Category Archives: Danios

Northern glowlights

My kitchen window

My kitchen window

Winter in Sweden, and that means darkness, cold, and snow covering all and everything. No wonder every window is lit, day and night, with glowing stars, moons, snowflakes, menorahs, or the new fashion little reindeer or bears lit by led from inside. Without all those warming winter lights darkness would bend our backs, and we would get swept away by depression. Or maybe not.

Nevertheless, I would like to take this window view to remind myself of another northern glowlight, recently named Dano flagrans. It is a little fish from warmer waters. From where it hails, however,  you can actually view the snow of the eastern outcrops of the Himalayas. It is certainly the most septentrional of the Myanmar Danio, but rivalled, apparently defeated in northerliness by Danio dangila which occurs in the Brahmaputra basin in India up to the Dibru River. No other species of Danio reaches so far north.

Looking northeast from Putao

Looking norwest from Putao

The scientific history of Danio flagrans begins in 1988, when I, in the company of Ralf Britz and our guide Thein Win arrived in Putao, the northernmost major city in Myanmar. Putao is close to the Chinese and Indian borders, on hills forming the headwaters of the Mali Hka, major tributary of the Ayeyarwaddy River which then runs through Myanmar as one big muddy aorta. Up in the Mali Hka, however, the water is clear, at least in the dry season, not very deep, and the river beds paved with stones and rocks. The fish fauna of northern Myanmar mountain streams is little known. Transportation in the area is relatively complicated, and a lot remains to be done up there in terms of ichthyological exploration.

Mali Hka in Putao

Mali Hka in Putao

Back to our story, our little team was quartered in the military camp and we immediately set out to fish, having only two full days at disposal. The Mali Hka itself was too big for fishing, although alright for sightseeing, but around the regiment there were several small streams with low water and convenient for seine and handnets. The streams were shallow, the water was clear, rather cool, and fish were plenty. Here we found Badis pyema which was promptly described already in 2002, and Puntius tiantian in 2005, but other fish have lasted longer to be worked up. Walking along one of the streams, we switched direction to follow a tickle of water, almost no water, coming down the left bank hill, and in there were little skittish fish, almost invisible against the beige earth and seen only as moving shadows. A number of them, certainly Danio choprae – such was the field identification – came into formalin and one made it to a tube of alcohol. Neither Ralf nor I was into danios at the time, so the fish we just hoped would be useful for Fang, and  we went on happily, catching Badis pyema and similar fish that had more of our attention those days.

Fresh collected northern glowlight danio, Putao 1998

Fresh collected northern glowlight danio, Putao 1998

One of the Putao danios was photographed but this was in times of film photography, with no immediate quality check, and much is to be regretted by the quality of the shot. Publishable it is not, but here it can be showed off as the first image ever taken of a Danio flagrans. The alcohol specimen was sequenced and appeared in a phylogenetic tree as Danio choprae (Fang et al., 2009), and by that time noone had looked at it closely (we had other specimens, true D. choprae for the morphological data). Time passed on. This was one species that Fang never worked on, but which obviously was somewhat different from the other samples of D. choprae, and I decided to give it a go in the Spring of 2012. The manuscript was already in hand as I again met Ralf in Belgium and we spoke about past achievements and plans for the future. As he had more of the danios from Putao from a later trip, and more D. choprae, he insisted that I include this material, and so it was. The paper had to be done from almost scratch but Ralf’s material certainly improved a lot on the description and conclusions. The description of Danio flagrans, the northern glowlight danio, eventually appeared in late 2012, 14 years after its discovery (Kullander, 2012). Incidentally, it is my first own danio paper, and it was fun to do. It was enjoyable in particular, because Danio flagrans and its sister species Danio choprae do not differ only in colour (in fact they are very similar in colours), but also present some very solid morphometric and meristic differences. I am otherwise much too used to cichlid species that differ by just some pigment spot. Danio flagrans has a shorter anal fin, with less fin-rays, and longer caudal peduncle compared to Danio choprae. Perhaps this relates to their environment. Danio choprae lives more to the south, near Myitkyina, and in warmer habitats; Danio flagrans in cool hillstreams. Beware that these species may not be correctly identified in the shops. Danio choprae, the glowlight danio may appear in the market as northern glowlights, a more expensive fish. I know, three of the false northerns are swimming in a tank in my garage. These changelings are beautiful fish decorated with orange stripes. Unfortunately, they never stay still, but are constantly on the move, and they move fast, so a good view of them remains an illusion of expectation. This brings me, by association, to the conclusion of this post: Besides lights in the windows, there is one more resource to overcome winter gloom. An aquarium with beautiful fishes (all fish are beautiful). Always something to see, to learn, to enjoy.



