共栖

共栖	gòng qī	(old) (biology) to have a commensal relationship with (another organism)
共	gòng	common / general / to share / together / total / altogether / abbr. for 共产党, Communist party
栖	qī	to perch / to rest (of birds) / to dwell / to live / to stay
栖	xī	used in 栖栖