Care
Merten's Butterflyfish is known from seaward reefs and deep lagoons (to a depth of 120m/394ft) where it may be observed singly or in pairs, feeding on small benthic invertebrates and various algae. This is a relatively hardy species that usually acclimatizes very well to aquarium life if kept in peaceful surroundings. It is often kept successfully in reef aquaria, providing it is well fed and is housed only with some of the more noxious soft corals that will not be too palatable - however caution and careful observation are advised. This fish does best in mature aquaria containing plenty of live rock for the fish to browse on and forage amongst. As with all butterflyfishes, this species demands excellent water quality - thoroughly filtered and well-oxygenated, with areas of decent current. Tankmates should be peaceable, and it is best to keep only oneMerten's Butterflyfish per tank. Do not house with any other butterflyfish species particularly close relatives, as this species will show much aggression towards them. Chaetodonmertensii is replaced by the Pearlscale Butterflyfish (C. xanthurus) in south-east Asia, and the Redback Butterflyfish (C. paucifasciatus) in the Red Sea. These species are collectively known as the "xanthuruscomplex". In the wild, C. mertensiiand C. xanthurus are known to hybridize where their ranges overlap. Fish from the Indian Ocean that are sometimes referred to as "C. madagaskariensis", are actually C. mertensii.
Feeding
Omnivorous. Offer a varied diet including Mysis, vitamin-enriched brineshrimp, Angel & Butterfly mix,and finely chopped krill, prawns, clam etc., plus some green foods. Feed small amounts several times per day.
Breeding
This species has not been bred in captivity. In the wild, these fish form distinct pairs and scatter their eggs in open water.
