Housing Pterobunocephalus sp. advice?

[Narelle]

Hi all.
I was looking through the current stock list at TedsFishroom and came across the "Pterobunocephalus sp. - dark color" and fell in love. But I'm a little unsure if I could house them comfortably, so I was looking for some advice.

I had e-mailed Ted asking about the ID, to get a better idea of the parameters for this particular species, but he was unable to give me any more specifics than the genus and that they were collected from somewhere in Peru. If anyone is able to ID a more specific species please let me know, but for now I've been going off of the Cat-E-Log information for

Pterobunocephalus dolichurus

(since the other species had no water parameter information).

My dilemma is that the temperature range for P. dolichurus hardly overlaps with the fish I was hoping to house it with. The initial thought was that they would make a great addition to my future Catfish-Only Tank (which I was planning out here awhile ago...it's still just a plan at the moment), but some of the species I was wanting to keep in that tank have a lower range. They pretty much only overlap at 77 degrees, which is a little narrow for my comfort.

I like to plan my tank stocking with a chart to make comparing parameters easier, so here's the one I made for that tank:

The four species at the top are fish that I am definitely planning to keep (if I were to be flexible with any, it's probably be the H. jerdoni, though with other "banjo cats" in the tank I would probably be more flexible with B. coracoideus as well.), and the three fish at the bottom are possible additions, with the "Subtotal" below them comparing their parameters to the four definite species. The information regarding the addition of three Pterobunocephalus sp. is in red.

My other alternative would be to house them in the sump of my 150g, but I have the same dilemma in that tank with the temperature range (also just at 77 degrees exactly), and was also planning to use the sump for other things.

So that leaves either setting up a species only tank for them (which I could do, I have spare tanks that will be vacant shortly, but I'm supposed to be downsizing and there'd be less space than a 55g...most likely they would have to go in a 20g high, which is less space than I'd like, unless I managed to get another tank in my house) or pass up on these beautiful little cats.

So what should I do?

[bekateen]

Hi Narelle,

You've done a lot of work to figure out the housing conditions for your fish. I wish more people did that before purchasing the "cool" fish or the "pretty" fish.

However, I need to give you a word of caution regarding your dilemma:

My dilemma is that the temperature range for P. dolichurus hardly overlaps with the fish I was hoping to house it with. The initial thought was that they would make a great addition to my future Catfish-Only Tank (which I was planning out here awhile ago...it's still just a plan at the moment), but some of the species I was wanting to keep in that tank have a lower range. They pretty much only overlap at 77 degrees, which is a little narrow for my comfort.

In this thread (http://www.planetcatfish.com/forum/view ... =7&t=32393), @Racoll and others explain that it's not a good idea to put together fish which really don't belong together due to environmental preferences, under the idea that they "overlap" at their extremes. In essence, they may all survive together at that middle temperature, but nobody will really be happy or thrive, more than likely.

Based on that logic, you'd probably be better off limiting your fish choices to fishes which really do overlap well in their water parameter preferences (temp, hardness, pH, etc).

So that leaves either setting up a species only tank for them (which I could do, I have spare tanks that will be vacant shortly, but I'm supposed to be downsizing and there'd be less space than a 55g...most likely they would have to go in a 20g high, which is less space than I'd like, unless I managed to get another tank in my house) or pass up on these beautiful little cats.

So what should I do?

IMHO, the 20Gal High would make a wonderful species only tank for them since they don't get very long. I keep my

Bunocephalus coracoideus

in a 36Gal bowfront, which is a high profile tank, and they spawn regularly in it. I don't know the spawning habits of Pterobunocephalus (other than females may carry eggs on their stomachs), but if they are anything like B. coracoideus, then a high tank is helpful - my banjos swim upward towards the water surface before releasing the eggs. Maybe Pterobunocephalus perform a similar dance before releasing eggs. Such a behavior is also observed in a group of South American frogs (genus Pipa): Somewhat like Pterobunocephalus, Pipa frogs carry their eggs attached to the mom's skin (the only differences being (1) the eggs are attached to the dorsal skin, not ventral, and (2) these eggs sink into the skin, which forms pockets almost like little wombs)... My point is that like the banjos, these frogs swim up the water column before releasing eggs. So this is one instance where a taller tank is desirable in order to permit the fish to perform their "natural" behavior patterns.


