Larger 'Rays

[andywg]

This is a quick question for anyone kowledgable about 'rays;

Are there any true freshwater species that would grow large enough to be housed with RTCs and TSNs. I know the giant cats have huge mouths, but I seem to recall that some rays can hit 3'+ accross the disk, would they be large enough to avoid becoming a pancake style snack?

Edit:

Just done a little more research and found Potamotrygon brachyura which can grow in excess of 2m diameter. Need to check on water conditions but I would assume this is big enough?

On another note, I had been wondering about Arowanas, I know the Silver can get failry huge, but they tend to be a bit too thin in body cross-section and will probably be a cigar snack for the cats. Unless anyone knows differently?

 

[Black_Ghost_Guy]

There would be no need for such a large ray, a fully gorwn P. leopoldi, P. henlei, or even P. motoro should be fine. I've never heard of a P. brachyhura anywhere near that large, where was that info found? The china rays, ceja rays, and several Dasyatis rays can grow in excess of 4'. Is there any type of ray in particular that you have in mind? Are planning on purchasing these fish? If so, what size tank would they be going into?


EDIT: Oh yes, and the aro should be fine. They are very common tankmates for RTCs and TSNs.

 

[CFC]

There was a video doing the rounds on the net of a large TSN swallowing a equally large leopoldi ray TAIL FIRST in a public aquarium exhibit, the rays wings just folded over as it went down into the cats mouth and within a few minutes was completely gone, a very disturbing video
A full grown Potamotrygon brachyura should be large enough to avoid this fate but i should imagine you will have a hard time finding one, not to mention how expensive it would probably be.

TSNs also seem to have a addiction to swallowing large arrowana's, i have lost count of the number of threads ive read on various predator forums of how 20" plus arowana's have disapeered over night leaving just very fat catfish in the tank. RTC's would also have no problems swallowing equally large fish, there is a picture sequence posted on another forum of a 36" RTC swallowing a 30" clown knife.

The best tank/pond mates for these large cats are fish like pacu and enormous plecs which the cats cant get their jaws around.

 

[Discomafia]

RTC's would also have no problems swallowing equally large fish, there is a picture sequence posted on another forum of a 36" RTC swallowing a 30" clown knife.

Wow! I'd never have thought that could have happen... A 36" fish eating a 30" fish!

 

[andywg]

I knew about pacu (except that would destroy any chances of plants in the tank/pond) and I have seen them with plecos, however the display tank at the LFS has a pleco that is conspicuous by its absence in the RTC/TSN tank

My fear is that once fully grown very few (if any) plecs get large enough to be larger than an RTC's mouth.

I suspected that arowanas wouldn't be large enough in body cross section to prevent becoming a spaghetti style snack.

I wonder if once fully grown they would leave smaller fish, like neons?

I can't think of any other fish that would be ok with the big cats. An Mbu puffer might work, but would probably tear up all the finnage. Are there any other fish that get a large enought body to be kept with these boys?

Black_Ghost_Guy: I am planning on purchasing these fish in the next couple of years or so. I have decided once I have the room to construct a large pond/tank (around 17' long X 12' wide X7' deep) to house some big cats. I haven't decided on a part sunk pond or a tank yet, depends on final costs. As a result I'm interested to know what fish can go in with it.

 

[Paul_MTS]

I reakon a MBU could work. We have a Mbu in with a salmon catfish at work, i reakon the salmon could swallow the puffer if he wanted to, he even tried a few times half heatedly but never did.

Swallon aquatics at colchester has a huge TSN with some plecs. The plec must be fully gornw though as there just huge. He's in with pacus, perono (sp) cats a pangassuis and a smaller red tail aswell.

All get along fine. I would say the TSn is about 3ft.

you could try and get your hands on some arapaima which are in the arowana family and grow to aorund 10ft i think. Maybe some large gars would be suitable aswell, maybe even a alligator gar.

 

[andywg]

I saw that tank at Swallows on Wednesday. I didn't think the TSN looked fully grown. I know that 3 foot probably isn't, but I thought he was more like 2.5 feet.

