Rhyacoglanis aff. pulcher (nope, they're Pseudopimelodus) from the Rio Huallaga

[bekateen]

NOTE: This thread follows up on my effort to acquire

Rhyacoglanis aff_pulcher

, as shown HERE:

ALSO NOTE: I've had to update the title of this thread in early August after learning on August 5th that these fish are in fact NOT

Rhyacoglanis

but are really some kind of

Pseudopimelodus

!

Houston, we have a problem...

These

Rhyacoglanis

have been examined more closely by several scientists and specialists, and I believe that we confirmed they are not Rhyacoglanis, but rather are a type of

Pseudopimelodus

, similar to P. bufonius, but from wrong source, so I'll settle for

Pseudopimelodus aff_bufonius

.

Morning after they arrived. Settled into the tank well. Eating frozen blood worms today.

I'll be adding a false floor to the left 1/3 of the tank, similar to what I use in my Amblydoras tank (HERE), and I'll add a cluster of submerged (weighted to sink) spawning mops.

For source location, I'm told these are from somewhere along the Rio Huallaga. Hopefully I can get more info.

Cheers,
Eric

[bekateen]

When food is thrown in, they are NOT shy! Sadly, I missed the best scene, where one of these fish grabbed the entire frozen block of bloodworms and swam off with it. The other fish didn't know what to do, but eventually the block melted and the stealing fish lost its prize.

Direct link: Rhyacoglanis aff. pulcher feeding frenzy

[bekateen]

Working on the false floor and submerged spawning mops today. One mop done, four to go.

These submerged mops are based on the design I used while breeding Bunocephalus coracoideus (see this old thread, HERE).

Cheers, Eric

P.S., it's early (3:45pm) to start drinking, but I need one more cork, so... I must finish the bottle! Thankfully it was less than half full

Cheers! (Literally)

[bekateen]

The final product, with five mops.

Okay, not really "final"... Still need to perform a little bit of decor rearranging.

Cheers, Eric

[yellowcat]

Enjoyed the video, Eric! They seem to be a very active species if your video is any indication. Congratulations in finding them for sale and being the first on here to show them off. Their behaviors seem a bit different than Pseudopimelodus Bufonis for example that in my experience, their movements and feeding behavior were different in that their movements were more furtive, just moving briefly and quickly from spot to spot and otherwise very reclusive. Your fish are very attractive indeed and potentially candidates to be in a community tank as others may introduce, observe them and note interactions with other species. I admire your confidence with the attempt to induce spawning with a newly described genus and species a week or so out of the bag! Obviously your experience with Microglanis spawning success is leading to your advanced techniques to employ with these fish. Looking forward to the results of your endeavor!

[bekateen]

Their behaviors seem a bit different than

Pseudopimelodus bufonius

for example that in my experience, their movements and feeding behavior were different in that their movements were more furtive, just moving briefly and quickly from spot to spot and otherwise very reclusive.

So far, I think their behavior is very similar to that of my

Microglanis aff_iheringi

:

• They are super active after dark and first thing in the morning. When they come out at night, they whirl around everywhere, and there's always at least one fish spinning circles up the glass walls, over and over and over and over again.
• They hide a lot in day, but it's as if they want to be moving all the time, so they sit there, earnestly waiting for a reason to move even a little bit. When they come out during daytime, they don't swim into the open water or to the water surface. Instead, they skim along the floor, the walls and the decor, never spending much time in the open; they just dart from one hide to the next... and heaven forbid they try to enter a cave with another fish in it. They get into a big scrap until the invading fish is run off.
• They want to eat all day long, but if the lights are on, they don't want to come out of their hiding places to get the food. So they'll sit in a cave with their head barely sticking out, and if a food item drifts by, they'll sneak out no more than a half inch or so to grab the food, then immediately they back into their cave again. If the food is more than a half inch or so away from the cave, they come out slightly, but then let the food drift by uneaten... I guess it's just too risky to show yourself in daytime.

