dark / black

Myxobolus cerebralis
Fish with spinal deformity and darkened tail due to infection with M. cerebralis.
Myxobolus cerebralis
Rainbow trout infected with M. cerebralis.
Myxobolus cerebralis
Rainbow trout infected with M. cerebralis, showing characteristic black tail.
Tumor-like lumps
Tumors on lips of adult spring Chinook salmon.
Bacteria
Bacterial lesion on side of trout.
Flavobacterium colum...
Gill necrosis due to Columnaris