Profile of the fish species swallowtail angelfish

Swallowtail angelfish (Genicanthus sp.), front view

This type of stands out because it often leaves coral alone, making them appropriate for reef tanks. You will need a large tank, at least 125 gallons, to keep this fish because it can grow to be 7 inches long and loves a lot of swimming room.

Breed Overview

Common Names: Black-spot angelfish, spotbreast angelfish, Japanese swallowtail angelfish, blackspot lyretail, and zebra angelfish

Scientific Name: Genicanthus melanospilos

Adult Size: 7 inches

Life Expectancy: 10 to 15 years


Origin Western Indo-Pacific, Australia
Social Peaceful
Tank Level All areas
Minimum Tank Size 125 gallon
Diet Omnivore
Breeding Egg scatterer
Care Moderate
pH 8.1 to 8.4
Hardness 8 to 12 dGH
Temperature 72 to 78 F

Origin and Distribution

The Pacific Ocean's islands of Fiji, Indonesia, and Vanuatu are home to this species of angelfish. This species lives in shallow to deep seas on cliff faces. Typically, a single male is observed with multiple females.

Colors and Markings

Because of the black mark that may be found on the male's breast, this fish is also known as a "blackspot angelfish." The female has a bright blue ventral side and a yellow dorsal side. The top and bottom of the caudal fin's marine-blue color are accented by a thick, blue-black border. The entire pale-colored body of the male is marked with a pattern of vertical red stripes. Males have forked tails that are yellow with blue borders.

Apart from its crescent-shaped caudal fin, this species has a few additional distinguishing features. They have tiny mouths lined with three or four rows of tiny, triangular-tipped teeth that resemble bristles. The fact that they take food out of the water column rather than scraping algae off the encrusting debris explains why their teeth are shorter than those of the other Pomacanthidae family members.


More consideration and work should go into choosing possible tank mates for swallowtail angelfish than choosing their food. Since they are generally calm, swallowtails won't attack most fish directly, however they could hunt after little peaceful like Anthias fish.

Avoid putting swallowtail angelfish in a tank with fish that appear to be more aggressive. They may be ruled by stronger aggressors. Triggerfish, huge angelfish, and the majority of surgeonfish are examples of such aggressive fish.

Males from the same species, males from the Genicanthus genus, and fish with similar colouring will engage in combat. This fish may be kept alone, as a mated couple, or in a bigger tank, you can keep a small group of females with one male. Usually, it doesn't pay attention to other fish species, even unrelated angelfish. Clownfish, blennies, gobies, chromis, butterflyfish, tiny lionfish, and eels are a few potential tank mates.

Habitat and Care

The swallowtail angelfish is regarded as being difficult to ship in the aquarium trade. However, a healthy species adapts to life in an aquarium very fast if you can find one. This fish needs an aquarium that is at least 125 gallons in size due to its size and propensity for wandering. This fish needs lots of hiding spots and living rock to graze on. An excellent reef-dwelling angelfish that won't nibble at rocky and soft corals is this kind (sessile invertebrates).

Give the aquarium regions with lots of water flow during the day. Pumps should be run on timers that can be shut off after eight to ten hours. Water with good oxygen content is ideal. Since this fish could try to leap out of open tanks, lids are required.


This angelfish, which is a natural planktivore, frequently eats filamentous algae and diatoms in tanks. It should be given a variety of meaty feeds, including finely chopped fresh shrimp, frozen silversides, frozen brine, and mysis shrimp, as well as marine algae-based foods like dried seaweed (nori), enhanced flake food, or pellets with spirulina that are appropriate in size for angelfish.

This fish will suck food from the surface of the water while also possibly swallowing air. The fish may swell up and appear to be struggling while swimming head down. This is not uncommon. But don't worry, it exhales bubbles from its mouth and anus to release the trapped air. It farts and burps, in other terms. Feeding it food that sinks will help keep it from consuming air at the surface.

Sexual Differences

Due to their variations in appearance, only a select few angelfishes may be reliably recognized as male or female. The colour or pattern of males differs significantly from that of females. The male of the species, commonly known as the zebra angelfish, is identified by thin, vertical black stripes that run along the body from the head to the base of the dorsal and anal fins.

This particular species of fish is a protogynous hermaphrodite, which means that it first functions as a female and then, when the chance presents itself—typically due to the absence of a dominant male—changes into a male. It is said that this sex transition might take up to 30 days for swallowtail angelfish.


Males use a variety of fin motions and movements to persuade females to mate. Swallowtail angelfish males place themselves immediately in front of females or roll onto their sides or backs while trembling or quivering their caudal fins. The mating ritual is continued if the male is successful in his early tries.

The male will vibrate or tremble enthusiastically when positioned next to the female. The female will then spread her whole fin set out as a symbol of support. The male and female turn onto their sides and release their eggs and sperm after a few seconds of the male nuzzling his head close to the female's back, the pair being barely a few inches apart.

More Pet Fish Breeds and Further Research

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