Freshwater stingray advice needed      8/30/19
Hello!
<Holly>
I am writing on behalf of my employer. She is an avid stingray hobbyist, owning very many freshwater rays, half of which are black diamond. She is having problems breeding the diamonds though and asked me to reach out to anyone who might be more knowledgeable about ray breeding. I know it might be a long shot to ask for advice but I am a bit desperate.
<Mmm; have read quite a bit, written some re FW rays, Potamotrygonids>
The rays seem to be having pups fine, but the pups only last about two weeks before losing some color, curling and then expiring. She gets maybe one or two out of every 20 that actually makes it.
<Yes... need to know, have information re mainly water quality (and maintenance therein) and nutrition here. How do folks treat the source water and what is its make-up? What foods are being employed and are they supplemented?>
Any advice at all would really be appreciated, thank you for your time.
Sincerely,
Holly
<Data please. Bob Fenner>
Re: freshwater stingray advice needed      8/30/19
Thank you Bob for replying,
<Thank you for sharing Holly>
She has a large setup. It's a 2000 gallon system consisting of three large oval concrete tanks, 2.5 feet deep, connected to a small hatchery consisting of multiple 50 gal tanks.
<Ahh! Am wondering, concerned with the accumulation of metabolites here>
fresh water source is well water which flows in constantly.
<Ah, very good>
There are 5hp submersible pumps which feed into sand filters then degassing towers. There are aerators throughout and a bio ball filter before the pumps.
<Wow! Some electrical cost now!>
parameters are normally around or close to : Ammonia - 0.25
<Aye; this NEEDS to be zero, zip, nada. This value alone might account for the trouble here. I'd look into using contactor... resin, carbon... to eliminate all NH3/NH4OH>
nitrite - 0
nitrate - fluctuates between 5 and 20, rarely as high as 40
<This too needs to be addressed. I'd keep NO3 concentration below 10 ppm at all times>
and PH - between 8.2 and 8.4.
<And this is way too high for wild-collected Amazonian rays>
The temp ranges between 81 and 83 Fahrenheit.
The well water was just tested for heavy metals, all came back looking fine.
<Good>
My employer's friend keeps insisting it could be bubble sickness so she ordered a TGP meter. I tested all over and have seen it up to 95.4 % O2 and 103.7 % residual TGP in the concrete tanks. I can't seem to find much about what levels rays can tolerate but the more I look into it the more I don't think that is it. The rays don't look like they have any visible tissue damage.
<Gas/embolism is not a problem w/ these values. Supersaturation is... and with the use of the towers, likely most all excess gas is released>
I separate the baby rays from the adults into floating baskets when i find them. i have also tried moving them to their own hatchery tank as well but same results. I have tried feeding finely chopped earthworms, live Tubifex worms and finely chopped fish but they are reluctant to eat.
<Mmm; I would further experiment, and provide the young with softer, more acidic water. Do see, read on the Net, Fishbase.org re their natural waters. Quite different than what they're being exposed to here. There are simple/r, inexpensive means to modify water quality. The young will be better off kept in the 50 gallon systems either separate from the recirculated water or very slowly dripped/overflowed>
Thank you again,
Holly
<Welcome. Bob Fenner>
Re: freshwater stingray advice needed      8/30/19
thank you very much, you have been extremely helpful. I'll relay all of this to my employer and try setting up a separate tank for the pups.
<Ah, good. I've visited a few Potamotrygonid hatcheries... your issue here is not uncommon, and easily solved. Bob Fenner>

Skinny Stingray    4/21/18
My motoro stingray is a pretty active stingray but parameters in the tank are normal (no nitrates, nitrites, ph levels are normal)
<I would prefer the values rather than a statement! To recap, nitrite should be zero of course, and nitrate as low as practical, though zero nitrate is in practical terms very difficult to achieve. If you are honestly getting a zero reading for nitrate, I'd double-check you're using the test kit right, because a zero nitrate reading in a tank with a large,
predatory fish is so unlikely. While the precise pH value isn't critical, it should be stable and not too high, and ideally, hardness and pH would be towards the soft water end of their respective ranges; maybe 2-15 degrees dH, pH 6.5-7.5.>
and there is no chance of infection or parasites.
<How can be you be so sure? Even at the retailer there's some risk of exposure.>
There are constant water changes and filter changes with at least 25% changed. He is fed everyday or every other day with more food (this does not happen often, but there are issues that come up as they do in life, but not enough for there to be leftovers in the tank).
