My Experience Mixing Tigrinus (& why not to do it) (dismissing the golden tigrinus)

[Jush]

Hi, I thought I'd write a post on mixing Tigrinus, because many people adore these catfish & would love to mix it like Redtails, Tigershovelnoses & other common types of Catfish, but I want to share my experience & why I advise you NOT to mix them.

Story​

So it starts with me purchasing my first Tigrinus which was about 3-4", and I'd already fallen in love with the catfish before purchasing it. I loved it that much I went on the hunt for more, as I felt I had a bigger than usual wallet at the time, lol. I found another a few weeks later at which point my current Tigrinus is about 5" & had lost all the typical redness they have & had some almost golden flake developing. The one I purchased was around 3-4" also, so I deemed it would be ok to mix them, although I was advised against doing so, it actually worked at first. They kept their own territories, and if one crossed into another side of the tank, they'd almost go stiff & flick at each other then dart back to their side of the tank. All going well, its working.... for maybe 3weeks or so. I purchased a Fly River Turtle so the tank they were growing out in is now for the Turtle, so I actually moved them into a larger space, which is where it didn't work. Now about 6" & 4-5" the larger one of the two was constantly not allowing the smaller one's threadfin to grow, which is obviously one of the main draws for Tigrinus Catfish, which was the first sign as well as more flicking & aggression. As days passed by the larger one would rarely swim up the side & mainly sit on the bottom (which I presume he claimed as his territory) eating all the food while the smaller one just swam up the glass despite any effort I did to give it food, it wouldn't eat. I gave it about 2 weeks before deciding to move it to another tank, and there on I have now sold it. thebiggerthebetter did advise me in the beginning, and as time went on, it worked & in turn didn't work. I don't doubt that a group will work like Victor has displayed however it has also been mentioned that living in such close conditions could well affect their welfare & life expectancy. I see this situation similar to mixing Arowanas in which the more the better alongside the more space the better, I believe if a tank/pond with an abnormal size footprint such as 12x6x2 was provided, a group of 4+ could live together perfectly well, but as my specimens were babies, I provided them what I thought was adequate, which was at first a 3x1.5x2 footprint which moved up to 3x2x2 footprint which in turn didn't work even at small size. Mixing Tigrinus is a thing I would love to do successfully, maybe when the day comes that £2000 or so is lying around waiting to be spent on a group of 8+ of these fish, but because every specimen is wild-caught & to my belief, there is no documented success on captive breeding grabbing 8+ of these seasonal animals will not only be hard, but expensive & providing them with the correct environment from baby size which is probably around 6x2x2 with plenty of hides, visual barriers (which I didn't provide other than 1 3stacked tube) it is possible, and Victor has proven it. I'd advise against mixing smaller number groups such as 2-4fish, and if the day every comes focus on getting a minimum of 6, with the more the better, but obviously these are not the easiest catfish to keep requiring more expert care with not only pristine water as all fish require but a carefully balanced & selected diet to prevent them bloating which easily happens, and more that can be obtained the more space that is required.

My Tigrinus I have decided to keep...


Dismissing the Golden Tigrinus​

Recently many batches of Tigrinus have entered the U.S.A & Europe & are being sold for what I can only presume are higher prices compared to normal tigrinus, but these are NO different from any tigrinus & still follow the same sp of Brachyplatystoma tigrinum, this is just a difference in quality, catch location, diet or many of the other common factors. Time will tell if this goldish sticks with the fish or fades out, I personally think it looks good & as it grows it will fade out, but everyone has an opinion. If it didn't fade out it would definitely make a cracking Tigrinus & spice up the colour & look of the fish. You can also probably gather from the photo that the bars of the Tigrinus seem bolder & more pronounced, I believe this specimen is around 8" & the photo of my personal fish is about 7" & the clear difference in bars is obvious. Tigrinus obviously develope different bars from others & no 2 are alike, similar to Datnoid barring however it's very common to get fork or 4 bars which are near-on identical, this difference could be based also on the diet, quality, catch location, lighting, tank background & many of the other common factors.

The Golden Tigrinus (photo from Chicago Stingrays)


​

- my statement about all wild caught comes from a Facebook question I asked, in which people from all around the world contributed their answer & around 90% said all wild-caught.

