Apogon semiornatus is a translucent fish with one main stripe (usually red) and little to none smaller stripes. Sometimes there are no stripes at all. This fish lives in the Indo-West Pacific Ocean, in the Red Sea and the Gulf of Oman, east to Australia, north to Japan, south to Natal,and in the waters around South Africa. This fish naturally lives in rocky and rubble reefs, and is secretive under pieces of material or in the back of low caves. These fish can live alone, but can and sometimes live in small groups.