Unusual Oto-like fishes

 "Olive K. Charlsey" <achaudh at emory_edu> Date: Thu, 6 Jun 1996
16:57:32 -0400 (EDT)         Wrote: Subject: Brown Otos

	I know that the "Brown Oto" that I recently purchase is NOT
a flexilis. I have had the flexilis before - they are cool. This one
does not have as dark a body and instead of having fairly regular
yellow-white spots like the flexilis, it has a rather random
arrangement of brown spots on a lighter brown body. I have not seen
them before.>>>

I am in a similar situation. About three weeks ago I found in a
local store (northern NJ) some unusual-looking (for me) Otos which I
purchased. They may look a little different from yours though,
although individual variations and  difficulty describing them with
words might explain this.
They were sold under the name of O. flexilis but they do not
resemble the pictures on the Baensch Atlas and on Axelrod's
encyclopedia. In addition, it appeared that within the shipment
there was a single "contaminant" which looked different from the
others. Of course I got him too! For clarity, I will describe them
as "type 1" and "type2" using O. affinis as a reference comparison,
since this is the only Oto species I have seen so far "in person".

Type 1: basic O. affinis body size and shape, but with the following
differences: wider mouth with very pronounced teeth,  heavier and
more rounded head, light gray background upper body color with a
quite variable amount of dark gray speckles. dorsal and ventral fins
with quite thin rays, basically transparent with some dark gray
bands. One individual is slightly smaller than the others. They are
quite active at day, and when they rest on the bottom they quite
characteristically hold their body on the ventral fins, bending up
slightly their tail. They seem to school, at times working their way
up cleaning the aquarium glass walls in groups. They are great algae
eaters, doing an excellent job on the glass, leaves and substrate. I
have put them in a recently set up 10 gal. tank with some plants,
and they have taken care of the initial green algae overgrowth.  
From the pictures seen in the aquarium books, they seem to differ
from O. flexilis  in the reduced thickness of the first ray of the dorsal fin,
heavier head shape and general body coloration pattern. Also, the
eyes are not perfectly round, but rather have a little notch in the
shape of the pupil (similar to Rineloricaria sp.).

Type 2: this is the "contaminant", which does not school with the
three Type 1 individuals I have. Total body length is slightly
longer than O. affinis (~1/4 inch more), and the overall structure
is slightly more robust,  with the tail peduncle tapering in a less
pronounced manner. Eyes, mouth and head size are similar to type
one. The background color is black , with evenly distributed small and very
light brown/yellow dots. Actually, at close examination these color
marks are not really dots, but rather very very short rods (lines).
This fish seems a good cleaner too, although a little more
interested in scavenging the bottom than cleaning glass and leaves.

If anyone can provide help in terms of identification, that would be
welcome. Thanks. 


dionigi.maladorno at roche_com