Species group: Chromis
Other common names: Black and White Chromis
Scientific name: Chromis margaritifer
Bicolor Chromis owners invariably refer to their pets as “personable”, and indeed these alert, hardy fish do seem to exhibit individual personalities.
The Bicolor Chromis ranges throughout the Indo-Pacific Region, where it lives along coral reefs in sizable schools.
Appearance / health:
The 7.6 cm (3 in) body is uniquely-clad in black from head to mid-dorsal fin, whereupon it becomes pure white.
Bicolor Chromis prove quite hardy if provided pristine water conditions and kept in schools of 5 or more. They are fast and alert, but may be injured or consumed by large fishes and aggressive invertebrates.
Behavior / temperament:
Bicolor Chromis are always on the go, moving about in schools. They can be territorial around a favored rock but are otherwise easy to keep with similarly-sized fishes. They will, however, fight with other Chromis species and most Damselfishes.
The Bicolor Chromis requires a well-filtered 113 liter (30 gal) or larger aquarium that is provisioned with moderate currents and numerous rock/coral caves into which they will retire at night. Live sand and live rock, which will provide some of the micro-organisms they relish, should be utilized if possible. Groups establish hierarchies but get-along well.
The following water quality parameters should be maintained in order to assure long-term health: Temperature: 24-26.6 C (74-80 F); Specific Gravity (Salinity): 1.020-1.025; pH: 8.1-8.4.
The diet should be varied, and include finely-chopped clam, squid, and prawn, live and frozen rotifers, cyclops, Mysis and brine shrimp, and flakes/pellets formulated for omnivorous marine fishes.
In most Chromis species, males guard short-term breeding territories. The eggs are attached to coral or algae, and the planktonic feed upon zooplankton. Some success has been had in public aquariums, but rarely if ever in private collections.
Written by Frank Indiviglio