Check adult requirements
Record the baseline and check adult size and ability to swallow tankmates. Do not infer the aquarium's condition from a single sign. Confirm scientific identity, adult size, diet, social behaviour and swimming zone.
Then compare uneven growth and nocturnal activity with livestock needs and recent changes. Look for genuine overlap in water, flow, territory and feeding throughout the year.
Assess compatibility and welfare
Adjust one variable and assess refuges that reduce encounters without excusing unsafe mixing before continuing. Keep a reference so the result can be compared. Plan the complete group and monitor feeding, breathing, injury, shelter and space use.
If a tankmate fits the mouth, coexistence is a matter of time rather than luck.