Care
The elegant Banggai Cardinalfish is known only from the Banggai Islands, an archipelago located off the far eastern coast of central Sulawesi (Celebes). These graceful, nocturnal fish are typically found dwelling amongst silty seagrass beds, sea anemones, mangrove roots, and coral ledges by day. Youngsters in particular are closely associated with the long-spined sea urchin Diadema setosum, where they will retreat amongst its spines for protection when threatened. At night, these fish feed on small benthic and planktonic crustaceans, in groups that sometimes number up to 200 specimens. In the home aquarium, it is important to provide a spacious reef setting with plenty of shady overhangs, nooks, and crannies. Just as essential is maintaining Banggai Cardinalfish in good sized groups (8+) due to their gregarious nature. Try to obtain fish that are the same size and add all simultaneously. Occasional minor scuffles may occur - usually consisting of chasing, nudging, and fin-flicking - but no real harm should ensue providing there is sufficient space and plenty of visual barriers amongst the decor. However, problems will arise if the group is too small and if the tank lacks space. In smaller set ups, it is best to house a known male-female pair only. Although tank bred specimens are considered relatively hardy, water quality should not be neglected; good filtration is a must and brisk water movement will be much appreciated. Tankmates can include other small, peaceful fish, even other cardinalfish species. Do avoid anything large and boisterous as cardinalfish are easily intimidated and may refuse to come out and feed. Also, be aware that although Banggai Cardinalfish are very placid, they are actually micropredators; therefore small shrimp and very tiny fish may be viewed as food items by larger specimens. Wild Banggai Cardinalfish are currently listed as "Endangered" on the IUCN redlist of threatened species. Thankfully, however, their readiness to reproduce in the aquarium has enabled breeding for the aquatics trade on a large scale. It is important that we, as conscientious aquarists, act responsibly and source captive bred Banggai Cardinalfish wherever possible, to help safeguard the very limited wild population.
Feeding
Offer a variety of meaty items such as Mysis shrimp, vitamin-enriched brineshrimp, finely chopped krill/cockle/clam meat etc. Feed small amounts 3 times per day, with at least one of the feeds after lights out.
Breeding
These fish breed readily in the home aquarium. When ready to spawn, courtship behaviour - usually initiated by the female - which consists of the pair swimming alongside each other nudging/trembling near the vent area, and the darkening of the males lower jaw, will take place for quite some time prior to the female releasing her eggs in close proximity to the male, near the bottom of the tank. The male fertilises the eggs (usually numbering up to 60) very quickly and immediately takes them up into his mouth for incubation. The eggs are quite large, at approximately 2.5mm in diameter and will make the males mouth appear a little distended. It is not uncommon for the female to aggressively protect the male when he is mouthbrooding. This is another reason why it is important to give these fish adequate space. The eggs/young will remain within the mouth of the male fish for some time; indeed, the eggs usually take around 20 days to hatch (temperature dependent) and after a further 10 days, when the young are more developed and grown to approx 6-7mm, they are released. During this month-long period, the male fish will not eat and attends to the brood by regularly turning them in his mouth and expelling any that have died. Once he releases the young, the male does not interact with them. There should be suitable shelter for the fry, amongst branching corals and long spined sea urchins.
