Please note, this article was originally posted elsewhere on 14 March, 2013. I figured my catfish friends on PCF would enjoy reading this too. I especially would like to thank Silurus- without whom this article wouldn't have been possible.
Goonch. Devil catfish. Bagarius yarrelli. Whatever you may choose to call it, these monsters are unmistakeable. These enigmatic fish exploded into the cultural awareness of the masses with the the airing of the River Monsters episode "Killer Catfish" on April 12, 2009. The concept of a seven foot long, two hundred pound catfish with the teeth of a shark, that kills and eats people is a fascinating concept indeed.
The current all tackle world record goonch, 191 pounds 13 ounces, caught by Jakub Vagner on the Ramganga River in India.
The current other methods world record goonch, 231 pounds eight ounces, caught by netting on the Jamuna River in Bangladesh.
There are further reports of goonch catfish being caught with body weight up to 529 pounds (as supposedly caught on the Kushiyara River, which is also in Bangladesh), but these claims are anecdotal and unreliable, and should be considered dubious as best.
When one combines the huge size these fish can achieve with their ferocious reputation, it is hardly a surprise that they have become an incredibly sought after type of fish in the fish keeping hobby. This begs the question however, just what kind of fish are we seeing imported? How can one correctly and consistently identify what kind of goonch just showed up in that little brown box at their door? I made it my goal to answer that question, and I have spent the past several months trying, to my great consternation, to answer that question. As nearly as I can tell, there is only one answer to the question of identifying your goonch:
You cannot.
That is right, it seems as though we, the hobbyists, cannot positively identify our goonches in most cases. Why? Because even the biologists who work with them cannot positively identify exactly which fish are which. This is because the current revision to the genus from which we hobbyists are drawing our conclusions is thirty years old. The data is dated and the genus is in dire need of revision. What this means is that the current classification of these fish is very likely wrong. Dr. Ng, (one of the gentlemen who wrote the paper that described B. rutilus) who has been incredibly helpful in my search for data, agrees with this sentiment. If not for his assistance and guidance, I would likely not have been able to prepare this post today.
The current understanding of the fishes in the genus Bagarius after Roberts (1983) is as follows:
Species Location Size
Bagarius yarrelli India and southeast Asia Huge, 6'+
Bagarius rutilus Southeast Asia No more than 4'
Bagarius suchus Southeast Asia No more than 3'
Bagarius bagarius Southeast Asia 8"
Based on the currently available data, this appears to be incorrect. Roberts noted that there was a huge variability in the color of B. yarrelli and the morphology of the gill rakers in B. yarrelli and B. bagarius.
Based on the very minor differences in the morphology of a 415mm specimen that Roberts would have called B. yarrelli, Ng & Kottelat (2000) described a new species, what we now know as Bagarius rutilus. There are many minor differences that distinguish rutilus from yarrelli that are not diagnosed by Robert's fin origin and vertebrae count method, mostly body proportions and tubercle locations. There are however two striking differences that even the hobbyist can spot to identify a rutilus from it's congeners: elliptical eyes and when larger, orange fin coloration. Rutilus is one species a hobbyist could potentially correctly identify.
The holotype of Bagarius rutilus, courtesy of Dr. Ng and used with permission. Note: this specimen's color is stained a yellowish hue due to preservative.
Bagarius yarrelli as described by Roberts, 1983.
In the above images, one cannot help but notice a striking similarity between Robert's yarrelli from the Meghna River in Bangladesh to Ng & Kottelat's rutilus; especially notable are the elliptical eyes and lack of spots on both fish.
But wait, the convolution of the phylogeny of Bagarius does not stop with the schism of rutilus into a unique species. It only gets worse...
How do we explain the fact that Bagarius yarrelli appears to live in three distinct biomes throughout Indochina: swift, fast, cold rivers in northern India; low, wide, hot rivers and floodplains in southern India and large, deep powerful tropical rivers in southeast Asia? One possible explanation is that there are two or even three separate species that comprise what is now known as "Bagarius yarrelli".