Your fish are very attractive indeed and potentially candidates to be in a community tank as others may introduce, observe them and note interactions with other species.

Yes, I think their small mouth size would make them safe in a community tank of similar sized (3"-6") fish. They voraciously go after frozen blood worms (as seen in video) and also go crazy for live blackworms (I was able to buy some a few days ago...it's the first time in almost two years!). I tried freeze dried krill, about 1/2 inch long, and they didn't touch them. I think they are too big to eat.

Right now the only tankmates I have with these Rhyacoglanis is a group of about 8-10 adult

Ancistrus sp`wabenmuster`

which I obtained from @jac in 2019 at the CSG meeting. Since I first got them, those fish have been in a 15 gallon tank. I'm sure they appreciate the extra elbow room in a 75 gallon tank now. Currently they hide among the large stones to the right side of the tank. They are not currently occupying any caves.

I admire your confidence with the attempt to induce spawning with a newly described genus and species a week or so out of the bag! Obviously your experience with Microglanis spawning success is leading to your advanced techniques to employ with these fish. Looking forward to the results of your endeavor!

Is it confidence? Or Tom-foolery? Thanks, but don't get me ahead of myself. Attempting to spawn and spawning are two different things. But I agree, hopefully my experiences with Microglanis and Amblydoras are good guides to follow.

If I do succeed in spawning them, I believe it will be the first recorded spawn in a home aquarium. But it wouldn't be the first spawn in captivity. @Peter Petersen has a group at Denmark's national aquarium, Den Blå Planet. Their group spawned a year or two ago. Even so, I'd consider it a personal achievement to succeed in a home aquarium.

Cheers, Eric

[bekateen]

Ugh. Okay I'm a little nervous today. Came home from work to find the tank, which is unheated except for the heat created by the powerhead and HOB, had reached 86F!

I opened the tank lids to help evaporative cooling. I'll add ice as soon as I have some.

These fish are supposed to be in the low- mid 70s. I hope this isn't too stressful.

This heatwave, and global warming in general, are going to be problematic.


Eric

[bekateen]

This morning I woke and the tank was at 76F. I started the day by floating a bottle of frozen water in the tank. That water had fully melted before I left for work. I left the lid open all day, and by the time I got home at 8pm, the tank was still 76F.

I did bring a chiller home tonight also, but I have to figure out how to connect it before I can use it.

But that will have to wait, because tomorrow I'll be busy retrieving other new fry... of the human kind! My first biological grandfry is coming out of his cave tomorrow morning. Needless to say, I'm excited.

... Can I get BLOG points for that?

Cheers,
Eric

[Shane]

Congrats Eric!
-Shane

[bekateen]

...tomorrow I'll be busy retrieving other new fry... of the human kind! My first biological grandfry is coming out of his cave tomorrow morning. Needless to say, I'm excited.

... Can I get BLOG points for that?

Cheers,
Eric

The deed is done. One fry entered the world today. Already sexable too! I wish catfish were that easy!

[bekateen]

I got the chiller setup today. Youtube video explaining the setup will be ready soon.

Before adding the chiller, and with outside temperatures down in the 90s (F) lately, I've been able to maintain the tank at around 76F by leaving the two glass lids open, causing evaporative cooling. But obviously, this means I've got to monitor tank volume more closely, so that the HOB and powerhead don't fail.

Now with the chiller, I'm closing the lid. I've repurposed the powerhead to drive the chiller's inflow. I bought a 28" high table stand so that the pump didn't have to fight gravity along the return line. I've set the chiller's thermostat to 74F but I expect that won't drop the tank to 74F, considering the thermal inputs from the HOB, the powerhead and the canister filter, and considering that I've now closed the lids. So over the next few days I'll make small adjustments to the chiller setting until I obtain a daytime tank temperature of 73-75F. That should be good for both the

Rhyacoglanis aff_pulcher

the

Ancistrus sp`wabenmuster`

.