Fang, F., M. Norén, T.Y. Liao, M. Källersjö & S.O. Kullander. 2009. Molecular phylogenetic interrelationships of the South Asian cyprinid genera Danio, Devario and Microrasbora (Teleostei, Cyprinidae, Danioninae). Zoologica Scripta, 38: 237-256.

Kullander, S.O. 2012. Description of Danio flagrans, and redescription of D. choprae, two closely related species from the Ayeyarwaddy River drainage in northern Myanmar (Teleostei: Cyprinidae). Ichthyological Exploration of Freshwaters 23: 245-262. Open Access PDF from Verlag Dr. Friedrich Pfeil.

Kullander, S.O. & R. Britz. 2002. Revision of the family Badidae (Teleostei: Perciformes), with description of a new genus and ten new species. Ichthyological Exploration of Freshwaters, 13: 295-372.

Kullander, S.O. & F. Fang. 2005. Two new species of Puntius from northern Myanmar (Teleostei: Cyprinidae). Copeia, 2005: 290-302. Open Access PDF.

Photos: Sven O Kullander, CC-BY-NC

Day 1, 2011

As the snow whirls around and the cold fills up the atmosphere, the new year brings a welcome day off to be taken care of. Dough is rising and breakfast bread will be served in an hour or so. Family is sleeping, stoned by the unusual late hours to sit through the paradox of a year and decade shift without anything really happening. Only computers worldwide automatically shifting display date, steadfast from Australia westwards. It takes 24 hours to shift from one day to another, or does it?

The past autumn proved hectic to the limit of sustainability and blogging plummeted, so there is something to be caught up on.  Most of last year wasn’t in the plus column, however, so there is a lot to be expected from this one. The highlights of the past twelve months that come to mind spontaneously were:

The FishBase Symposium 2010 in Stockholm, October 18, featuring a fantastic series of talks by highly successful, competent and enthusiastic personality scientists covering all of what it takes to be a fish systematist, not least the field work and the need for specimens, not only tissue samples to do systematics, Melanie Stiassny, Maurice Kottelat, Tan Heok Hui, Richard Pyle, Jörg Freyhof, Anthony Gill, moderated by one more star, Ralf Britz. The audicence enjoyed the show tremendeously, and so did I. There is a report to download, most of it in Swedish, but there is always Google Translate.

Te Yu Liao’s PhD dissertation defence with Paul Skelton as opponent, 18 November. Te Yu has been with us at NRM since 2006 working on a revision of Rasbora and similar fishes. It has resulted in several phylogenetic studies, and several morepapers, altogether seven publications,  included in the dissertation (A phylogenetic analysis of the rasborins (Cyprinidae: Danioninae: Rasborini)) but still to be published. These papers provide a new framework for danionine systematics and are based on both morphology and molecules. Some of the papers are:

  • Fang, F., M. Norén, T.Y. Liao, M. Källersjö & S.O. Kullander. 2009. Molecular phylogenetic interrelationships of the South Asian cyprinid genera Danio, Devario and Microrasbora (Teleostei, Cyprinidae, Danioninae). Zoologica Scripta, 38: 237-256.
  • Liao, T.Y., S.O. Kullander & F. Fang. 2010. Phylogenetic analysis of the genus Rasbora (Teleostei: Cyprinidae). Zoologica Scripta, 39:155-176.
  • Pramod, P.K., F. Fang, K. Rema Devi, T.-Y. Liao, T.J. Indra, K.S. Jameela Beevi & S.O. Kullander. 2010. Betadevario ramachandrani, a new danionine genus and species from the Western Ghats of India (Teleostei: Cyprinidae: Danioninae). Zootaxa, 2519: 31-47.

Peter Cottle’s book about danios (Danios and Devarios) came out in December, and made a great holiday gift. The title of the foreword (which I wrote …) summarises the opus: Passion. I will get back to this book and others, but suspecting the edition may be somewhat limited, I would recommend you to get your copy now …

What is up now:

There will be more danionine papers, several already in press

A long series of cichlid papers are in an advanced state, both on African and South American cichlids

FishBase will organise three meetings this year: the annual FishBase Minisymposium with the FishBase Consortium, the annual Swedish FishBase symposium, and triannual Artedi Lectures

The first volume about fish in The Encyclopedia of the Swedish Flora and Fauna series will be published in May or so. This volume covers all species of chordates occurring in Sweden from cephalochordates to chondrichthyans, authored by me, Thomas Stach (tunicates) and Henning Blom (introductions to chordates and vertebrates). The illustrations, however, may be the major reason to look forward to this book. They are all new, and all the Swedish fishes are superbly illustrated from scratch by Linda Nyman and Karl Jilg (I haven’t seen the tunicate illustrations).

