Anyone know is up with this sucking loach?

[serbusfish]

My parents have had a golden sucking loach for around 7 years now and its always been a bit of a beast, darting around the tank at will, regardless of what fish is in its way. However recently it seems to spend most of its time sitting in a corner of the tank and it looks to have marks on its body:



Anyone know whats up with it + what might the marks be?

[><))>WBW<((><]

If the marks you are referring to are the dark patches, it looks like ammonia burn, but I could be wrong as I do not know much about fish diseases.
If it is ammonia burn stating doing more water changes of larger amounts.

[talldutchie]

That's a very possible cause. What little I can see of the tank doesn't suggest a well kept setup to me and ammonia burns often happen with inattentive or unskilled fishkeepers.

[serbusfish]

Well the tank has been up and running for years, although they are very lazy and only do water changes once a month (ive tried to make them do more). They have been doing this for years so I dont understand why it would suddently hurt the fish? And everything else in the tank is fine.

[><))>WBW<((><]

Have they recently added more fish, this could have increased the bioload enough that the monthly water changes isn't cutting it anymore.

[talldutchie]

Giving the filter a good clean can also cause it.

[madagascariensis]

Having a tank set up for years doesn't really mean anything. In fact, an improperly cared for old tank might just start to suffer from old tank syndrome whereby bad maintenance practices do not remove as much waste as is being produced in the tank, causing a slow accumulation until eventually it reaches a lethal point. Since your parents change too little water this is pretty likely. If you have a test kit, just simply testing their water should give lots of insight

[mommy1]

They have been doing this for years so I dont understand why it would suddently hurt the fish?

If they have been doing this for years, it isn't "suddenly" hurting the fish, but the effects of years of bad tank maintenance are now showing. Your golden sucking loach appears to be a golden algae eater and a quick google search says they live 8 - 10 years. 7 years of poor tank maintenance easily takes several years off a fishes lifespan.

[serbusfish]

Hmm well I only have nitrate + nitrite test kits, nitrite comes up at 0. I'll pick up an ammonia test kit and see what it comes out at.

[mommy1]

Since they don't do much in the way of water changes and maintenance the tank is probably cycled, I am interested in what the nitrates are though.