So after posting this article about Endler's livebearers to Usenet, I got an email for from the fish's namesake:



Date: Mon, 17 Jul 95 14:40:57 PDT
From: e..r@lifesci.lscf.ucsb dot ed yew (John Endler)
To: richard@interlog.com
Subject: for Richard Sexton

Dear Mr. Sexton,
A friend gave me a copy of your description of "Poecilia Endler's", and I thought that you might like to know a little more about my namesake!

I discovered these fish in Laguna de Patos, near Cumana, northeastern Venezuela in 1975. They had in fact been collected in 1937 by Franklyn F. Bond, but I didn't know that at the time. (I found his collection in the Museum of Zoology of the University of Michigan). They were found in warm (27-30 degrees C) bright green and hard water in a small lake. The bright metallic green is about the only thing that a prospective mate can see in this very (unicellular) algae-rich water. Interestingly enough, a single population of guppies that I found in southern Trinidad living in a similar habitat was just starting to evolve the metallic green coloration, but it was nothing compared to this species. The original stock was much more polymorphic variable than the present one in the aquarium trade. I have also long since lost the stock but it is supposed to be in the process of being named by some people in Germany. I wanted them to call it Poecilia haskinsi after Caryl Haskins, who knows more about wild guppies than anyone, and who started me out studying these interesting species!

"Endler's Poecilia" got into the Aquarium trade via Klaus Kallman of the New York Aquarium, who got it from the late Donn Eric Rosen, the major taxonomic expert of the Poeciliidae, to whom I gave it so that he could name it. Unfortunately he died before naming it. Klaus gave it to aquarists and added the present common name ("Endler's Livebearer" or "Endler's Poecilia") with out telling me (as a surprise), and I first heard about it during a visit to England in the mid-1980's. It was quite a surprise, but also a disappointment to see how much of the original color pattern variation has been lost through inbreeding and founder events. The wild fish are not always "double swordtails", have much more variable color patterns, and some even have black pectoral fins. But all have the lovely metallic green spots, though variable in size, shape, and position. Although highly variable, the wild fish are not quite as variable as wild guppies, though much more so than P. picta or P. parae--the closest relatives. You mention their not having the "big triangular veil tail", but wild guppies never have the veil tail either; veil tails are an artifact of selective breeding.

"Endler's Poecilia" are not the same as guppies (Poecilia reticulata). One of the first things I did when I found them in 1975 was to try to cross them with wild guppies from a few kilometers away in Venezuela, as well as with other wild stocks of guppies. Occasionally I would get F1 hybrids, but that's all; they are clearly a distinct species. They live only in two sites in Venezuela, one of them (Cumana) next to the city dump, so they might even be extinct now in the wild. Someone should try to go back and check. The second population I only heard about but was unable to find--at the base of the Peninsula de Paria. The fact that they may be endangered makes me happy that they are being kept by aquarists!


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| Prof. John A. Endler                                             |
| Department of Biological Sciences                                |
| University of California                                         |
| Santa Barbara, California, 93106-9610 USA                        |
| tel: 1+ 805-893-8212 (office)    fax: 1+ 805-893-4724            |
| tel: 1+ 805-893-8249 (lab)       e-mail: end...@lifesci.ucsb.edu |
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