Good luck!

Cheers, Eric

[Narelle]

I completely agree about housing species on the fringes of their range...I was more so holding out hope that someone might come along with new information that would suggest this particular fish might have a wider range than what is in the Cat-E-Log for P. dolichurus.

I guess what I'd really like to ask is how the temperature ranges for these fish are determined? Looking at the Cat-E-Log, P. dolichurus is listed as being fairly widespread. Perhaps I'm misunderstanding how to read the distribution map, but the points on the map are only in Brazil, Venezuela, and Paraguay (I suppose they are probably meant to be pointing out rivers rather than countries?). I know that the major rivers in Peru, where the fish I'm looking at were collected, drain into the Amazon Basin, so they are in a connected system. I looked at the Cat-E-Log for the ranges of other fish found in those rivers and while there is quite a bit of variation, most of the fish have a wider range than P. dolichurus. In fact, for such a widespread fish, P. dolichurus has a pretty narrow temperature range (77 - 80.6, just 3.6 degrees of tolerance). I do understand that temperature varies throughout the river and that depending on what areas the fish likes to live in, the temperature ranges may be vastly different than other fish in the same system. But I can't help but wonder at 3.6 degrees of wiggle room for a widespread fish to survive in.
Which brings me back to wondering how that range is determined. Is it determined by collection sites, or data collected when the fish was described? Is it possible, given such a narrow range for such a widespread fish, that there is little information about their particular range and that perhaps the given temperatures only represent tests done during one season?

And really, how much of this information about P. dolichurus can even be applied to the fish I'm looking at without definitively IDing that they are the same species? Species in the same genus can have considerable variation in water parameters, I worry that I may be way off base. (Other species found in the same river systems, even other species in the same family in those river systems, have much lower given ranges than P. dolichurus. And P. dolichurus is one of only two species described in the genus, and the only one with a given range. So I am basing everything on information about one fish that may not at all apply.)

Not meaning to question how things are done here and stir things up, I'm just looking to understand a bit better and hopefully get a better idea of what information actually applies to the fish I'd like to house. And probably still holding out just a little bit too much hope that a perfect solution will fall in my lap. ^^;;

EDIT: Posted before I read the thread you linked. Reading it now. I'm not used to South American fish, or uncommonly kept fish with few sources of information. I had no idea the Amazon was quite so stable...that does make the 3.6 degrees a bit more believable.
---

My only issue with housing them in my 20g comes from my reason to downgrade - my living situation will be changing in the coming year. My 150g and a couple smaller tanks will stay here and be cared for by a less experienced hobbyist who doesn't want to be left with too much. I'll be going into a variable living situation and definitely moving again in another year, so the most I'll be taking with me is my 55g (planned to be the Catfish-Only tank described above). So I'd need permission from the person temporarily caring for my fish, until I end up somewhere more permanent, or from the person I'll be living with, who would have to help me move these tanks as we move around. (Moving in with the guy I plan to marry, so he's stuck with me and my tanks.) Though finding a landlord that will be fine with a 55g should be difficult enough, without tacking on additional tanks.

If I were to go with the 20g, how many do you think I could house? I'm wary of limiting their space too much, with such small footprints on tall tanks, but I feel like when I buy wild caught fish I'm a little personally obligated to give a shot at breeding. A larger group would obviously give me a better shot at mixed genders and more chances for successful breeding.

---

I want to make this fish work, as I doubt I'd come across it many more times and have the chance, but I wonder if this one should wait for the days that I have a permanent home and a fishroom of my own to fill with as many catfish species tanks as I'd like...

[bekateen]

Racoll, you didn't say anything here; since Jools is still developing the @mention function, this is the "work-around" I'll use to alert you to a thread. ... Cheers, Eric

Hi Narelle,

Actually, your concern about the "universal" accuracy of the thermal preference data for all species in this, or any, website is fair. The data are only as accurate as the original sources (such as the person who described the spp., people who collect them more recently, etc.). And since there aren't very many keepers of either of the Pterobunocephalus species, that shows that people don't have a lot of experience with them, contrary to what is the case for some of the Bunocephalus, etc. A good resource which can expand your perspective on the number of locations associated with a species is gbif.org: http://www.gbif.org/occurrence/search?taxon_key=2340530.

