What is this?

[lazarusthefishboy10]

This is my Golden Wonder Killifish. He has some red marks on his body but look like parasites or infections. Does anyone know what exactly is on the fish?
Cheers!

 

[Colin_T]

Blood, the fish has been attacked or injured by something in the tank.

Do a big water change and gravel clean the substrate every day for a week.

Clean the filter if it hasn't been done in the last 2 weeks.

Maybe add some salt or monitor and see how it looks over the next few days.

If you want to add salt, add 1 or 2 heaped tablespoons per 20 litres of water. keep salt in tank for 2 weeks.