The narrowstripe cardinalfish (Pristiapogon exostigma) is a tropical reef dweller found between 3 and 20 m deep. This fish spends the day hiding under rock and reef ledges in sandy, muddy, or mixed sediments. This is a solitary nocturnal species, that feeds on fish and small benthic organisms. Juveniles live in coastal mangroves to protect themselves. They also form a close relationship with invertebrates, such as sea urchins, using them for protection.
The narrowstripe cardinalfish has an elongated slender body and large eyes on the pointed snout. The dorsal fin consists of two separate parts. The ribs are semitransparent, with a pinkish shade. The body is silver, looks yellowish during the day and blueish at night. The reason is not confirmed: it can be either colour change or trick of the light. A dark or lighter stripe runs along the whole body and ends with a black spot at the base of the tail. These distinctive features are barely visible when the fish is scared. All the fins are transparent.
|Australia||Narrowstripe cardinalfish, One-line cardinal, Oneline cardinalfish|