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In 1993 this article won "Article of the Year" from FAAS (Federation of American Aquarium Societies).
The Three Species of Rummy-Nose Tetras



- Randy Carey -

previously printed in the March/April '93 issue of the AquaNews,
a publication of the Minnesota Aquarium Society.

all rights reserved by the author and M.A.S.
The Baensch Atlas spells the name as "Rummy-Nose." I have chosen to repeat this spelling as opposed to "Rummy Nose" or "Rummynose." Not all Rummy-Nose Tetras are created equally. Although the common name used by pet shops may say "Rummy-Nose," be aware that three distinct species are sold as such. One week I found three distinct types at the same retailer and under the same common name. While the store was unaware and unconcerned of what it had, I gratefully added to my characin collection.
History
In 1924 an aquatic pioneer named Ahl described the original "Rummy-Nose" with the scientific name Hemigrammus rhodostomus. The specific name means "rose mouth" (from the Greek words rhodon + stoma). At first this species was seldom imported because of its frailty, breeding difficulty, and lose of red in captivity. It became more popular after World War II when aquarists realized it required pristine water with a low pH.
1
Jacques Géry has been renown as a characin expert. He authored the 1977 TFH book Characoids of the World.
2
Reportedly, georgiae was named after Géry's wife, Georgie.
The second species was exported in 1956. It failed to attain a sizable place in the hobby since its red, though more permanent than that of H. rhodostomus, is neither more intense nor more extended. In 1964 French aquarists Géry ¹ and Boutiere described this indisputably distinct species as Petitella georgiae². It acquired the common name "False Rummy-Nose."
As the fish export centers expanded and evolved, a newer "version" of H. rhodostomus became available. It was collected from farther inland than the previous Rummy-Nose. Not only is its red more intense and more permanent, but this rose color extends well past the gill. These exports bearing these new and improved features supplanted the demand for the previous two Rummy-Noses. Because of its superior color, this species is still the primary Rummy-Nose of pet stores.
3
Originally written as an academic paper, Géry's book Characoids of the World (1977) provides the most photos and identification criteria for the characins known at that time.
In Characoids of the World ³ (1977), Géry illustrated the visual distinctions of the tail markings between the first two species. Elsewhere in this book he suggests that the new version of H. rhodostomus is actually a distinct species. For some time Géry was unable to formally describe this new form as a distinct species from H. rhodostomus. Lacking were the exact collecting locations as well as original H. rhodostomus specimens and materials. After Heiko Bleher conducted a thorough collecting expedition, Géry was able to establish that this new form was indeed a new species. As recently as 1986 and in the hobby publication TFH, Géry and Mahnert described Hemigrammus bleheri. The specific name was given in honor of Bleher to whom their research was indebted.
As an editorial comment to Géry's and Mahnert's description, TFH suggested the following common names for each of the three species: P georgiae as the Black-fined Rummy-Nose, H. rhodostomus as the Banded Rummy-Nose, and H. Bleheri as the Brilliant Rummy-Nose. Although these common names have been used, they have not attained wide circulation. Baensch still uses the older names: Rummy-Nose for H. rhodostomus and False Rummy-Nose for P. georgiae.
Confusion in Published Literature
Within much of the printed material used by hobbyists today, labels and references are erroneously attached to the wrong Rummy-Nose species. Part of the blame must reside with the exporting of H. bleheri as the commercial Rummy-Nose for twenty-some years before it was described. Aquarist and publishers assumed that their Rummy-Noses were H. rhodostomus. Even since the new description in 1986, many articles have failed to make the proper distinction. A word of warning: do not trust a Rummy-Nose photo with its caption.
A recent source that accurately portrays each of three Rummy-Noses is Baench's Aquarium Atlas (pgs. 273, 279, and 309). Compare its photos with the visual differences set forth later in this article.
Classification

4
This is not the first time Géry has placed similarly looking species in different genera. He split the three "neon tetras" into two subfamilies. However, later rigorous testing provided evidence that the three species were indeed immediate descendants from the same species.
5
Other Hemigrammus species commonly available to hobbyist include Glowlight , Head-and-Tail Light, Buenos Aires, Pretty Tetra, and Gold Tetra.
6
These are two features which Géry observed and noted in his description of bleheri.
[Carey 98:] Since I wrote this aricle, the classification of tetras has undergone re-evaluation. I have been enlightened to some of the current issues involving the two subfamilies of the "Rummy-Noses," so this section "Classification" is my current rework of the topic.

In describing the third Rummy-Nose species, Géry assigned it as a Hemigrammus along with the original Rummy-Nose. According to Géry Petitella georgiae belongs not only to a different genus, but to a different subfamily. Of course this suggests that P. georgia has followed a noticably different evolutionary path and coincidently "happens" to look similar to the other two Rummy-Nose tetras. Such a conclusion should be questioned. [4]
I am not aware of any further study on the relationship of the three Rummy-Nose tetras with each other. The visual similarities are so striking that, for the time being, I believe they probably share a common ancestor unique to these three.
Indeed, the two Hemigrammus species are deemed "peripheral" to the genus.[5] For instance, compared to Hemigrammus, the horizontal length of their anal fins is quite short and the number of anal hooks are low.[6] So, perhaps the three don't belong to Hemigrammus, but wherever they ought to be classified, I suspect that the three belong together.
I later will discuss the visual distinctions. However, based on visual features, H. rhodostomus seems to be the middle species. In other words, in features where H.bleheri and P. georgiae differ, rhodostomus either shares those features with one or the other, or it shows a compromised marking between the two differences.
Given that Géry acknowledged that the two Hemigrammus are "unquestionably close," I would speculate that P. georgiae is a more primative species and that H. bleheri recently speciated from H. rhodostomus.
Distribution
The following illustration displays the distribution of these three tetras. Apparently the natural habitat of each Rummy-Nose species does not overlap with the others.

P. georgiae
H. rhodostomus
H. bleheri

7
The Amazon's tributaries are distinguished by their water color: black, white, and clear. "Black water" is colored of decaying vegetation and leeched tree bark.

While both Hemigrammus species are native to "black water" tributaries, P. georgiae is found in "clear water."[7] H. rhodostomus is found well downstream of the Amazon and Orinico river system. Conversely, the localities of H. bleheri and P. georgiae are confined to tributaries which are noticeably upstream off the Amazon. Note that H. bleheri (the fish described in 1986 and most commonly available in pet stores) is found at only one location--at the middle of Rio Negro.
8
This description was published in 1986. I am unaware of any further discussion on the status of a possible fourth Rummy-Nose. Although no photos of this fish were provided, I have seen photos of H. bleheri that betray its classic description: the red is restricted and the black caudal bands are much thinner. I would assume it is H. rhodostomus, except its posterior line is quite subdued. Could this be the population referenced as a possible fourth species? For an example, see Axelrod's sixth edition Atlas, page 295, left column, 2nd photo from top.
A Fourth Rummy-Nose Tetra?
In their article[8] describing H. bleheri, Géry and Mahnert briefly discussed a few additional specimens. These came far upstream of the tributary system from which H. bleheri originates. These specimens were very close to H. bleheri. However, they considerably lacked the color of those specimens from the middle Rio Negro.
Furthermore, the authors say, a particular skull bone distinguished it from the two Hemigrammus species. Because not enough specimens and data were available, the authors refrained from any conclusion. They acknowledged that these specimens might be only a western population of the same species. This locality apparently is not a common source for pet store Rummy-Noses.
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