Geophagus
A crocodile at the Río Tarcoles. The hat gives
you an idea of the size of these creatures—
and why the authors chose not to snorkel in
this river.
lives
our typical sampling scheme—namely to
drive, find a promising river of the right
size (too small and there are no fish, too
large and there are big crocs) under a
highway bridge, jump in and look around,
take data using a GPS and other gadgets,
then drive on—we found one river that
is almost magical: the Río Coloradito. In
this river, we see not only the last vestiges
of the cichlids from the north, including
“Amphilophus” diquis and the most beautiful
T. sieboldii I have ever seen, but we also see
the cichlids from South America poking up
into their northernmost extension.