The reason I fear for plecs is that as mentioned before, Swallows in Rayleigh used to have one the same size as the full grown ones in Colchester but in with around a 2.5-3 foot RTC and around 3-3.5 foot TSN and when I used to look into the tank I always thought that the pleco would easily fit into the RTC's mouth with room to spare

To be honest, once fully grown I think the RTC is more likely to eat tank mates due to him having a larger mouth - though I believe that TSNs are more predatory.

Hmm, I've looked up on the Arapaima and Alligator Gars, I fear they may get too large, especially the Arapaima with reports of max size reaching from 13 to 18 feet! Edit but it appears that most stay around 7-8 feet...very do-able...

Now, once this is off the ground, all I need to do is start charging people for a once in a life-time experience. "Swimming with Catfish" anyone?

 

[Black_Ghost_Guy]

Yes, a pirarucu should be fine, they rarely get over 8 feet even in large public aquariums.
CFC, do you have a link to that video? I have seen a myriad of medum sized rays (leos, etc.) kept with large RTC or TSN many many times, and have yet to hear of a problem. I see no reason why a 2' leopoldi could not be kept with a 4' RTC without being eaten. Also, Andy, if you need any help as to where to get a large aquaculture quality pond, let me know, I know of a plce in which you can get a 13,000 gallon pond for less than $2,000. Last thing - there are two pleco species that I know of that would not be eaten by a fully grown TSN or RTC, Acanthicus hystrix and A. adonis, each reaching over 2 and a half feet in length.

 

[Paul_MTS]

Just a note at the moment trimar have both of those formentioned plecs not too bad prices either. might be wse to get them to start growing

 

[Black_Ghost_Guy]

I need to move over there. Hystrix are pretty hard to find in the US.

 

[CFC]

CFC, do you have a link to that video? I have seen a myriad of medum sized rays (leos, etc.) kept with large RTC or TSN many many times, and have yet to hear of a problem. I see no reason why a 2' leopoldi could not be kept with a 4' RTC without being eaten.

Unfortunately not, the video disapeered with the demise of the old Aquatic terrors forum, shame really.
Dont forget that a rays wings are easily folded and the actual solid body area is only around 1/3 of the entire body mass, now think of a 8" fish with a 4 foot RTC and you have lunch. The really big cats should never be kept with anything you would be upset to see missing in the morning, these guys really are the top of their food chain.

 

[Black_Ghost_Guy]

That is true, but I would imagine that they would be too intimidated to eat a fish that is half of their own size in diameter. Also, to get a ray to roll up in such a fashion, I don't even know how they'd do it. They might not be the best fish to keep together, but they should be alright together. I have seen them kept together time and time again with no problems. It is very unlikely that you will encounter a "ray-burrito" being eaten by your large RTC or TSN. Very unlikely.

 

[andywg]

It's very unlikely, but obviously that means it is slightly likely... And I don't really want to use £200 feeder fish for these boys... And the more I look at RTC mouths, the more I think that very little can stand up to it. Hell, if the RTC turned out a big captive one (say 4.5 to 5 feet) and the TSN stopped at 4 I would be a little worried. Those mouths are big. That's why again, even a 2.5 foot pleco may still be a bit of a problem, if it curls up it'll only be a little over a foot long and still probably small enough in cross section to fit in the RTC's mouth...But if they did work, it'd be quite cool.

That 13,000 gallon pond is a bit large for my use and I'm tempting more and more towards a tank at the moment, if I can get it almost as cheap as a pond then I'm laughing. Even if not, the pond I'll make will be essentially a brick tank that is slighlty sunk into the floor with acrylic viewing windows in the sides.

So, possible fish mates for the RTC and TSN could now include the Arapaima gigas and Potamotrygon brachyura if I can find either of them.

Any more?

 

[Black_Ghost_Guy]

A P. brachyhura could possibly be eaten, it's not much more likely to be safe with a large RTC than a leo is. Also, it is very unlikely that you will be able to find one, I have never in my life even seen one for sale. Anyway, you could keep a large South American lungfish (Lepidosiren paradoxa) or Australian lungfish (Neoceratodus forsteri) in there, or a small school of pacus.