Color Changes
Pale colors or stripes fading — early stress.
Very dark stress coloration — advanced stress.
Patchy color loss — disease or healing.
Fin Position
Clamped fins pressed to body — universal distress sign.
Erect fins with full spread — healthy or displaying.
Swimming Patterns
Hiding more than usual — bullied or sick.
Gasping at surface — oxygen deprivation or gill issues.
Darting erratically — water quality issue or parasites.
Scraping on objects — parasites or pH burn.
Appetite
Sudden loss of appetite — test water immediately.
Picky eating over days — consider internal parasites.
Body Condition
Hollow belly or sunken sides — internal parasites or starvation.
Bloated belly — overfeeding or dropsy.
Protruding scales — dropsy (critical).