The primary species that we are all familiar with; the charismatic, fearsome and famous giant goonches of the cold waters of northern India should be Bagarius bagarius. This is due to Robert's splitting B. yarrelli off of B. bagarius based on the morphological similarities of the originally described B. bagarius of India (Hamilton-Buchanan, 1823) to the at that time undescribed dwarf goonch species from southeast Asia. Roberts noted that not all of the Indian specimens that he examined met the fin origin description of B. bagarius. Dr. Ng informs me that ithe explanation for this inconsistency could be due to the possibility of two separate species of Bagarius in India: the familiar, giant northern species, which should be known as B. bagarius as written by Hamilton-Buchanan and a separate, large, southern species which fits the alternate description of Robert's B. yarrelli. It will however take a comprehensive review of material to clarify this issue.
What of the large, "dalmatian-spotted" specimens from southeast Asia and Indonesia that in some places live along side of Bagarius rutilus? Well, there was an answer to that. That answer came in the form of Bagarius lica, as described by Dr. Walter Volz in 1903. B. lica was later rolled into "yarrelli" (really B. bagarius) by Roberts based on vertebral morphology, fin rays and coloration. As evidenced by Robert's failure to properly classify rutilus, which he also considered to be yarrelli , I consider the synonymy of lica to "yarrelli" (really B. bagarius) to be dubious. There are a number of morphological differences between the southeast Asia variety of "yarrelli" (probably lica) and the northern India variety of "yarrelli" (really B. bagarius) which, when coupled with the difference in their habitat, strongly indicates separate species.
Dwarf goonch, via Google.
So what of the dwarf goonches? As it stands, it appears as if they don't have a proper scientific name. If Roberts was mistaken in his classification of B. bagarius as a dwarf species when it is in fact the giant species, then this means that the assignment of the name B. bagarius to the dwarf variety is invalid. The dwarf variety still appears to be a valid species and has an acceptable description, but the name which was used to describe it belongs to a separate, previously described population of goonch. This leaves Bagarius cf. "dwarf" nameless.
Bagarius suchus, via Google.
The one species of goonch that can actually be identified by a hobbyist is Bagarius suchus. This medium sized, flattened goonch is quite unique in the genus and is quite easily identified by even the untrained eye.
Based on the available evidence, I feel that there are six species of goonch catfish:
Species Location Size
B. bagarius Northern India Enormous, 7' or so
B. yarrelli Southern India 5-6'
B. lica Southeast Asia 4-6'
B. rutilus Southeast Asia No more than 4'
B. suchus Southeast Asia No more than 3'
B. cf. "dwarf" Southeast Asia 8"
Of course I am still a student and am in no position to attempt a proper revision of Bagarius. Yet. My intention with this post is to simply try to clarify why it is that it is so hard to properly identify which species of Bagarius you have. The habit of exporters to send everything Stateside under the name B. yarrelli, combined with the relative lack of awareness of rutilus and the dated taxonomy of the genus makes it, in my humble opinion, nearly impossible to properly classify what species of fish we own.
Acknowledgements-
I would like to particularly thank Dr. Ng for his assistance in this matter. For providing me with information, ideas and the image of the rutilus holotype. Thank you sir.
I would also like to thank MFK members Estarego8, Egon, Evilartform and wayne the pain for granting me permission to use images of their fish in my guide, which due to the obvious difficulties facing me, I was not able to complete.
References-
Ng, H. & Kottelat, M. (2000). Descriptions of three new species of catfishes
(Teleostei: Akysidae and Sisoridae) from Laos and Vietnam. Journal of South Asian Natural History 5 (1): 7-15.
Ng, H. (2013). Personal correspondence.
Roberts, T. (1983). Revision of the South and Southeast Asian Sisorid Catfish Genus Bagarius , with Description of a New Species from the Mekong. Copeia, 1983 (2): 435-445.
Volz, W. (1903). New Fish from Sumatra. Zoological Gazette, 26 (703): 553-559.
Volz, W. (1903). Fish of Sumatra. Zoological Annuals. Department for Systematic, Geography and Biology of the Animals (Jena), 19: 347-419.