I'm tagging Racoll in this thread because he seems to be very good knowledgeable on the rivers and habitats; hopefully he will offer some insights on P. dolichurus. Also, about the I.D., I've been looking at these fish from Ted Judy for a while now, and so far, dolichurus is my guess. I think that because they seem less like depressus than its original description. But I'm missing descriptive documents for dolichurus to allow a positive ID; in other words, I believe they are NOT depressus, but I'm not sure they ARE dolichurus.

I can see your tank space dilemma. As to stocking, I have somewhere between 5-7 B. coracoideus in my 36Gal (I never see them all at once). Most of the time, they just hide in the sand until lights out. They show little or no signs of aggression, and they will often congregate together and lay on top of each other, leaving the rest of the tank unoccupied by banjos (it is a community tank, so there are other fish in there too). If your Pterobunocephalus are similar in temperament (and considering that both spp. of Pterobunocephalus are only 3.5" SL as adults), I would imagine that 5, maybe even 6, could fit in your 20Gal, if you aren't adding a lot of other fish to the tank. If you add some fish to the upper water layers, then maybe 4-5.

Hopefully others, who have kept this genus or who have collected in the wild in their area, can chime in with more informed opinions.

Cheers, Eric

[bekateen]

Dang, I forgot to put Racoll's name inside the quote tags. Let's try that again:

Racoll, you didn't say anything here; since Jools is still developing the @mention function, this is the "work-around" I'll use to alert you to a thread. ... Cheers, Eric

[racoll]

I guess what I'd really like to ask is how the temperature ranges for these fish are determined?

Actually, your concern about the "universal" accuracy of the thermal preference data for all species in this, or any, website is fair. The data are only as accurate as the original sources (such as the person who described the spp., people who collect them more recently, etc.). And since there aren't very many keepers of either of the Pterobunocephalus species, that shows that people don't have a lot of experience with them, contrary to what is the case for some of the Bunocephalus, etc. A good resource which can expand your perspective on the number of locations associated with a species is gbif.org: http://www.gbif.org/occurrence/search?taxon_key=2340530.

Thanks for the tag Eric.

On top of what you said, basically for a lot of species in the clog, and especially those we don't know a lot about, the numbers are mostly just an educated guess based on almost no actual data. Therefore making these kind of tables of temperatures and calculating a happy compromise is pretty meaningless if you ask me.

For these species we know very little about, GBIF should indeed be the first place to look. I should do a tutorial post on how to get this information, but looking at all 20 Pterobunocephalus records, it seems they're found in both small creeks and larger rivers, and so should tolerate a wider variation than suggested in the CLOG. Perhaps say 25C-30C.

Whether these banjos should be mixed with the Indian Hara catfishes, I am not sure. I kept Hara in an unheated tank at about 18C-20C, a temperature I would never subject a lowland Amazon species to. India certainly has a lot more seasonality than the lowland Amazon does, but most people keep these on the cooler side (see the COTM).

There is also the question of minerals. The Hyalobagrus are blackwater specialists from peat swamps. Would these mix well with the whitewater Hara?

[bekateen]

...basically for a lot of species in the clog, and especially those we don't know a lot about, the numbers are mostly just an educated guess based on almost no actual data. Therefore making these kind of tables of temperatures and calculating a happy compromise is pretty meaningless if you ask me.

No disrespect intended, but I would disagree with this conclusion. While it's true that some of the data will be no more than an educated guess, that is still better than an uneducated, blind foray into the unknown. I would always encourage people to do their "research" before buying any new species of fish, or before mixing fish together that they aren't familiar with. So even if there is potential for mistakes because of holes in our knowledge about certain species, I think that a table like Narelle's is better than it is worse...

