Threespot Humbug, Dascyllus trimaculatus (Ruppell, 1829)

Scientific name: Dascyllus trimaculatus
Alternative name/s:
Three-spot Dascyllus
  • Author(s)
    Mark McGrouther
  • Updated
    18/01/19
  • Read time
    2 minutes
Threespot Humbug Click to enlarge image
A Threespot Humbug at a depth of 3 m, near the swimming net, Clifton Gardens, Sydney Harbour, 7 April 2012. Image: Jayne Jenkins
© Jayne Jenkins

Fast Facts

  • Classification
    Genus
    Dascyllus
    Species
    trimaculatus
    Family
    Pomacentridae
    Order
    Perciformes
    Class
    Actinopterygii
    Subphylum
    Vertebrata
    Phylum
    Chordata
    Kingdom
    Animalia
  • Size Range
    The species grows to 13 cm in length.

Introduction

Threespot Humbug are blue-black with dark scale margins. Juveniles have a white spot on the forehead and one on the side of the body. It occurs in tropical marine waters of the Indo-West Pacific

Identification

Threespot Humbug are blue-black with dark scale margins. Juveniles have a white spot on the forehead and one on the side of the body. As an individual ages, the forehead spot disappears and the spot on the side of the body becomes indistinct or disappears.

Habitat

It inhabits lagoons and coral reefs. Juveniles are often associated with large sea anemones and are sometimes seen with Anemone fish. As they grow, Threespot Humbug lose the ability to live in anemones. Adults occur in small to large aggregations. The species occurs in depths from 1m to 55m.

Distribution

It occurs in tropical marine waters of the Indo-West Pacific, from the Red Sea, throughout South-east Asia and Micronesia, north to Japan, south to Australia and east to the Pitcairn Islands. In Australia the Threespot Humbug is known from the north-western coast of Western Australia and the northern Great Barrier Reef, Queensland, south to southern New South Wales and Lord Howe Island.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Click on the map for detailed information. Source: Atlas of Living Australia.

Distribution data sourced from the Atlas of Living Australia

Feeding and diet

The species feeds on algae, copepods and other planktonic crustaceans.

References

  1. Allen, G.R. 1975. Damselfishes of the South Seas. TFH Publications. Pp. 237. Allen, G.R. 1991. Damselfishes of the World. Mergus. Pp. 271.
  2. Allen, G.R. 1997. Marine Fishes of Tropical Australia and South-east Asia. Western Australian Museum. Pp. 220.
  3. Myers, R.F. 1999. Micronesian Reef Fishes. Coral Graphics. Pp. 330.
  4. Randall, J.E., Allen, G.R. & R.C. Steene. 1997. Fishes of the Great Barrier Reef and Coral Sea. Crawford House Press. Pp. 251.