Genicanthus semifasciatus

(Kamohara, 1934)

Japanese Swallow Angelfish

Range: Indo-West Pacific Ocean: Southern Japan, and south to the northern Philippines.

Size: 8 inches (22 cm)

Natural Environment: Inhabits seaward rocky reefs at depths of 50 to 600 feet (15 – 180 m) and is an open water plankton feeder.

General Husbandry: This very hardy species is occasionally available in the trade and when so, makes for a colorful and peaceful addition to both fish-only and reef aquariums. The male is quite different in coloration than the female (sexual dimorphism), having a yellow head and frontal sides with its upper body basically a dark yellow with many dark vertical bands. The female upper body is a greyish brown with white below, and has yellow along the edge of the dorsal fin and black on the head and tail. Both have a tail that tapers into the body, resulting in what can be called a swallowtail appearance. In fact, those in this genus are sometimes called Swallowtail Angelfish.

Best maintained in moderately lit aquariums since they are usually collected in somewhat deep water. As to diet, they should be offered at a minimum several daily feedings so as to quickly acclimate it to its surroundings. Like many others in this genus, their captive diet should consist of a wide variety of meaty foods including fortified brine shrimp, mysis and angelfish food preparations, and continued to be offered several times daily after its acclimated to its surroundings. Some flake foods, especially those containing Spirulina should also be offered occasionally, as algae, especially Spirulina is a healthy addition to all that consume it.

Depending upon its tankmates, it can be quite shy when first entering the aquarium, and may hide in caves and crevices. But as time passes, will become more outgoing. Those in this genus, as those in the genus Apolemichthys and Chaetodontoplus, are almost always very good tankmates and considered one of the least aggressive in the family. Keep in mind males will fight among themselves, so the limit is one per aquarium, whereas multiple females can be maintained, and all can be maintained with other genus angelfish.

Taxonomy:

Order: Perciformes

Suborder: Percoidei

Family: Pomacanthidae

Genus: Genicanthus

FYI: Keeping more than one genus of angelfishes in the same aquarium is possible, yet depends upon several aspects. The following suggested circumstances are just that, possibilities that when heeded and adjusted to actual aquarium conditions ‘may’ make multiple angelfish collections feasible.

Aquarium size – the larger the better.

Other species from the same genus should not be in the same aquarium.

The smallest and most docile genus species should be the first introduced with the largest and most malicious the last to be added.

Do not place similar coloration species in the same aquarium.

Those already in the aquarium should be well fed before adding a newcomer.

Have sufficient hiding places/rocky caves.

Keep in mind all angels have cheekspines at the edge of their gill cover; therefore use caution when handling and also avoid using a net to capture it, as it may become stuck or tangled in the net and become damaged when removed.

Synonym – Holacanthus semifasciatus

Experience Level: Intermediate

Temperament: Peaceful

Diet: Planktivore

Acclimation Time: 30 minutes+

Aquarium Environment: Fish-only and reef aquariums

Reef Safe: Yes

Minimum Tank Size: 125 gallons

Temperature Range: 70 - 77°F (21 – 25°C)

Specific Gravity: 1.020 - 1.026

pH: 8.0 - 8.5