Zebra danio abrasion?

[pocket22]

My danio kinda has a red line on its stomach what is it? I can't get a pic they move so fast! 1 or 2 have it not sure. Is it stress or something? Mty 15 was cycled for week or so and they were the first inhabitants. It's been established for 2 months or so

 

[Mumma.of.two]

What are the parameters and stock list? Is it an open red wound or redness on the scales?

 

[pocket22]

All nitrates are zero same with ammonia temp is 78 steady. No and No to ur questions. It kinda looks open not 100 percent sure.

4 zebra danios
3 long fin zd
3 platys
1molly
2 guppies (soon to be moved)

 

[pocket22]

No, not open