There are many species of anthias – these small, brightly colored fishes usually live in huge schools. Within these large groups, are smaller units called harems. Each harem is led by the largest, brightest male. His harem consists of smaller males, many females, and juveniles.
  • Size

    3.5 inches (9 cm)
  • Diet

  • Range

    Western Pacific Ocean
  • Habitat

    Coral reefs

Physical Characteristics

  • Can reach a maximum size of about 3.5 inches (9 cm).
  • Appears in a variety of colors including purples, reds and oranges. Male has different coloration from female; colors are more vivid for males than females.

Animal Fact

All Bartlett’s anthias begin life as female – some individuals then change sex and become male as adults.

Diet / Feeding

  • Diet consists of zooplankton.

Range / Habitat

  • Occurs in tropical marine environments in the Western Pacific Ocean from Palau through the Caroline, Marshall and Fanning Islands.
  • Found on coral reefs at depths from 13-98 feet (4-30 m).
  • Lives in large groups with few males and several dozen females and juveniles. Groups appear in areas of branching corals where the fish are able to find shelter.
  • Active during the day and spends most of its time swimming above the coral reef and feeding on plankton.

Reproduction & Growth

  • Forms huge schools that are actually made up of small coexisting social harems.
  • Each harem is usually led by the largest, most colorful male; several smaller, less dominant males; a group of females; and juvenile fish.
  • The dominant male constantly defends its place in the group’s hierarchy by challenging the lesser males as well as other males from neighboring harems.
  • At dusk, the dominant male from each harem participates in “courtship dances” that entail frenzied, zig-zag swimming patterns that attract the females from their group and lead to coinciding spawning in the aggregation.
  • Sequential hermaphrodites; individual can change gender from female to male. All begin life as females.

Conservation Status

  • “Not Evaluated” on the IUCN Red List.

Additional Information

  • Due to environmental or social factors, such as the male dying, some females can become males. Sex-change ensures there will always be a male and a female to reproduce. The replacement is capable of changing her sex to male in a period of 2 to 3 weeks. The change cannot be reversed.


  • Reef Fish Identification – Tropical Pacific.  Allen, G.; Steene, R.; Humann, P. and Deloach, N., pg. 138
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