And I will go to Iceland. All my life I strived to go south, to warmth, but my former student, Georg Friðriksson, who is now an ichthyologist with the Náttúruminjasafn Íslands, has assured me that Iceland is not covered with ice and snow in the summer (or has he? May have to ask again). They have fantastic fish, all kinds of ecophenotypes of char, but also sticklebacks.

As you can see, 2011 looks all bright, new, and worth living.

In the media: WWF and Danio tinwini

Danio tinwini

Danio tinwini, living specimen. Photo Sven O Kullander CC-BY-NC

The little fish hit the headlines today, in WWF‘s press release on their report on species described from South East Asia in 2009. Although the cover honours a radically crimson dracula fish (Danionella dracula), page 11 is devoted to Danio tinwini, subject of a longer treatise in this irregular blog.

Of course there are other rare or spectacular things in that report which is well worth downloading. WWF has counted 145 new species as described from what they call the Greater Mekong area. Twenty-six species are fish, four of them from my lab:

  • Danio aesculapii Kullander & Fang
  • Danio quagga Kullander, Liao & Fang
  • Danio tinwini Kullander & Fang
  • Devario xyrops Fang & Kullander

Of course, it is nice of WWF to highlight the species diversity in the region, and there may very well be another 26 species described every year, on and on. It is also welcome that WWF and others are putting funds and energy into conservation efforts of critical areas or whole ecosystems. This work is badly needed; every living thing in the tropics is at risk, and a greater risk every day. It is unfortunate, however, that practically all those discoveries are done with a minimum of funding only, or just out of devotion.  Taxonomy and discovery is underfunded. Where is the money for the discovery, description, and mapping of all the unknown biodiversity?

On October 18, FishBase Sweden organises its annual Symposium. This time the theme is discovery. The importance of exploring new areas, and discovering new species and analysing the evolutionary history of those life forms.  The programme is available from the FishBase Sweden website.

A very strange danio

Every well informed freshwater ichthyologist is familiar with forum.  Petfrd does not easily translate to Singapore Cichlid Community, which seems to be the patron of the site, but I have no clue to what petfrd could mean. The forum has several sections, and postings are enthusiastic and often with beautiful images of habitats or fresh collected fish contributed by local aquarists from all over southern Asia (and others, sure) . Ng Heok Hee moderates a section about scientific literature and usually is abreast of locating new papers about cichlids or Asian fishes. So, here is the secret about staying informed: daily visits to!

Betadevario ramachandrani in the aquarium. Photo (c) Beta Mahatvaraj

In January 2008, information and photos were posted of  what looked like a danio but sufficiently different not to be ignored as ‘one more…’. ‘Beta’, with a sad smiley reported that his fish were in the freezer. Fang immediately got in contact with ‘Beta’, whose name is actually Beta Mahatvaraj, enthusiastic Indian aquarist. His five frozen fish were preserved in ethanol and formalin and shipped to us. They weren’t really fresh, and the colour somewhat faded, but still all anatomy and DNA could be extracted from hem. Fang started writing up a description and gave it a manuscript name, ‘Betadevario longibarbis’.

It wasn’t a Danio as some of the first reports had it. It was more like a Devario, with those longitudinal depressions above each eye filled with sensory organs, characterizing Devario and Chela. But still not looking like a Devario, above all because of the long barbels, but also with regard to the coloration, which is unique among danios, with a light band along the middle of the side, and dark abdominal sides. Devario typically have very short barbels or they are missing completely, whereas most Danio have long barbels.

Actually, Devario is a speciose genus with more than 50 species, many still undescribed, and there is considerable variation in shape and colour pattern among them. They never have long barbels, though.

Since everything takes long time for us (the Cichla revision published 2006 took 17 years, and other papers not published were written in the 1980s, to give you a hint), it wasn’t unexpected to learn in 2009 that an Indian team was also working with the same species, and also with very few specimens. It took till December 2009 before we established contact and things were arranged for a collaborative effort to get the fish described. In the meantime much more material had become available, and indeed there were already numerous presentations of the fish on the web, e.g., in PFK  and in several Indian news sites.  Collaborating meant we could provide a fairly complete review of the new species with habitat data and image, live colour photo, and molecular and morphological phylogenetic analysis, better than individual papers would have been.  Betadevario got the species epithet ramachandrani for A. Ramachandran. Our molecular and morphological analyses differ with regard to its placement in the phylogenetic tree, but it is certainly a very basal taxon among Devario like danios, and we have more confidence in the molecular data which places it as sister group to other Devario.

