Young adults are violet with blue spots in their back and transparent caudal fins.

At those points in the lunar cycle, the gravitational pull of the sun and the moon are very high resulting in spring tides.

Total clutch cannibalism by parental males has been observed in yellowtail damselfish directly and by analysis of gut contents.

It is hypothesized that the decision to stop providing care could be to reallocate time and energy to attract more mates and thus increase lifetime reproductive success.

Another possible reason is to increase growth rate or survival of parental damselfish in poorer condition.

[8] There is interspecific overlap of feeding areas of M. chrysurus and two other damselfish species—Stegastes dorsopunicans and Stegastes planifrons.

In terms of defending the feeding grounds from intruders, studies have shown that M. chrysurus is less competent than Stegastes spp.