 

[necrocanis]

Thanks for the write-up on your experiences of keeping this gorgeous species. I have never been able to keep them. Back when I was actively hoarding catfish I wanted to but didn't want to stick one in with other large catfish that would stress it out. Also at the time I didn't have $1000+ to spend on one but it seems over the years the prices have dropped drastically. Also now you can get smaller ones. They must have located spawning grounds

 

[Jush]

Thanks for the write-up on your experiences of keeping this gorgeous species. I have never been able to keep them. Back when I was actively hoarding catfish I wanted to but didn't want to stick one in with other large catfish that would stress it out. Also at the time I didn't have $1000+ to spend on one but it seems over the years the prices have dropped drastically. Also now you can get smaller ones. They must have located spawning grounds

I believe they get them from the shallows in the mid-year season & they enter the market around Sepetember.

 

[Chicxulub]

Great write up! I've long been on record that when dealing with a rare and expensive fish like this, it's always best to try to build a community around your crown jewel, rather than stuffing as many cool things into the same box as possible. Obviously some can make it work, but as your experience shows, it doesn't always.

As to the golden tigs, there's something there. In the same was as we have a high variety of pattern and color variation in the closely related B. juruense, the wild caught tigs seem to display similar phenotypic variability in their patterning. I like to refer to the patterns displayed in these species as striped, slanted and mosaic. Yours is what I'd call striped, the "golden" fish is what I'd call mosaic. At the risk of leaving that half discussed however, I realize that I'm digressing pretty badly.

All that being said, I don't think the color variability displayed in both jurs and tigs (nevermind many other South American species that lose their color in captivity) is genetic- I think it's environmental.

I've got several papers saved on my computer (I'm on my phone at the moment) that support my hypothesis that SA fish have trace quantities of chemical supplementation that is absent in captivity such as carotenoids and xanthophylls that work their way up the food web from algae and planktonic trophic producers all the way to large predators like Brachyplatystoma, where the colors may be expressed.

This is only part of what I think is happening, with water parameters coming into play as well.

I hope to proof this idea sometime soon.

In short, I think the golden tigs and jurs display such colors through environmental factors instead of OR in addition to purely genetic ones.

 

[Jush]

Great write up! I've long been on record that when dealing with a rare and expensive fish like this, it's always best to try to build a community around your crown jewel, rather than stuffing as many cool things into the same box as possible. Obviously some can make it work, but as your experience shows, it doesn't always.

As to the golden tigs, there's something there. In the same was as we have a high variety of pattern and color variation in the closely related B. juruense, the wild caught tigs seem to display similar phenotypic variability in their patterning. I like to refer to the patterns displayed in these species as striped, slanted and mosaic. Yours is what I'd call striped, the "golden" fish is what I'd call mosaic. At the risk of leaving that half discussed however, I realize that I'm digressing pretty badly.

All that being said, I don't think the color variability displayed in both jurs and tigs (nevermind many other South American species that lose their color in captivity) is genetic- I think it's environmental.

I've got several papers saved on my computer (I'm on my phone at the moment) that support my hypothesis that SA fish have trace quantities of chemical supplementation that is absent in captivity such as carotenoids and xanthophylls that work their way up the food web from algae and planktonic trophic producers all the way to large predators like Brachyplatystoma, where the colors may be expressed.

This is only part of what I think is happening, with water parameters coming into play as well.

I hope to proof this idea sometime soon.

In short, I think the golden tigs and jurs display such colors through environmental factors instead of OR in addition to purely genetic ones.

I believe all Tigs are wild-caught, or at least that's what I gathered from my own research & general question on Facebook which had worldwide hobbyists posting their opinions, apparently captive breeding has been attempted but with little-to-no success. I started out with the fact we never see Tigrinus as a trophy fish someone has caught in the wild, like we see Arapaima, Redtails, Tigershovelnose, etc, but we don't see a happy angler holding a Tigrinus up, and this is apparently due to their natural area which is heavily cartel patrolled & also has tribes & some complex laws. So the Golden Tigrinus, which is the same fish, could be based on catch location, and obviously the chemicals which work their way into the fishes diet or many of the other factors which could be the lighting. My little Tig had a little bit of golden flaking when he was on Brown(ish) substrate, but since moving onto lighter, white substrate he is a typical tig pattern.

