Danio year 2009: Danio quagga

In March last year, our PhD student Te Yu Liao and I were able to collect along the Myanmar border with India, in tributaries to the Chindwin River. Our intended stops were Kalaymyo and Tamu, but we also tried stopping at streams along the road. It was very dry at the time, and even large rivers reduced to small streams.

Stopping by one of these streams, in the heart of a large village, we seined a pool with some vegetation. And in there was a zebrafish! Zebrafish in Myanmar, in the Ayeyarwaddy drainage. No way. It had to be something new, and as we have learned from Meinken, all danios are striped anyway. The fish went into formalin, and the chase for the next specimen commenced.

The stream

After one more hour, still not one more specimen of this schooling species, but hundreds of Danio albolineatus, and we were called to inspection by the local authorities, so we had to move on. Indeed, we were in a hurry between Kalaymyo and Tamu to arrive at our destination before dark, not only because of likely shortage of accommodation in Tamu, but also because we were given only one day of permanence in Tamu and would need to spend time with local authorities to explain our presence. But hand on heart, you can't leave a new species like that? Well, we moved on convinced we would find more specimens in some other place. Unfortunately it did not turn out so. We left Tamu with four more specimens from the market, where they hid in heaps of plenty of other little fish, dead to the bone, and with the total of five we eventually left Myanmar. Myanmar markets have large fish, but also large quantities of very small ones, used to prepare a special fish paste, ngapi. In the early morning there is thus plenty of fresh fish in the market and saves on collecting in the wild, with the caveat that fresh fish from the stream preserve better.

So, we were back with only formalin preserved specimens, and in the present times that is bad, because DNA sequencing is in the vogue, and generally a useful tool to check on phylogenetic relationships, and because formalin denatures DNA. Some of us can still do systematics without DNA, however, and that we did. The striped danio turned out not very similar to zebrafish at all, except in the general colour pattern. It is rather related to the spotted species, Danio kyathit from the neighbouring upper Ayeyarwaddy drainage and with one specimen recorded from the uppermost Chindwin.

The mammal: Equus quagga.

We named our striped danio Danio quagga. Quagga is the species or subspecies epithet of one of the zebras, so that within the genus of the zebrafish there should be at least one species with a name associating to zebras. We didn't call it Danio zebra just not to confuse things for the zebrafish people (and perhaps, in the end, ourselves). (But wouldn't it have been fun?)

The fish: Danio quagga, holotype.

See above what it looks like, now that the holotype has been dead for a while. Exciting as it was to encounter another zebrafish in the wild, I am not convinced that this will become an ornamental fish hit. Our comparisons suggest that it is most close to Danio kyathit, which hasn't outcompeted the leopard danio in the hobby. It is also somewhat larger than a normal Danio rerio, requiring more swimming space (the holotype was the only one in 50 m of stream ...). And, of course, why would we need another striped danio in our tanks. Seems we have exhausted danios as ornamental fish? But there is of course more to a fish than populating an aquarium. We are gradually building a phylogenetic history of danios, and then it is just great to find a sister-species pair, a split branch on the tree, rather than having single branches of uniques. Now we will move on to connect D. quagga and D. kyathit to the rest of the tree.

If you want to read the original description, you can download an Open Access copy, which you can share with families and friends as much as you like. Just click on the reference below. It's magic!

Reference
Kullander, S.O., T.Y. Liao & F. Fang. 2009. Danio quagga, a new species of striped danio from western Myanmar (Teleostei: Cyprinidae). Ichthyological Exploration of Freshwaters, 20: 193-199. Open Access PDF

Image credits:
Map from the NRM Ichthyology Collection online database, using Google Maps
Danio quagga and stream: Sven O kullander, CC-BY-NC

Equus quagga: Muhammad Mahdi Karim, from Wikimedia Commons, GNU FDL 1.2

Fish from nowhere

Yesterday I mentioned briefly the leopard danio, a small golden fish full of dark spots, apparently a color mutation in the zebrafish Danio rerio, but described in 1963 as a species on its own with the name Brachydanio frankei. The leopard danio is a popular aquarium fish in its own right, which keeps its colors but does not differ in behaviour or size from the zebrafish, and hybridises freely with zebrafish. When it first appeared in the aquarium trade, its origin in the wild was unknown. That should have called for some caution ... On the other hand, who could believe other than that the differences in colour pattern was a strong indicator of species distinctness?

Spotted danios are known from the wild, however. There is Danio kyathit from northern Myanmar, in which the spots are more or less irregularly arranged in rows, and many morphological characters distinguish it from other species of Danio. Described by Fang in 1998, based on four specimens she collected herself, she also included two specimens collected in the 1920s that were not spotted but striped. There was simply no way of distinguishing the striped and spotted kyathit other than by colour pattern, and because the rows of spots are merely broken up horizontal stripes, there was room for considering intraspecific variation. How different conclusions can be once you know a little more about the group you are working with!

Here is an image of Danio kyathit, photographed by Fang Fang.


The other spotted danio has no scientific name yet. It is a small fish, similar to Danio rerio but with large spots on the side. It is already available in the aquarium trade where it is called Danio sp. Burma. Will anyone dare to describe it? Is there a striped counterpart already available among the many supposed synonyms of Danio rerio??

A real sunshine story is the that of the "Odessa barb", one of the major aquarium fish species, and belonging to the large family of cyprinid fishes. Males are marked by a stunning, glowing, deep, exquisitely brilliant red band along the side, and contrasting black spots in the dorsal, anal, and pelvic fins. Females are less colourful. It is or relatively small size, less than 5 cm, and easy to reproduce in aquarium.

The early aquarium history of the “Odessa barb” is not well documented. In 1973, Russian aquarist Dazkewitsch wrote that it originated from a market, not stated where, and arrived in Odessa, Ukraine, in 1971, soon being cultivated in Moscow. So it was named "Odessa barb" although quite evidently a South Asian species. It was a confusing time, a time for much speculation among American and European aquarists, and no information from Ukraine. And how come a small aquarium fish, soon of world fame could first be found in Ukraine, at the time part of the Soviet Union and with no aquarium fish import? Maybe it was also a "form" of some kind, like the leopard danio? Strangely, nobody got the idea this time to describe the new fish as a new species!

So, things remained for 30 years till Frank Schäfer in 2001, working for the German wholesale aquarium fish importer Glaser reported having found the "Odessa barb" in an importation from Myanmar.

Wow! And I and my colleague Ralf Britz (yes, that's him with the vampire fish), missed it totally on our collecting trip in Myanmar just a little before, in 1998, crossing the country from Yangon in the south north to the foothills of the Himalayas in Putao.

Well, there was still no precise locality. And Ralf then found the fish in 2003, near Mandalay. So, it exists in nature, we know where, and last year we got it described. We named it Puntius padamya. Padamya is the Burmese word for ruby. The ruby barb of aquarists, however, is Puntius nigrofasciatus from Sri Lanka. The description is available online as an Open Access resource from the Electronic Journal of Ichthyology.

The "Odessa barb" freshly collected in the wild, a bit pale in the photo tank. Photograph by Ritva Roesler, from Kullander & Britz (2008: Electronic Journal of Ichthyology, 4: 56-66):


And the stately preserved holotype of Puntius padamya:


The lessons, if any, are: Don't name fish known only from the aquarium trade. Be patient. And, give nice names to nice fish.