Black Spots on Clown Loaches

Cheesyclop

Feeder Fish
MFK Member
Jul 10, 2022
24
22
8
Florida
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?
IMG_3993.jpegIMG_3983.jpegIMG_3982.jpeg
 

Fishman Dave

Potamotrygon
MFK Member
Nov 14, 2015
2,122
4,330
164
53
West Yorkshire
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.
 
  • Like
Reactions: Cheesyclop

RD.

Gold Tier VIP
MFK Member
May 9, 2007
13,470
13,459
3,360
65
Northwest Canada
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

Exodon
MFK Member
Jan 12, 2024
44
77
21
38
There is an old thread here with a few ideas


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.

Gold Tier VIP
MFK Member
May 9, 2007
13,470
13,459
3,360
65
Northwest Canada
Hierarchy issues typically result in greying out patterns, and look nothing like what that group is exhibiting.
 
zoomed.com
hikariusa.com
aqaimports.com
Store