<Understood.>
He has been in our tank for over a year and a half and has been growing steadily, so we are pretty sure there is no stress, and as he has survived this long and continues to grow.
<I agree, this is promising.>
Our substrate is a soft gravel that My parents used years ago with another ray who lived a long life (obviously rinsed thoroughly with water).
<I am sure you're aware of the debate surrounding the use of substrates in ray aquaria. There are arguments in favour of soft sand substrates, and arguments in favour of no substrate at all. I wouldn't say it comes down to personal taste, but the latter approach is perhaps easier and safer.>
He is a very happy ray in all searching through gravel, finding Blackworms, swimming around all normal ray things. My problem is that he is too skinny.
He is fed a good diet of shrimp, Blackworms and live fish (who have been quarantined by fish store for at least a month usually more) but he will not gain weight.
<Live fish is already one major risk factor. Let's be clear, unless you're home-breeding thiaminase-free fish from parasite-free parents, then any live fish are dangerous. End of story. For a start, cyprinids (goldfish, minnows, and their relatives) contain thiaminase and simply should never be used as live food. No scientifically sound argument can be made in favour of using those types of fish, and store-bought "feeder" goldfish and minnows are simply parasite-bombs. If you've used those, then right there is one very probable reason for the ill-health of your Stingray. Thiaminase is an enzyme that breaks down thiamin (vitamin B1) and when used regularly the predatory fish can/will develop all sorts of vague, but potentially lethal, health issues. There's a BIG scientific literature out there on this subject, but let me direct you to Marco Lichtenberger's summary here at WWM, written specifically for aquarists:
http://www.wetwebmedia.com/ca/volume_6/volume_6_1/thiaminase.htm
Next up, the feeder fishes bought at pet stores will almost certainly have parasites of some sort in them, and quarantining them only means those parasites aren't killing the host fish. Get those feeders inside your predatory fish and things become more complicated. A goldfish might, for example, have a degree of resistance to a certain parasite because they evolved together over thousands if not millions of years, but South American Stingrays may never encountered parasites common in Eurasia, and would have no resistance at all to that parasite. Do you see the problem here? It's not a definite explanation, but the use of feeders is just such a wildly risky chance to take, that it is very difficult to rule them out. Given Stingrays aren't obligate fish-eaters in the wild, there's no real reason to feed them live fish anyway, and most if not all experienced Stingray keepers and breeders avoid them. Instead focus on invertebrates, particularly worms, as well as more mixed, vegetable-rich food items that offer vitamins and fibre. Gut-loaded earthworms and river shrimps are a good way to get vegetables into your Stingray! Alongside these, a good
quality Stingray pellets will help round out their diet, and arguably could make up their entire diet if you're on a budget.>
He also completely refuses to eat things like smelt, nightcrawlers and even wild caught shrimp (as in once he smells it on your hand he will not come near you the rest of feeding time he hates them that much) and we have tried countless times to introduce him to other foods.
<The golden rule with fish remains this: they'll eat when they're happy and healthy. If they're not eating, it usually means there's a problem. It's very rarely the food itself that's wrong, but something else. Could be water quality or chemistry, could be the lighting (Stingrays hate bright light), could be the tankmates, if any (Stingrays are best kept alone). But as we've discussed, there could be a deeper problem if live feeders have been used, especially goldfish or minnows. Nobody keeping a fish as valuable and as delicate as a Stingray should be giving them live feeder fish.>
We have even hidden some in the foods he does enjoy and he spits out the food he doesn't like once he figures out it is there.
<Classic food refusal.>
He is too skinny but as I said he is still growing outwards so he is still healthy but I hate seeing him so skinny.
<I would be thinking along the lines of internal parasites, if he "eats but stays thin" but I'd also be worried about thiamin deficiency.>
Are there any fattening foods that I can safely feed a ray?
<See above; your Stingray doesn't need more calories, but he does need his appetite back. You need to review that aspect, and act accordingly.>
I've seen people suggest clams, muscles, and worms.
<Clams are good. Mussels can be used sparingly -- again, they contain thiamine. Earthworms are good and safe; bloodworms and especially Tubifex worms substantially more risky, and best avoided.>
We can try other fish but I'm not sure how he will react. Any tips or suggestions will be much appreciated!
<Hope this helps. Cheers, Neale.>

Lymphocystis and Potamotrygon (RMF?)<I totally concur w/ your stmt.s>     9/9/17
I recently found white cauliflower like white tufts on the side of one of my CA cichlids. Upon much research I've 99% concluded its Lympho. Now my whole 340g system is infected.
