Lemon tetras exhibit an interesting behaviour pattern in the aquarium, replicated by several other characin species, in which males will adopt 'landmarks' within the aquarium and use these as places from which to display as maturity approaches. Displays are principally performed between rival males, which position themselves in a slightly head-up posture, unpaired fins held erect to appear as large and as imposing as possible, and swim forwards with 'flicking' movements of the body. If two rival males approach closely, they will then begin to make passes at each other, which to the causal observer look like attacks: this is an entirely ritualised behaviour, best referred to as 'jousting', where the males make darting movements toward each other but pull away at the last moment. No damage is incurred by either contestant in these events, and evenly matched males that are at a similar level in the social hierarchy will continue such behaviour for 30 minutes or more at a time. This behaviour serves not only to establish the social rankings of the males, but also serves as an indicator of reproductive fitness to the watching females.