calcareous algae, near rocky crevices and overhangs. It has been recorded sheltering alongside juveniles of the native wrasse Coris julis. C. novemstriatus is nocturnal and emerges from its daytime shelters to feed in more open areas, and its nocturnal habits may have facilitated its successful invasion of the eastern Mediterranean, as few indigenous nocturnal competitors exist. Its main food is zooplankton, and in the Red Sea, it is frequently encountered at night along sandy shores at depths of 0.5-1.5 m. It is a social species and gathers in large groups, especially in its daytime shelters and even in the newly established Mediterranean populations, large schools have been encountered. Like other species of cardinalfish, C. novemstriatus shows pairing behaviour and courtship and the male broods the eggs in his mouth. References novemstriatus Taxa named by Eduard Rüppell Fish described in 1838