Apogon cyanosoma

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See Talk:Apogon cyanosoma for individual experiences with this species, Apogon cyanosoma. Feel free to add your own personal experiences.

Common Name
Yellow-Lined Cardinal
Binomial Name
Apogon cyanosoma
Apogon cyanosoma 01.jpg
Scientific Classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Apogonidae
Genus: Apogon
Species: cyanosoma

Common Names

  • Yellow-Lined Cardinal
  • Orange-Lined Cardinal
  • Yellow-Striped Cardinal



Apogon cyanosoma is a relatively small fish, with alternating yellow or orange stripes on a silver base. The genus is renowned for their relatively large eyes, with the orange and silver lines continuing through. The orange stripes can be a strong orange, and can be used as an indication of an individuals health. Strong colour is generally recognized as a strong, healthy fish. Colours can be less intense, generally regarded as a response to stress, or related to a fishes age.

Similar Species

A. rubrimacula is identical but for a red spot at the midbase of the caudal fin. Similar to A. nitidus which has stripe through tail [1].

Maximum Size

8cm [1].

Associated Organisms

Associated with spines of sea urchins, this species co-habits with others of the same genus, and can also be found among the tentacles of anemones [1] in and near intertidal seagrass areas.


The Orange Lined Cardinal is a nocturnal, schooling fish. During the day, the species remains protected within the spines of sea urchins and near anemones, and ventures out at night to feed on zooplankton or small benthic invertebrates [1]. This genus is not noted for their swimming ability, and can show bursts of speed when threatened. Otherwise, they tend to "hover" in areas of low flow.

Captive Care

Tank Size

A relatively inactive fish, for which a <60L tank may be acceptable. Due to their scholling nature, a group of 5 or more are recommended for tanks >100L.

Water Flow

Their preference for flow can vary, with some hobbyists suggesting their behavior is not obviously correlated with water flow. The fish can hover in relatively forceful currents, but some prefer near stagnant flow. A tank with strong flow, such as those designed to house SPS, can still be suitable for this species.


Lighting is not a pre-requisite for this species, and seem undaunted by brighter light. Once aquarium lights are switched off in the evening, these cardinals will forego their daytime hovering to roam freely and occupy all parts of the water column.


Feeds exclusively from the water column - does not forage amongst substrate and rock for food. Food must remain suspended in the water column for some length of time. They have a large appetite but a small stomach, and will quickly fill to satiation. The mouths are large and they will eat a variety of prepared dried and frozen foods. Depending on brand, pellet food is less readily accepted than flake, which you could reasonably expect these fish to take to within hours of the fish being introduced to the aquarium. Frequent feedings are greeted with gusto, but probably not required given a relatively slow metabolism compared to damselfish. Feed little but often.

Growth Rate

The Orange Lined Cardinalfish is a relatively fast growing fish, if fed numerous times per day.


Isopods will attach to these fish. Considered a hardy fish against most common marine diseases. A strong and healthy fish will likely prevent infections.


An inactive fish that hovers mid-water keeping a sharp eye out for food. A schooling fish in the wild, on first introduction to an aquarium they may form a tight aggregation. From that point on there might be fighting to establish a pecking order, with the possibility of a persisting aggregation. Aggression towards other fish is very rare, and will likely avoid contact with other types of fish. Low-lying ledges and other places to hide are important for cardinals' wellbeing, providing them with a sense of protection.




Cardinals are timid and due to their swimming habits, are considered likely to fall prey to stronger predators. Should be kept with other timid fish, or herbivorous active fish which will likely avoid them.


Compatible with all coral.


Compatible with non-piscivorous mollusks, crustaceans and echinoderms. Has a preference towards urchins, and will co-habit well with a Long Spine Urchin.


Classic mouth-brooding reproductive strategy. The female will produce eggs, and will take no further part in rearing the offspring. The male will hold these eggs in his mouth, until the fry have consumed their yolk-sack. The male will need to fast during the egg holding phase. If he is not sufficiently prepared (good body condition) for egg holding, or frightened during that period, he may "spit" eggs. The incubation of the eggs in the mouth until hatching[1], makes them an ideal candidate for captive propagation.

Local Ecology


Red Sea to Marshal Islands, north to southern Japan and south to the Great Barrier Reef [1].


Sheltered clear lagoons harboring seagrasses and seaward reefs, 1 to 49m. In small aggregations under ledges, in holes, or among sea urchin spines by day. [1]

Additional Information

Additional information that doesn't fit in the above areas.



  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 (Lieske Myers 1996): Lieske, E., Myers, R., Coral reef fishes : Caribbean, Indian Ocean, and Pacific Ocean : including the Red Sea, Princeton University Press: Princeton, 1996.