Let's put it this way: The table is a good starting point, one which should catch glaring problems. But it may not have been constructed quite as well as it could have been (Aside: Narelle, don't get me wrong, I like the chart). Based on Racoll's comment about minerals, the column labeled "conditions" proved to be an undefined category. This is because it uses different criteria to categorize the various fish species, rather than a single set of mutually-exclusive options to describe this variable. The options currently in this column include things like, "little or no current," "hi DO", "good water quality," and "dH 20." This is a problem because some fish might want good water quality and hi DO; in other words, one option doesn't exclude the others. This can be addressed either (1) by changing the answer options for this column to some like "blackwater, white water, clear water" (these terms aren't perfectly "mutually-exclusive," but they typically are used in opposition to one another), or (2) by splitting this column into two or more columns, one for hardness or TDS, one for oxygenation level, one for flow rate, etc.

(IMHO) Narelle, given your housing situation, figure out what you are able to provide your fish, in terms of tank size, water quality, temp, pH, etc. Then make some hard choices about how many species you will actually be able to keep at once. Try to pick fish that will "like" your water and setup, not just fish that "may survive" in it.

The reality is, we as humans don't take kindly to being "limited" - if we want something, we want it, and we don't like being told no... That's human nature (there are other terms for it, but I'll stick with that one). But sometimes, an externally-imposed restraint is appropriate, so that in our own wishes to achieve some goal (no matter how noble or compelling), we don't inadvertently cause harm to the animals in our care. As an example, let me share a mistake I made, and one I accidentally avoided making: I bought myself some

Scleromystax barbatus

last year. They grew well, bred and thrived for a year. They like cooler temps, so I kept them in an unheated tank; the tank temp was typically 74-78F, no less than 70 in the winter. Then last month we had a couple of heat waves, temps in the 100's. All the tanks in my house rose to 82F as their minimum temp for a few weeks in a row (even though the air conditioning is set around 76-78F). None of my fish suffered EXCEPT these Scleromystax: they became stressed, then one-by-one they died. You can probably imagine how disappointed I am, and how responsible I feel. Until I have a different arrangement for my tanks, I've resolved not to buy cool water species anymore. That was my mistake, bringing these fish into my house. Fortunately, I also dodged a similar mistake at the same time: Last March, I tried to buy

Glyptothorax lampris

(http://www.planetcatfish.com/forum/view ... =9&t=41764). They were advertised for sale the day I visited the LFS (WetSpot Tropical Fish in Portland), but the clerks said that the fish weren't out of quarantine, so they weren't for sale. Now I am so thankful that I didn't get them last March, because they too probably would have died in the heat waves.

...

...

Sorry, I got a little preachy there. That was probably more therapeutic for me than helpful for you. Whatever you settle on, these are pretty cool fish. I'm confident you'll enjoy them.

Good luck, Eric

[racoll]

No disrespect intended, but I would disagree with this conclusion. While it's true that some of the data will be no more than an educated guess, that is still better than an uneducated, blind foray into the unknown. I would always encourage people to do their "research" before buying any new species of fish, or before mixing fish together that they aren't familiar with. So even if there is potential for mistakes because of holes in our knowledge about certain species, I think that a table like Narelle's is better than it is worse...

Absolutely. Don't get me wrong, it's a great idea to research and synthesise all the available information into a table that's easy to digest and compare.

My issue is only really with taking some of those values too literally.

[Narelle]

Thank you both for all your help. You've definitely broadened my understanding of determining fish's water preferences, and GBIF looks like a great resource that I had no idea even existed.

The suggestion of adding another tank on either end of my housing situation is not going over well, so it looks like these gorgeous little fish will have to wait for an eventual fish room in the future. Or, at least wait a little while longer - perhaps I'll find a way to convince one of the two. But either way, I definitely don't want to be keeping any fish in conditions that they won't thrive (not just survive) in if I can help it, so the Pterobunocephalus will definitely not be going into my Catfish-Only tank.

As for the other fish, I must have overlooked the difference in water type...I didn't realize Hara jerdoni was a whitewater fish. Now you've got me completely reassessing my stocking plan for that tank. Though, I should probably leave discussion of that for my original thread on the subject.

(Apologies for the delay in response and the short response, I'm running on little sleep. ^^;; I had to help acclimate 500 fish in the middle of the night earlier in the week, and have been working nonstop since, as we are shorthanded at the moment.)