a collection record for Rivulus "rubrolineatus"

["Bruce J. Turner" <fishgen at vt_edu>]

I sent this out yesterday but never saw it on the listserv so I am
re-sending it.  Please forward it to any potentially interested parties,
especially Rivulus specialists.  Note:  I apparently lack Jean Huber's most
current e-mail address (my mail, including this note, keeps bouncing), so
if someone could forward it to him I would be obliged.



1 male and 1 female of this species were taken on 10/24/02 in a small
stream at the town of San Regis (Loreto Province, Peru) on the W. bank of
the Rio Maronon by Sr. Alfredo Chavez acting on my behalf while I was ill
and confined to my cabin on the tourboat (S.S. Delfin).  The specimens were
eventually turned over to an exporter in Iquitos and were not retained.
The male specimen most strongly resembled the uppermost photograph in the
right hand column of page 156 of Killifishes of the New World by Lothar
Seegers. The female resembled that of the lowermost photo in the same
column, but had considerably more darker markings along the lower flanks.
The male also strongly resembled the fish identified as R. taeniatus on p
159 of the same work.

The fish from San Regis appeared to be very similar to examples of this
species discussed previously by Ken Normandin and Dave Schlesser.  They
also appeared to be very similar/identical to Rivulus that were shipped in
some numbers from Leticia, Colombia in the early 1960's, along with A.
peruensis, under the name "Rivulus Africanos" (the "Africano" is one of the
local names for A. peruensis). At that time, the form was generally
identified as R. urophthalmus by aquarists in the New York area (including
myself).  It was not particularly highly valued, though large males, well
acclimated, can be quite pretty or even striking (they resemble A.
striatum). It was easily bred, and males were not too hard on females, but
few bothered to seriously propagate it at that time.  I believe that
Axelrod has published a photograph of a mature pair of this form under the
name R. urophthalmus, but I cannot lay my hands on it at the moment.  The
mottled markings on the flanks of the female are quite characteristic.

If there is any real interest in the San Regis population on the part of
Rivulus specialists, I suspect that a collection and importation could be
arranged, though at some cost.

Some editorial remarks:

I use the name "rubrolineatus" in this note solely in the interest of
efficient communication---it appears to be accepted by aquarists.  Though
there is lots of variation in color pattern,  I am aware of no data which
serve to convincingly separate this form from the highly variable R.
urophthalmus found throughout the middle and lower Amazon basins (I am
familiar with material from Belems and have seen specimens exported from
Manaus as well).  Moreover, if the photograph of R. taeniatus (see above)
is correctly identified, then the similarities between "taeniatus" and
"rubrolineatus" are so great that I would be strongly tempted to use the
former name (Fowler, 1945) rather than the latter.  I suspect that it will
be many years before these issues are resolved.

Several Rivulus species, as they have been generally defined, range over
vast distances and are geographically variable (e.g. R. harti, which
apparently grades gradually into "bondi" and R. geayi which grades
gradually into R. "strigatus"). Depending on the nature of the variation,
some of these may well be eventually divisible into separate, regionally
coherent species.  However, absent data which support such divisions (other
than color patterns) I am more comfortable using the smallest number of
names possible. I recognize that this opinion is not shared by all my
colleagues, and that some will have exactly the opposite view.


******************************************************************************

					Bruce J. Turner
					Assoc. Professor of Biology
					VPISU, Blacksburg, VA 24061
					(540)-231-7444
					fishgen at vt_edu


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