I agree with you on the mosaic pattern & stripe pattern, I personally prefer the thicker bars on the smaller specimens, but I'd love to see one of these "golden tigrinus" large, because I can't really imagine the mosaic pattern or golden flake lasting. It's similar to the morphs we get with Juru with the flashes who don't even show visible stripes but then other Juru which are very dark with slightly-lighter bars.

I've always wondered if Juru is a tigrinus "underneath" which is either morphed, or caught in a different location or other environmental differences, I know they both follow the same family of Brachyplatystoma (or at least I think they do, never kept a Juru) I've only ever seen 1 Juru in real life though, which was a 4" specimen in a dim-lit tank, so I couldn't gauge the difference well, but I'm aware Juru typically hit 3-4ft whereas Tigs hit 2-3ft which maybe dismisses the question I've already had before I've even finished asking it.

 

[necrocanis]

I believe all Tigs are wild-caught, or at least that's what I gathered from my own research & general question on Facebook which had worldwide hobbyists posting their opinions, apparently captive breeding has been attempted but with little-to-no success. I started out with the fact we never see Tigrinus as a trophy fish someone has caught in the wild, like we see Arapaima, Redtails, Tigershovelnose, etc, but we don't see a happy angler holding a Tigrinus up, and this is apparently due to their natural area which is heavily cartel patrolled & also has tribes & some complex laws. So the Golden Tigrinus, which is the same fish, could be based on catch location, and obviously the chemicals which work their way into the fishes diet or many of the other factors which could be the lighting. My little Tig had a little bit of golden flaking when he was on Brown(ish) substrate, but since moving onto lighter, white substrate he is a typical tig pattern.

I agree with you on the mosaic pattern & stripe pattern, I personally prefer the thicker bars on the smaller specimens, but I'd love to see one of these "golden tigrinus" large, because I can't really imagine the mosaic pattern or golden flake lasting. It's similar to the morphs we get with Juru with the flashes who don't even show visible stripes but then other Juru which are very dark with slightly-lighter bars.

I've always wondered if Juru is a tigrinus "underneath" which is either morphed, or caught in a different location or other environmental differences, I know they both follow the same family of Brachyplatystoma (or at least I think they do, never kept a Juru) I've only ever seen 1 Juru in real life though, which was a 4" specimen in a dim-lit tank, so I couldn't gauge the difference well, but I'm aware Juru typically hit 3-4ft whereas Tigs hit 2-3ft which maybe dismisses the question I've already had before I've even finished asking it.

I am an say for certain that tigs and jurs are separate species. Besides the studies done through phylogenics and dna testing I have also prepared the skulls of both species. For how much they look alike on the outside their anatomy was a bit different inside although both follow the Atypical anatomy of the genus Brachyplatystoma.

Jurs for instance have a broader and thicker skull than tigs. Typically a bulkier animal at the same length as well.....usually.

 

[thebiggerthebetter]

Thank you for this edifying thread.

I don't think the fact that your smaller tig stopped feeding in the new tank for a few weeks has only one explanation and that is that the bigger tig was bullying it. There easily could have been other reasons. We are so utterly helpless when our fish stop feeding or get sick - more often than not we have no clue why and usually only guess.

Chicx has been our authority on jurs and tigs, so I usually just listen to him, especially after he got all degreed up in biology

Perhaps I am off or outdated but my current belief is that jurs do not exceed 2 feet. The 4' claim on the Fishing World Records site is a case of mistaken ID, a bad lapse.

Jurs and tigs are for certain different species. Moreover, Chicx told us tigs are black fish with white markings while jurs are white fish with black markings, which carries consequences explaining why tigs stripes are so stable relative to the heavily evolving jur stripes.

This thread is the first time I hear of the "golden" variation in tigs. It smells fishy to me but time will tell, I hope. I just know the fish-keeping hobby and trade are on the leading edge of sellers pulling all sorts of tricks (and often hurting animals in the end result and giving PETA some grounds) to fool the buyers into buying "the new and the special"...

 

[Chicxulub]

necrocanis and thebiggerthebetter hit on the main points I was going to make in reply; thank you, gentlemen.

The only thing I wish to add at this point is in relation to the golden tigs.