Why not make it a Devario then? A good question for any genus, and will never have a good answer for all who come up with it. In this case we reasoned that the molecular analysis provided better clarity. The morphological dataset was good for distinguishing Devario and Danio, but not for resolving relationships within Devario. We have to work a lot more on that. And we are doing it, with both morphology and molecules. Betadevario presents a unique colour pattern and long barbels to distinguish it from all Devario (including Inlecypris),  providing a morphological justification for the genus.

Betadevario ramachandrani immediately after capture. Photo (c) P.K. Pramod.

The largest specimens measured about 60 mm. There are no characters to distinguish males and females, except the tubercles on the pectoral fin in males, a secondary sex indicator shared with most Danio and Devario. Information on live colours are not in concert. The live fish on Beta Mahatvaraj’s image are golden and brown/blackish, whereas the illustration by P.K. Pramod shows a a fish with a blue stripe along the side and lemon yellow fins. It will be interesting to see Betadevario alive sometime. It does not look like it will be a big aquarium fish, but who can say. It is so far known only from a small mountain stream in the Western Ghats, with relatively cool water, and may be expected to be sensitive to transportation.

Betadevario ramachandrani is known only from a very small area in the Western Ghats, the mountain range along the western coast of India, where it lives in fast running clear waters in the forest.

You don’t need a longer story here. The full description of Betadevario ramachandrani with habitat image, trees, and other details is available free to download from the Zootaxa website.


Pramod, P.K., F. Fang, K. Rema Devi, T.-Y. Liao, T.J. Indra, K.S. Jameela Beevi & S. O. Kullander. 2010. Betadevario ramachandrani, a new danionine genus and species from the Western Ghats of India (Teleostei: Cyprinidae: Danioninae). Zootaxa, 2519: 31-47.


Thanks to Beta Mahatvaraj and P.K. Pramod for making the images of live fish available.

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!

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.

Zebrafish in spirits

Zebrafish (Danio rerio) are probably the most important fish for understanding humans. They are small fish, 2-3 cm long and native to India, Bangladesh, and Pakistan. Most conspicuous about them is the contrasted coloration with alternating blue and white horizontal stripes, even extending onto the caudal fin. That means they are horizontal where zebras are vertical. Otherwise there are no similarities 🙂

Zebrafish occur in many places in India, in the north in the Indus, Ganga, and Brahmaputra as well as in Kerala in the south, but appear uniform in color pattern and other morphology. They live in schools in different habitats, and are often collected in large numbers. As aquarium fish they are hardy, easy to breed, and prolific.

The distinctive colour pattern, which can be genetically altered, ease of keeping, and the fast generation time contribute to zebrafish status as a so-called model organism, which developmental biologists use to study the development and inheritance of various structures. Recently also, zebrafish researchers have been helped by improved understanding of the systematics of the group of fishes to which zebrafish belong, so that structures can be studied comparatively in closely related species.

Here is a dead zebrafish in alcohol from Assam, India. Not very colourful, but useful for taxonomic studies.

I just spent two days writing a description of a new species that I and my student Te Yu Liao collected last year (about this time) in Myanmar. There are many species of fishes closely related to the zebrafish. Thirteen species have been named in the genus Danio, and at least ten more species remain to be described. Most fascinating among the zebrafish relatives, is the leopard danio, which turned up in aquarium circles in Czechoslovakia in the 1960s and was described as a new species with the name Brachydanio frankei. This form, with small dark spots all over the body and fins, has never been found in the wild. It is probably a mutant of zebrafish, differing only in the irregular colour pattern. The genus, however, includes species that are spotted for real.

I will come back to fish species that only exist in the aquarium trade later. Let us round off the day with some zebrafish entertainment.

If you need just an overview of zebrafish, with the basic data, try Fishbase.

Wikipedia insists on being very technical about zebrafish

These developing zebrafish embryos are just irresistible:

The Wolfgang Driever Lab at the University of Freiburg has still images so you can track all the details at different stages. Click the image (from their website) to enter the zebrafish anatomy:

And then there is an enthusiasts’s website with images of various zebrafish-like species, Pete Cottle’s Danios and Devarios.