Black Spots on Clown Loaches

[Cheesyclop]

This started a couple of weeks ago when I noticed some little black spots developing on my about 4-5in clown loaches.
All the water parameters are within normal limits and all other fish in the tank are fine.
The loaches are active and eating.
I first noticed this right after I added a piece of driftwood into the aquarium but have since removed it but I didn’t like the way it looked. (Not sure if it’s related in anyway)
I’ve tried to up the water changes and up the temperature to see if this would change anything.
Does anyone know what this could possibly be?

 

[Fishman Dave]

What decor do they have to hide in/under?
Some of those look like abrasion marks which have/ are healing. I would guess, and it is a guess, that they are from trying to squeeze between the wood and an abrasive sand especially as they seem predominantly on the head and don’t look like HITH disease.

 

[RD.]

I would look into this. I’m no expert, but it’s a possibility, especially if it spreads to other fish.

Black spot disease is spread by birds, and carried by snails. In freshwater fish there is no real treatment, you have to simply wait it out & make sure that the cycle cannot repeat itself. (do not keep snails with infected fish)

The OP's fish is WC, so it is very possible for it to have this disease.

Dr. Edward J. Noga, MS, DVM, a highly respected professor of aquatic medicine and immunology, that has been published approx 150 times in related papers/journals. His lab at NC State University specializes in the study of infectious diseases of finfish and shellfish. Here's what he has to say on this topic:

"According to Noga, if the fish has "black spot disease" there is no OTC treatment for the metacercaria (which are not in themselves lethal). They will simply "come out" of the cysts.

If there are no snails or copepods around, that is the end of the line. However, while the metacercaria are there, they can cause an immune reaction, which can be hard on the fish. If/when the metacercaria come out, they leave behind a hole that can get infected with bacteria and/or bleed. That is a danger to the fish. Salt in the water helps healing and increases production of the slime coat. Frequent water changes dilute out any possible infectious bacteria and supports the immune system. The key for fish survival (if they do not bleed to death from the holes) is a good immune system.

Black Spot is due to the metacercarian stage of a parasite with a complex life cycle called a "digenean" trematode . The "black spot" is caused by the metacercaria encysted under the skin which irritates the melanocytes of the fish tissue, causing the dark spot.

As long as it is under the skin, it is impervious from outside."


Tetra Parasite Guard contains Acriflavine, which would help with any potential secondary infections from the holes produced, but IMO lots & lots of fresh water, with some plain old kosher salt would be just as effective in that regard, without exposing your fish to the other meds found in Tetra P.

 

[Morti]

There is an old thread here with a few ideas

Mysterious black spots on clown loach

I was looking at my two clown loaches thee about 7-8 cm in length and the only other diesieses they have had is ich but that was a couple month ago ,they are well fed too ,but anyways they are more like black sploches and there over lapping each other,some are dark and some are light but there...

www.monsterfishkeepers.com

From what you have mentioned the 4-5" part is important. Do you have any other clown loaches that aren't affected? I say that because when clowns have their hierachal sparring matches, these spots seem to happen. It might be as a result of something else, like stress making them more susceptible to water parameters etc but it does seem fighting plays a part from my own experiences with them. The important part about the size is that it's about the size that hierarchy really becomes important and sparring becomes regular.

 

[RD.]

Hierarchy issues typically result in greying out patterns, and look nothing like what that group is exhibiting.

 

[Morti]

Hierarchy issues typically result in greying out patterns, and look nothing like what that group is exhibiting.

I wasn't suggesting that the sparring was the issue, just that these spots seem to occur after the loaches reach a size where hierarchy becomes important. I think, going by my loaches, that sparring can be quite intense and that it leaves the fish more susceptible to other things.

 

[RD.]

No worries, but in 30+ yrs of keeping this species, I’ve never seen black spots like the OPs fish are displaying. All groups of this species at all sizes have disagreements and disputes at times, and grey out, but they don't get black marks like that. I currently have an adult clown that is probably 10 years of age, that has apparently just recently got pissed off at the rest of the group, and has been greyed out and chasing the others for a couple weeks now. No black marks on any of them. The largest female in this group is 8-9”, and gets fussy and greys out and bullies the others as well at times. No black marks, even though I can see her physically thrashing some of those that are smaller than her. Homie don’t play nice. Lol

 

[Morti]

Tbh I can't remember if my group of clowns had the spots, i'm reasonably certain they didn't bit can't be 100% certain. I have had my group for 30 years, so their adolescents was a fair few years ago and my memory isnt the best. It was the big females that went to war with each other and they had the usual grey fading out.

 

[RD.]

Trust me, they didn’t.

 

[RD.]

Post pics of your 30 year old group, love to see them.