Cheers, Eric

[bekateen]

Here's the setup:

Direct link to video: New chiller for Rhyacoglanis tank

Feedback appreciated.

Cheers, Eric

[bekateen]

Houston, we have a problem...

These

Rhyacoglanis

have been examined more closely by several scientists and specialists, and I believe that we confirmed they are not Rhyacoglanis, but rather are a type of

Pseudopimelodus

, similar to P. bufonius, but from wrong source, so I'll settle for

Pseudopimelodus aff_bufonius

.

The mystery is that according to the importer (whom I trust), the exporter swears these are from the highlands of Peru, along the upper Huallaga. That seems rather limiting to Rhyacoglanis. Checking GBIF.org and Specieslink.net, I find only Rhyacoglanis pulcher (R. aff. pulcher, technically) in this area; no Pseudopimelodus appear in these collections. But Pseudopimelodus are known from lower down the river along the Marañon. However, these fish have a very short postcleithral process and their eye shape/position are small and wide-set. These traits are indicative of Pseudopimelodus.

Six of them in a 4 foot tank works right now while they're 3" - 4" TL, but certainly won't work when they're all a foot long or more. Ughh. I enjoy these fish. What are the chances these are an undescribed Pseudopimelodus from the Peruvian highlands that, because of its habitat, doesn't exceed 15cm SL?

Cheers,
Eric

[yellowcat]

At one point prior to 2017 these species were all considered to be pseudopimelodus until the revision split the genus into pseudopimelodus and rhyacoglanis. If photos in the cat-eLog are any indication your fish so closely resembles image #1 under R. aff. pulcher although probably not scientifically verified, to my eye. If not a verified Rhyacoglanis species it certainly could be another pseudopimelodus species but in overall morphology doesn't appear to be just what's commonly seen as P. Bufonis with a generally more elongate shape, although that species seems to vary in appearance from disparate collection points. As new species are discovered and/or revised in recent years it's entirely possible that more pseudopimelodids exist than currently described. In the case of Batrochoglanis, I had kept Peruvian specimens decades ago (and currently) when no data existed showing the genus was endemic to Peru which you among others have since verified on site. With your recent acquisitions and no direct way to verify the true I.D. of course the most likely clue will be shown over time if they continue to grow much larger than they're 'supposed' to. That said, there has been data showing maximum sizes attained by many species that have been initially greatly underestimated by many sources, only revised by examples later on, showing larger sizes attained in aquariums. Other than dispatching a team of scientists to investigate species specific data to be found in the Peruvian Rio Huallaga, it's up to you for now...

[bekateen]

@yellowcat, you are correct; there is so much unknown about these. Regardless of how these develop, I think my fortune today sums up what I can expect:

Cheers,
Eric

P.s., this fortune was so much better than the one I usually get: a hand- written note in my cookie, stating "Help. I'm being held captive in a fortune cookie factory."

[bekateen]

Dang. See this post. Sheesh!
https://www.planetcatfish.com/forum/vie ... 38#p338538

[bekateen]

Update on these fish: Since August, work and a little travel have been keeping me busy and I never got to tear this tank down until today. Sadly, there are no remaining Chaetostoma aff. microps.

On the flip side, these Pseudopimelodus are doing well. They've all grown significantly, arriving in August at 7.5 - 9 cm SL, and now they're all between 10.2 - 11.4 cm SL!

Take the good with the bad.

Cheers, Eric

[bekateen]

I took out the largest individual today for a measurement and it went so poorly!

On the bright side, this fish was 13.3cm SL. It grew 2cm in two months - Wow, they are growing fast!

But the fish jumped out of the container and rolled/flipped across the surface, then fell 4 feet to land on a hard tile floor behind the cabinet, in a narrow 3" gap between the wall and the cabinet.

The fish was located about 2 feet away from the end of the cabinet, so I had to use a broom stick to reach the fish and nudge the fish closer to me (without allowing the fish to wiggle beneath the floor of the cabinet - if the fish had moved under, it would have been impossible for me to recover that fish!) so that I could finally grab the fish and get it into some water.

