Originally Posted by aro discus
Thanks Byron, I really appreciate the help.
I'm inclined to agree with you about it not being inpaichthys as it does resemble more closely hyphessobrycon. The inconsistency was bothering me but I don't know enough about the scientific differences between them to make an intelligent assesment as to where they belong.
Do you have any recomendations for a comprehensive book on freshwater fish species.....especially tetras?
When I was first getting into fish back in high school (early 90's) I remember a book from the library that described the various types of FW fish but I can't remember what it was called. What I do remember is it had a picture of a beautiful Black Morpho Tetra (poecilocharax weitzmani) before it was described that had been caught with a bunch of cardinals. I guess its that kind of mystery and new discovery is what I have always loved about fishkeeping.
I'm not sure which book that may have been, there were some very good texts during the last century by Innes, Sterba, Axelrod and others. Interesting that you mention Poecilocharax weitzmani, I've had a small group for about 3 years. A beautiful fish but one you rarely see in the aquarium; it spent all day among plants and wood. Difficult to feed too; I weaned mine onto frozen bloodworms but that was all they would ever eat. They have "disappeared" one by one.
Books on fish are difficult these days, as the classifications are changing so frequently. The knowledge of DNA and cladistics was not available back when many of our fish were initially described, and it is difficult enough to keep up via the internet. But a good reference work on aquarium fish which contains reliable care and maintenance data is the Baensch/Riehl series Aquarium Atlas
. There are now six volumes in German, and the first 4 have been published in English; I have 1, 2 and 3. Of course any fish discovered within the last 10 years is not likely to be in these, the originals were published in the 1980's-1990's and aside from amendments to the format (indices, etc ) I don't think they have been significantly revised. Volume 1 contains most of our commonly-seen fish.
Specifically on characins, the only comprehensive work is Jacques Gery's 1977 Characoids of the World
. I have this and refer to it regularly, though the methods of classification were very different back in those days. Gery lived up until 2005/6 but never revised the work, probably because he knew it was next to impossible. Many of his hypotheses have subsequently been found true, some not, with the advent of DNA and cladistic analysis. Weitzman has written that a major reclassification of the characidae is needed, but to do this accurately there will have to be significant collections made throughout South America in order to ascertain the species. It is becoming obvious that many of the widespread species have evolved fairly recently (in geological terms) into new species due to their habitat and collectors are now accessing streams that have previously been unexplored.
As one very recent illustration, the commonly-called Black-winged Hatchetfish, scientifically described as Carnegiella marthae by the ichthyologist George Meyers in 1927; the type locality was Venezuela. In 1950, Fernandez-Yepez described a near-identical species, C. schereri, from Peru. [It is probable that some of the Black-winged hatchetfish in the hobby are actually this latter species and not true C. marthae.] But this has suddenly (this year) become even more complicated. The "Black-winged hatchetfish," has for some time been known to be widespread in the Rio Negro floodplain (Brazil). Very recent research (Piggott, et al., 2011) has identified highly differentiated and divergent population groups representing three cryptic species. The authors of this paper suggest that additional collection throughout the basin will be needed to confirm the exact number of species. When you realize that this basin is larger in area than the entire country of France, and much of it is thick jungle that has still be unexplored, you can appreciate the enormity of the task. There are minor external differences in the 3 proposed species but otherwise the fish are identical and clearly evolved from a common ancestor. You can read a bit more in our profile of Carnegiella marthae.
The Serpae Tetra, Hyphessobrycon eques, is widespread over most of the Amazon basin, and there are minor differences in the shoulder patch depending upon the location. Dr. Stanley Weitzman (1997) has suggested that the "species" may be a complex of closely related species that are geographically quite variable and occur over a wide area of Amazonia; it is quite possible that this "species" may actually be several different species, each endemic to specific river basins; this will only be ascertained after collections from many locations have been studied in detail.
Just two examples of many that illustrate why it is so difficult to write a book on the characins.