I have seen anecdotal reports and rumors and the like of these for about a decade. I have also seen pictures of what is clearly a very large tigrinus being used occasionally in arguments about flash zebra juruense that were quite yellow. These were immediately identified as being tigrinus in the discussions at hand, but the speculation as to why they were yellow generally led to the preservatives used to fix a holotype specimen. This would be immediately met with concern as to why someone would have a chemically prepared and preserved fish available in pictures that clearly appear to be taken while fishing or at a fish market. We've never really figured out what's going on with these.

I suspect that some supplier has figured out the place where these rare pictures were taken and has acquired a few of these tigs which have now found their way into the market. I also suspect, based on the required supplementation to the diet discussed above, that these fish much like many other South American species will rapidly and irreparably lose that coloration in the hobby.

I'd like to be wrong on that.

Time will tell however. I've got ants in my pants to try to test out some of my hypotheses. 2020 should be the year when I get these experiments going.

 

[necrocanis]

necrocanis and thebiggerthebetter hit on the main points I was going to make in reply; thank you, gentlemen.

The only thing I wish to add at this point is in relation to the golden tigs.

I have seen anecdotal reports and rumors and the like of these for about a decade. I have also seen pictures of what is clearly a very large tigrinus being used occasionally in arguments about flash zebra juruense that were quite yellow. These were immediately identified as being tigrinus in the discussions at hand, but the speculation as to why they were yellow generally led to the preservatives used to fix a holotype specimen. This would be immediately met with concern as to why someone would have a chemically prepared and preserved fish available in pictures that clearly appear to be taken while fishing or at a fish market. We've never really figured out what's going on with these.

I suspect that some supplier has figured out the place where these rare pictures were taken and has acquired a few of these tigs which have now found their way into the market. I also suspect, based on the required supplementation to the diet discussed above, that these fish much like many other South American species will rapidly and irreparably lose that coloration in the hobby.

I'd like to be wrong on that.

Time will tell however. I've got ants in my pants to try to test out some of my hypotheses. 2020 should be the year when I get these experiments going.

This is all exciting and very interesting. Someday we should make threads that go more in depth with all of the info and your studies if possible. Would be cool to deep dive on some of these subjects. Goes to show how much there still is to learn about species of catfish. Such a vast and diverse family of fish that has already proven to have many species hiding within species. From what pics I've seen of the golden tigs and Jurs in thempast I've always felt it's a locale thing, diet as suggested, or possibly subspecies. However with that being said before Pseudoplatystoma was revised to all the new species I felt like they were just subspecies and was shocked to see it split to even more actual species. So one never knows

 

[Chicxulub]

This is all exciting and very interesting. Someday we should make threads that go more in depth with all of the info and your studies if possible. Would be cool to deep dive on some of these subjects. Goes to show how much there still is to learn about species of catfish. Such a vast and diverse family of fish that has already proven to have many species hiding within species. From what pics I've seen of the golden tigs and Jurs in thempast I've always felt it's a locale thing, diet as suggested, or possibly subspecies. However with that being said before Pseudoplatystoma was revised to all the new species I felt like they were just subspecies and was shocked to see it split to even more actual species. So one never knows

I mean to document my adventures into this once they truly start! For the time being, that's being pretty severely hampered as I'm on well water that's effectively liquid limestone and I just can't seem to keep the jurs alive. The thread will be quite detailed However, as I mean to test if a supplemented juruense will develop the nice yellows seen in wild specimens.

I too am inclined to believe that there may be more going on in Brachyplatystoma than meets the eye, akin to Pseudoplatystoma. I strongly suspect that there are species complexes of fish that are effectively visually identical from one another, but which are genetically distinct. In the stripey species like tigs and jurs, this could easily explain regional variation such as with the unique patter of jur that *apparently* only comes from Rio Nanay.

That being said however, I realize that I may be reversing course on the old "if it walks like a jur and talks like a jur, it's a damn jur not a flash zebra" stance.

Eh, not really.

I still feel that's the case until we have some sort of proof that FZ and jurs are in fact two different things that can potentially be sorted into unique species, similar to the six unnamed species or subspecies of African tigerfish known to exist but which aren't yet named.

Once some bit of evidence becomes available, we can speculate away, but until then, we have to accept the available evidence and accept that all jurs are jurs and a flash is in the eye of the beholder.