When I was able to reach the fish, the fish's mucus coat had collected a thick layer of lint and dust from the floor. Although the fish was out of water for less than five minutes, the fish appeared surprisingly lethargic, even after I cleaned it, removed the lint and dust and got it back into water. I returned it to its tank and now I just pray it wasn't permanently harmed.

Ugh,
Eric

[characinkid]

Hi Eric,
Sorry to hear about your fish trying to make a break for it down the back of the table!

I've had fish do similar things where they end up on the floor for a minute or 2 covered in dust etc. Ive found that most of them make it, although it does take them a couple days to recover.
Good luck.

[bekateen]

Pics today of one

Pseudopimelodus aff_bufonius

in tank (the usual view I have of them) and of another individual, caught randomly. The latter is 13.6cm SL; this fish is "random" in that I did not attempt to catch the largest fish, although I think it might be the largest fish. If you compare this fish to all six photos above, I'm pretty sure this fish is the same as the first fish displayed above (the fish I'm holding in my hand) from the Nov 18th photos. If it is the biggest fish, it's grown less than a half cm in the last month... that would certainly represent a slowing of growth since the January measurements.

Here's that same fish in video:
https://youtu.be/kapYmvFkKj4 Cheers,
Eric

[bekateen]

A deep tank cleaning today allowed me to catch all six

Pseudopimelodus aff_bufonius

. The largest is now 16cm SL.

I recorded some video of all of them, both indoors and out in the sunlight, and I put the largest in a box for better view. But unfortunately due to sun glare I apparently couldn't see what I was recording, so these screen grabs from the video suck.

Cheers, Eric

[bekateen]

Here's one loose in the tank after I finished:

Also, compare what they looked like one year ago (when I got them) to what they look like today. Both photos are taken in the same bucket. Compare how much of the bucket floor space they occupy. Dang they've grown!

Cheers, Eric

[Jools]

Might not be what you wanted, but they are pretty.

Cheers,

Jools

[bekateen]

Might not be what you wanted, but they are pretty.

Cheers,

Jools

Indeed they are, but I'm still mad at them for eating a dozen Chaetostoma.

Cheers, Eric

[bekateen]

Biggest fish is still about 16cm SL. No growth since last measurement, 9 months ago. Granted it's been winter for a few months in an unheated tank, but I would have expected some growth. Maybe I measured poorly.

I recently discovered they really like raw salad shrimp... the tiny shrimp. I've been feeding them about 5 times per week for two weeks now. Maybe with warmer temps this will get them going.

Pseudopimelodus aff. bufonius update 2025-04-19


Cheers, Eric

[bekateen]

@yellowcat... besides low temperature and maybe not feeding eagerly until recently, do you have any thoughts on why they haven't grown in almost a year?

Thanks in advance,
Eric

[bekateen]

After the water change, I Instituted two updates to the tank layout which I planned after (a) talking to Ole Paulsen in Oslo at the Oslo Akvarieklubb 95th anniversary convention and (b) visiting the Den Blå Planet in Copenhagen (again, thanks Peter and Johnny).

1. Make the habitat 2-tiered with a shelf to elevate some hiding places.
2. Add a small low tank filled with sand to the middle of the tank, in case the fish spawn over a sandy bed.

Stay tuned for more updates.

Cheers,
Eric

[bekateen]

Here's their tank, updated after I visited Norway and Denmark.

Cheers, Eric

Pseudopimelodus aff. bufonius tank 2025-04-20

[Jools]

That is covering a lot of bases! It's a faff, but another approach would be to keep only females in the tank and then add a male from time to time.

Cheers,

Jools

[bekateen]

That is covering a lot of bases! It's a faff, but another approach would be to keep only females in the tank and then add a male from time to time.

Cheers,

Jools

Thanks Jools. Not a bad idea, but it would require another tank, something I can't add right now. Hopefully they'll continue to get along well.

Cheers,
Eric