Two-Color Chromis (Chromis dimidiata) Care Guide
Chromis dimidiata, the chocolatedip chromis, is a Red Sea damselfish with a striking dark front and pale rear, forming aggregations over reef tops.
Compiled by Aquairi from published sources · Published · Updated
Overview
Chromis dimidiata, the chocolatedip chromis, is a damselfish of the family Pomacentridae known for its two-tone pattern. FishBase restricts the species to the Red Sea and places it in the genus Pycnochromis (Pycnochromis dimidiatus).
Taxonomy
- Family: Pomacentridae
- Genus: Chromis
- Scientific name: Chromis dimidiata
- Current placement: Pycnochromis dimidiatus (FishBase)
Habitat
According to FishBase the species is restricted to the Red Sea in the western Indian Ocean. It inhabits lagoon and seaward reefs at depths of 1-36 m, with adults gathering in large aggregations over reef tops and the upper edges of slopes. Preferred temperatures range from about 24.8 to 29.1 °C.
Tank requirements
- Minimum tank volume: 200 L
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- Specific gravity: 1.024-1.026
- Carbonate hardness (dKH): 8-12
- School size: 6 or more individuals
- Adult size: up to about 9 cm
- Lifespan: 8-15 years
Diet
FishBase gives a trophic level of 2.7, indicating an omnivorous diet. In the aquarium small frozen and prepared marine foods offered two times daily are suitable.
Compatibility
A peaceful mid-water species. It mixes with clownfish, tangs, wrasses and gobies. Aggressive damselfish and predators such as lionfish should be avoided.
Reef compatibility
The two-color chromis is reef-safe. It feeds over reef tops and does not harm corals or invertebrates, suiting reef aquariums with moderate flow.
Breeding
Reproduction involves distinct pairing during breeding, with males guarding and aerating the eggs. Captive breeding is considered difficult.
Conservation status
IUCN Red List: Least Concern (assessed 2010).
Two-color Chromis Breeding Guide
Overview
Chromis dimidiata (recorded by FishBase as Pycnochromis dimidiatus) is, under that name, restricted to the Red Sea in the western Indian Ocean and reaches about 9 cm. It occurs over lagoon and seaward reefs, typically in aggregations over reef tops and upper slope edges. FishBase records it as oviparous with distinct pairing during breeding, demersal eggs adhering to the substrate, and male guarding and aeration. IUCN status is Least Concern.
Sexing
There is little durable external difference between the sexes outside the spawning period, so reproductive behaviour is the practical guide. The male establishes and maintains a substrate nest, while the female enters it to lay eggs. Maintaining the species in a group gives the best chance of a natural, compatible pair forming.
Conditioning
A group held in stable reef water and fed several small meals a day comes into condition. Frequent feeding of fine planktonic and meaty foods supports egg production and matches the planktivorous habit of an aggregating reef-top chromis described on FishBase.
Breeding Setup
As in other pomacentrids the male clears algae and invertebrates from a patch of hard substrate to make a nest, so the system should offer exposed flat rock in a defensible territory. A spacious reef tank lets the aggregation behave naturally while a male holds and prepares its nest site.
Spawning Behavior & Trigger
Damselfish court with ritualised displays of rapid movement, chasing and fin extension. The female lays a layer of sticky eggs on the cleared nest, and the male follows to fertilise them externally. FishBase notes distinct pairing during breeding for this species.
Egg & Fry Care
The demersal eggs adhere to the substrate and are guarded and aerated by the male. Across Pomacentridae incubation takes about two to seven days, and the hatched larvae of about 2 to 4 mm enter a pelagic stage lasting roughly a week to over a month, feeding on very small live plankton such as cultured copepods.
Common Challenges
The pelagic larval phase is the principal obstacle: the larvae are minute and need a continuous supply of dense live plankton that is impractical in a typical home tank. With no documented species-specific rearing protocol, captive spawning of Two-color Chromis usually ends at the planktonic larval stage.