<Let's be clear about Lymphocystis -- although there is a pathogen involved, it is almost certainly triggered by the environment rather than being contagious. Some type of stress is usually involved. For example, maintaining Scats in freshwater rather than brackish water, or exposing bottom-dwelling fish to a substrate that isn't kept properly clean. In the wild, heavy metals and industrial pollution are believed to be the main reasons Lymphocystis becomes common in some lakes and seas.>
I was going to rearrange some fish, one of the being some Marble stingrays into the 340 and cichlids to another system. My question do I have to break the 340 down and clean it or will the virus disappear upon removal of the infected fish?
<There is no cure for Lymphocystis, and because it isn't contagious, it isn't something that needs to be eliminated. Treatment is really all about optimising living conditions (and probably diet, e.g., with a vitamin supplement and/or fresh green foods) and waiting for the fish to get better by itself. Lymphocystis tumours will take months, even years to subside, though vets will sometimes surgically remove tumours from big, expensive fish such as Koi. I think you'd be surprised how often Koi receive high-end medical care comparable to cats and dogs! For more mundane fish, time is the great healer when it comes to Lymphocystis. Do remember that Lymphocystis is unsightly but usually not life-threatening (unless the tumour obstructs something important like the mouth, gills or vent).>
Can Potamotrygon even catch the virus.
<Exposed to the wrong conditions for a long time, sure, it's possible. But the virus is probably latent in most aquaria, and not something we normally worry about being "catchy". Killing viruses in aquaria is virtually impossible anyway, though again, some treatments do exist for the high value Koi which are subject to viral infections of various types.>
What steps should I do to clean the system after removal of contagious fish and setup?
<Think about what inorganic stress factors (such as heavy metals, like copper) might be present in the system. Think about the cleanliness of the aquarium generally -- the quality of the water, the frequency of water changes, and the turnover rate of the filter. Low oxygen levels can easily stress big fish like Stingrays and South American cichlids. Diet is probably a factor too, especially when you're keeping cichlids -- most are omnivores in the wild, but aquarists frequently neglect the green content of their diet, and fresh greens are probably important sources of vitamins that help support their immune systems.>
Thanks, Don
<Cheers, Neale.>

Stingray; FW     7/23/17
Hi crew.
I have a newly acquired male motoro stingray and he seems to be behaving weird. I have him in a 220 with a pair of clown knives , an Oscar, a red devil, large albino iridescent "shark" catfish,
<Mmm; you know this fish gets HUGE I take it>
a red tail catfish,
<Ditto>
a Lima shovelnose, a Florida gar and a common Pleco. I got him 3 days ago and he is still not eating. I have offered tilapia and cod fillet, chopped market prawns and earthworms, ghost shrimp and some pellets. All items he was
eating previously. I have for the most part kept the lights off to help him adjust. I have a custom built filtration system and do 50 to 80 percent water changes every other day. Tank is bare bottom and the temperature is 79 degrees Fahrenheit.
<Mmm; well; you have a quite an "environmental mix" in fishes here... what are your water parameters in terms of the testing gear you have? Is your water very hard, alkaline?>
He keeps lifting his disc in front of his nose and placing it back down. The cichlids haven't touched him and the red tail catfish just pushed him out of the way and occasionally dog piles on top of him but this is the most extreme I have witnessed. I am aware of how big my fish get and have a suitable home under construction for them. Is this
normal for my ray?
<It is not unusual for Potamotrygonids to not eat for days after being moved; and they really don't like being prodded by other livestock. Do you have habitat where this fish can get out of the light, away from the other fishes?>
What does it mean? How can I get him to eat? Thanks
<I would be patient at this point... keep offering foods via a dowel (wood or plastic), right down in front of this fish daily. It should start taking food w/in a week. Bob Fenner>
re: Stingray     7/23/17
I do know my water has high PH around 8.2 but didn't expect it to be an issue as the water he was in before also had higher ph of around 8.2 , 8.3.
<Mmm; how long was this fish here? This is way too high period. The GH, KH?>
I don't have another set up at this time that would be adequate for him.
Ammonia is 0 and nitrates and nitrites are 0 as well.
<How are Nitrates rendered zip? Highly unusual w/ biological filtration, such large fishes>
I am just nervous as he is my first stingray and I spent years researching before my purchase but assumed since he was 8 inches across he would handle the catfish as he spent his days dog piling with leopoldi Ray's. Is the disc behavior a large concern at this point?
