Ward's Damsel (species: Pomacentrus wardi) in taxonomy (Lizard Island Field Guide)
Pomacentrus wardi
Ward's Damsel


©Andy Lewis: An adult Ward's Damsel of the dark colour phase

©Andy Lewis: An adult Ward's Damsel of the light colour phase

©Rick Stuart-Smith: A large juvenile Pomacentrus wardi, Lizard Island area.
Kingdom Animalia
Phylum Chordata
Class Actinopterygii
Order Perciformes
Family Pomacentridae
Genus Pomacentrus
Species Pomacentrus wardi

Colours

              

Distinguishing features

A small herbivorous damselfish with a dark brown body. There appear to be two colour morphs in this species - the typical dark form found throughout the midshelf reefs of the GBR, and a paler form which is more common on the inshore fringing reefs. Both can be seen at Lizard Island, but the pale form is quite rare. The small juveniles of the dark form have dark upperparts, a yellow belly, an ocellus on the rear of the dorsal fin, and a series of electric blue lines on the forehead. The pale form juveniles differ in that they lack the dark forehead, the yellow is tinged with orange, the blue lines are less prominant. In both colour morphs the juvenile characteristics are lost with age, and the adult fish greater than 1 year old appear a uniform drab brown.

Size

  • Up to 11 cm (Standard length)

Depth range

  • Depth range data is not yet available.

Synonyms

Distribution


©Atlas of Living Australia: Australian distribution

Distribution and habitat preferences

Reefs and reef flats with a mixture of hard coral cover and dead corals covered in turf algae.

Found in most locations around the Island.

Behaviour

Ward's Damsel is a dominant component of the herbivorous fish fauna at Lizard Island, feeding on turf algae from a small defended territory. They like to farm algae on hard substrata, so are most common near areas of coral rubble offering some shelter. The two colour morphs have not been scientifically documented, but preliminary genetic analysis indicates they are the same species. At inshore reefs like Magnetic Island (8-15km offshore), the pale form and the dark form are found in roughly equal numbers. At Orpheus Island (25km offshore) the dark form is approximately twice as common as the pale, and at Walker Reef on the midshelf (60km offshore) the pale form is seen only as a rare vagrant. The small juveniles feed on plankton initially, but then soon stake out a territory of their own and start to feed on benthic algae.

Web resources

References

  • Allan, B.J.M. (2015). The effects of climate change on predator-prey interactions in coral reef fish. PhD thesis, James Cook University. LIRS catalog number 1975.
  • Allan, B.J.M, P. Domenici, S.-A. Watson, P.L. Munday and M.I. McCormick (2017). Warming has a greater effect than elevated CO2 on predator– prey interactions in coral reef fish. Proceedings of the Royal Society B, tba. LIRS catalog number 2175.
  • Bay, L.K. (2005). The population genetic structure of coral reef fishes on the Great Barrier Reef, Ph.D. thesis, James Cook University. LIRS catalog number 967.
  • View all references