Black spots on stingray

[icemountain]

Got a blue dot ray in recently. It did not have the black dots when I first got it. I can see those black specs moving around on it. Does anyone know what it is and how I can treat it? Currently in a tank by itself with aragonite sand.

 

[Jay Hemdal]

Got a blue dot ray in recently. It did not have the black dots when I first got it. I can see those black specs moving around on it. Does anyone know what it is and how I can treat it? Currently in a tank by itself with aragonite sand.

When you say you can see the spots moving, do you mean physically moving, or just that new spots are showing up in different locations?

Rays can develop something known as "wandering spot disease" that is caused by a crustacean parasite (like Argulus). Rays can also show dark spots due to fluke infections, or leeches, but those don't more around.

Treatments for all of these issues are difficult because this species of ray is delicate to begin with, and then, the treatments needed must be very strong, and also cause severe stress.

I'm afraid to get to the root of the issue will require a microscope - taking a skin scrape (not getting stung in the process!) and then looking under the scope to see what the cause is.

Is the ray eating?
Is it showing the "fin curling" issue where its wings curl up?

Jay

 

[icemountain]

I see the spots sort of “hopping” or scurrying around on it. It was sitting in clean water for 3-4 days before I noticed this. I don’t see any curling. Not sure if the aragonite sand has anything to do with it but I’m guessing not.

It did eat a silverside a couple of days ago.

 

[Jay Hemdal]

It does sound like fish lice, a copepod parasite, often specific to certain types of fish.

The normal treatment is Dylox, but that is fatal to stingrays. Formalin dips might help. but the ray would just get reinfected when you return it to the tank.

Insect Growth Regulators take time (they only kill the parasite at the time that they molt) but they are generally safe to use with fish: Here is a link to dimilin on Amazon:
Amazon product

Here is an article I posted on crustacean parasites:

Arthropod Parasites of Aquarium Fish - Hemdal

Parasitic Crustaceans (Copepods, Isopods, and Sea Lice) Jay Hemdal c.2020 This is an excerpt from my upcoming fish disease book - a section on arthropod parasites of fish; isopods and copepods. ------------------ Cause This disease problem is...

www.reef2reef.com

Jay

 

[icemountain]

It does sound like fish lice, a copepod parasite, often specific to certain types of fish.

The normal treatment is Dylox, but that is fatal to stingrays. Formalin dips might help. but the ray would just get reinfected when you return it to the tank.

Insect Growth Regulators take time (they only kill the parasite at the time that they molt) but they are generally safe to use with fish: Here is a link to dimilin on Amazon:
Amazon product

Here is an article I posted on crustacean parasites:

Arthropod Parasites of Aquarium Fish - Hemdal

Parasitic Crustaceans (Copepods, Isopods, and Sea Lice) Jay Hemdal c.2020 This is an excerpt from my upcoming fish disease book - a section on arthropod parasites of fish; isopods and copepods. ------------------ Cause This disease problem is...

www.reef2reef.com

Jay

I can do formalin in the tank if that’s better? I removed the sand yesterday so it’s bare bottom now.

I read your formalin method to treat the aquarium with 166 ppm. What’s the dosage to achieve that? It’s on a 40b with a HOB filter and a piece of live rock. I have never used formalin before but I do have it in case.

 

[Jay Hemdal]

I can do formalin in the tank if that’s better? I removed the sand yesterday so it’s bare bottom now.

I read your formalin method to treat the aquarium with 166 ppm. What’s the dosage to achieve that? It’s on a 40b with a HOB filter and a piece of live rock. I have never used formalin before but I do have it in case.

I worry about hitting that species of ray with a high dose formalin treatment, I've not done that myself. Maybe try a 100 ppm, 30 minute formalin dip first, just to see if it dislodges anything. Remember, formalin scavenges oxygen, so all treatments must be done with really strong aeration.

If that works, the parasites will be in the dip, so can't get back on the fish. then, you could treat the display with dimilin to kill any remaining juvenile parasites.

Jay

 

[icemountain]

I worry about hitting that species of ray with a high dose formalin treatment, I've not done that myself. Maybe try a 100 ppm, 30 minute formalin dip first, just to see if it dislodges anything. Remember, formalin scavenges oxygen, so all treatments must be done with really strong aeration.

If that works, the parasites will be in the dip, so can't get back on the fish. then, you could treat the display with dimilin to kill any remaining juvenile parasites.

Jay

Can I run uv, carbon, or a skimmer while I dose daily formalin in the qt tank?

 

[Jay Hemdal]

Can I run uv, carbon, or a skimmer while I dose daily formalin in the qt tank?

Not sure what you mean by daily formalin? If you are just adding it, you cannot go higher than 25 ppm and that is not nearly strong enough to kill this parasite. If you are talking about the high dose tank treatment, you need to change all of the water after the short treatment, so UV, carbon or skimmers don’t come into play. Like I said though, I have serious doubts if this ray will survive a high dose formalin dip, and then remember, formalin is very toxic to humans.
Jay

 

[icemountain]

Not sure what you mean by daily formalin? If you are just adding it, you cannot go higher than 25 ppm and that is not nearly strong enough to kill this parasite. If you are talking about the high dose tank treatment, you need to change all of the water after the short treatment, so UV, carbon or skimmers don’t come into play. Like I said though, I have serious doubts if this ray will survive a high dose formalin dip, and then remember, formalin is very toxic to humans.
Jay

Sorry, I meant the daily dosing for in-tank treatment instead of the 30-60 minute bath. But I just did a 10-minute freshwater dip and then put it in antibiotics with nitro, kanamycin, and Metroplex. I will see after this if the number of those black specs decreased or is the same.

Would the 25 ppm dosage kill the parasite if the ray is above to tolerate it for 7-10 days?

 

[Jay Hemdal]

Sorry, I meant the daily dosing for in-tank treatment instead of the 30-60 minute bath. But I just did a 10-minute freshwater dip and then put it in antibiotics with nitro, kanamycin, and Metroplex. I will see after this if the number of those black specs decreased or is the same.

Would the 25 ppm dosage kill the parasite if the ray is above to tolerate it for 7-10 days?

No - 25 ppm formalin won't help.

Where did you get the ten minute FW dip idea? Five minutes is the standard time frame, and I've found that a number of copepods won't release with a five minute FW dip - did you see any fall off?

Jay

 

[icemountain]

No - 25 ppm formalin won't help.

Where did you get the ten minute FW dip idea? Five minutes is the standard time frame, and I've found that a number of copepods won't release with a five minute FW dip - did you see any fall off?

Jay

I usually do 5-10 minutes depending on tolerance. Looked like the ray was able to tolerate it for the 10 minutes

I just went and checked carefully and I did not see anything come off in the freshwater bucket.

 

[icemountain]

No - 25 ppm formalin won't help.

Where did you get the ten minute FW dip idea? Five minutes is the standard time frame, and I've found that a number of copepods won't release with a five minute FW dip - did you see any fall off?

Jay

No - 25 ppm formalin won't help.

Where did you get the ten minute FW dip idea? Five minutes is the standard time frame, and I've found that a number of copepods won't release with a five minute FW dip - did you see any fall off?

Jay

No more of those black dots. Between the fresh water and the 4 hour bath in metro, nitro, and kanaplex, I guess it knocked them off.

 

[Jay Hemdal]

No more of those black dots. Between the fresh water and the 4 hour bath in metro, nitro, and kanaplex, I guess it knocked them off.

Just watch for a return - since the treatments were via bath, there could still be reproductive stages in the tank itself.
Jay