The Great Fiji Butterflyfish Count

Chaetodon mertensii Cuvier, 1831

Max. size: 12.5 cm TL (male/unsexed; Ref. 4859)

Environment: reef-associated; non-migratory; marine; depth range 10 – 120 m

Climate: tropical; 30°N – 33°S

Importance: fisheries: minor commercial; aquarium: commercial; price category: not marketed/unknown

Resilience : High, minimum population doubling time less than 15 months(Preliminary K or Fecundity.)


Merten's Butterflyfish, FijiEnvironment: reef-associated; non-migratory; marine; depth range 10 – 120 m

Distribution: Gazetteer Pacific Ocean: Ryukyu Islands to the Philippines and extending to Lord Howe, Rapa and Tuamoto islands. Replaced by Chaetodon madagascariensis in the Indian Ocean, Chaetodon xanthurus in southeast Asia, and Chaetodon paucifasciatus in the Red Sea (Ref. 37816).

Morphology: Dorsal spines (total): 12 – 14; Dorsal soft rays (total): 21 – 23; Anal spines: 3; Anal soft rays: 16 – 17. Body color is white with 4-5 chevron-shaped blackish bands on the sides. The posterior portion of the trunk, the adjacent dorsal and anal fins, and the posterior portion of the caudal fin are yellow. A vertical black bar runs (uninterrupted) across the eye.

Vulnerability: Low vulnerability (10.00), based on Lmax and K (Ref. 59153)

Family: Chaetodontidae (Butterflyfishes)
Order: Perciformes (perch-likes)
Class: Actinopterygii (ray-finned fishes)
FishBase name: Atoll butterflyfish

Biology: Inhabit deep lagoons and seaward reefs. Occur singly or in pairs. Feed on algae and small benthic invertebrates (Ref. 1602). Oviparous (Ref. 205). Form pairs during breeding (Ref. 205). May hybridize with C. xanthurus.

\Main Ref: Myers, R.F.. 1991. (Ref. 1602)