<Not a large concern, but the environment is BobF>
re: Stingray     7/23/17
As of right now the room I keep the tank in is lit by day light through one window and the tank has a small 5 inch LED light bar on it set to a midnight blue on one corner of the tank, where he chooses to be most of the time. I have 2 large pots forming somewhat of a barrier at opposite ends of the tank but nothing to where only the ray can access.
<I would be providing. B>
re: Stingray     7/23/17
He was there for the first year and a half of his life.
<Ah; good. This is a long period to become aquarium-tough>
Nitrates rendered 0 because I just replaced the biological media after a system malfunction during a power outage. It previously sat at 20 which is where I expect it to return to.
I am unsure of KH or GH at this time
<I'd be measuring; lowering if too high (by addition of less hard water).
Bob Fenner>
re: Stingray     7/23/17
What could you recommend that I construct or purchase that only the ray can access?
<Perhaps a raised up few inches PVC pipe array... made of tees or elbows and pipe sections>
An underwater sand box on one corner of the tank to wear he can bury himself ?
<Mmm; no; not necessary to have substrate>
Not too creative with what could be built or bought that only he could enter. I prefer bare bottom so I always know where the barbed venomous fish is and it's easier to clean but I want to make sure he is healthy and happy
<Understood. BobF>
re: Stingray     7/23/17
Have you heard of any other projects that could be built for him to hide?
<Wood and rock suspended overhangs>
I'm not sure if it'll work if the red tail decides to rest on top of it.
Just nervous about his well being. In addition to it being one of a few capstones of a monster fish keeper, and my first ray, they were essentially black listed in my country and now are not allowed to be imported or transferred over state lines. Just want to succeed. Am I likely to have success with this specie of ray with my set up and food I offer?
<I'd try blackworms, grass shrimp...>
Is there anything I could be missing in my set up to make him comfortable in terms of lighting or decor?
<... Please read here:
http://www.wetwebmedia.com/fwsubwebindex/fwstingrays.htm
You're not likely to have success given the mis-mix of species here... The Pleco, other cats... Bob Fenner>
I do have a strong current from the return out of 2 canister filter hoses and another from a sump return and a fourth from a wave maker.

Help us please... FW Ray dis./losses; no info.   3/14/17
Hi, I have eight black diamonds stingray and some question about their
diseases.
<Yeeikes>
Now l lost four of them on two weeks ,and i didn't know about its treatment.
The sign of them stress ,breathing very fast, something like flukes on tail and loose appetite in final they live in 2600 l .
Thanks for your response
<Need more information Amir. What re filtration, water quality tests?
Foods/feeding/nutrition? Are there other livestock present? What? The history of this set up please. Have you read on WWM Re? Start HERE: http://www.wetwebmedia.com/fwsubwebindex/fwraydisfaqs.htm
AND the linked files at top there. Bob Fenner>
re: Help us please... FW Rays... rdg., using WWM      3/15/17
Hi Bob
Thanks for your response.
<Welcome Amir>
I saw than link you mention before . I think it is better to give you more information that you guide me better.
<Yes!>
I use volcanic media in aquarium sump
<Mmm; I wouldn't. Please read here re:
http://www.wetwebmedia.com/fwsubwebindex/fwstingrays.htm
and here: http://www.wetwebmedia.com/fwsubwebindex/fwraysysfaqs.htm
and i have gold Arowana with them and they grazes Tilapia every day .
<Need more than this>
At least we change the water twice a week around 30% . By the way ,i think its relate to bacterial or maybe fungal diseases . Please give me a remedy to treatment .
<? Did you read where I referred you?>
Thanks in advance for your response
<Can't help you if you won't read. BobF>

Potamotrygon, bacterial involvement?     1/6/17 I am trying to find out if Potamotrygon species of stingrays can be infected by Columnaris. <Mmm; yes... I think so. Try the string, "Potamotrygon and Flavobacterium columnare" and you'll find a few "scholarly articles" linking the two> A friend recently had new pups appx 7 days ago and now these white spots/patches have randomly started to appear on them. I have treated Columnaris on Scats and cichlids for other bacterial and fungal issues topically with Methylene Blue with great success, but not sure if this would be OK with Stingrays. <Methylene Blue should be safe; though I don't know how effective> I also breed them but have never had this issue. Any help would be appreciated, I do have a couple pics he sent. <I'd do your best to produce and maintain "high quality" water; of low total bacteria count... I.e., massive water changes with soft, acidic new water frequently; over-filtered, uber-aerated... And optimized nutrition. Bob Fenner>