Purple tang
A striking purple tang endemic to the northwestern Indian Ocean.
The purple tang (Zebrasoma xanthurum), also known as the yellowtail tang, is a species of marine ray-finned fish in the family Acanthuridae, which includes surgeonfishes, unicornfishes, and tangs. It is endemic to the north western Indian Ocean, found in the Red Sea, Gulf of Aden, around the Arabian Peninsula into the Persian Gulf, and near Socotra. The species is notable for its striking dark blue to purple body contrasting with a bright yellow caudal fin, and it is a minor item in the aquarium trade.
Quick Facts
- Taxon
- Zebrasoma xanthurum
Facts from the source article.
Lore & Background
The purple tang has a deep, laterally compressed body with a protruding snout and high dorsal and anal fins. Adults are dark blue to purple with a bright yellow caudal fin, while the head and anterior body bear black spots that extend onto adjacent fins; irregular black horizontal lines mark the rest of the body and fins except the caudal fin. Juveniles and subadults have dark brown longitudinal lines on their bodies. The maximum recorded total length is 36.7 cm, though 10 cm is more typical. This species is endemic to the north western Indian Ocean, occurring in the Red Sea, Gulf of Aden, around the Arabian Peninsula into the Persian Gulf, and near Socotra. A record from Sardinia is thought to be an aquarium release, and a record from the Maldives is considered a misidentification; the type locality of Sri Lanka is thought to be erroneous. It inhabits coral-rich or rocky areas at depths down to 20 m. Zebrasoma xanthurum is a herbivorous grazer of filamentous algae, feeding during the day in single individuals or pairs. At sunset, it stops feeding and moves into shelter among corals or in crevices for the night. Juveniles are cryptic and hide among corals. The species is a minor item in the aquarium trade.
Reader's Guide
The purple tang is a herbivorous grazer that feeds on filamentous algae, playing a role in controlling algal growth on coral reefs. It is found in groups over coral-rich or rocky areas at depths down to 20 meters. The species follows a daily pattern: individuals or pairs feed during the day, then at sunset they cease feeding and retreat into shelters among corals or crevices for the night. Juveniles are cryptic and hide among corals, likely to avoid predation. In the aquarium trade, it is a minor item. The IUCN assesses its global conservation status as Least Concern, but in the Persian Gulf, where suitable habitat is limited and subject to destruction by coastal development, it is assessed as Vulnerable.
Did You Know?
- The specific name xanthurum means 'yellow tail', referring to its yellow caudal fin.
- The type locality given as Sri Lanka is thought to be erroneous, as the species has not been reliably recorded there since its 1852 description.
- The purple tang is part of a species pair with the longnose tang (Zebrasoma rostratum).
- A record from Sardinia in 2015 is thought to be an aquarium release.
Frequently Asked Questions
What is the Purple Tang?
The Purple Tang (Zebrasoma xanthurum) is a small surgeonfish in the Acanthuridae family, instantly recognizable by its deep purple-to-dark-blue body paired with a vivid yellow tail. Hobbyists sometimes call it the yellowtail tang because of that contrasting caudal fin.
Where is the Purple Tang found in the wild?
This species is restricted to the northwestern Indian Ocean, ranging from the Red Sea and Gulf of Aden through waters around the Arabian Peninsula and into the Persian Gulf, with a small population near Socotra. It favors coral-rich or rocky reef sites at depths reaching about 20 meters.
How big does a Purple Tang grow?
Most specimens you'll encounter in the hobby hover around 10 cm (roughly 4 inches) in total length, though the species can reach up to about 36.7 cm (14.4 inches) under ideal conditions. That makes it a relatively compact tang compared to larger Acanthurus species.
What does a Purple Tang eat in a reef tank?
In the wild it is a dedicated herbivore that grazes on filamentous algae, so in captivity it thrives on a diet heavy in algae-based foods, nori, and vegetable matter. Providing plenty of live or cultured algae on the rockwork helps keep its coloration and digestion on track.
Why is the Purple Tang uncommon in the aquarium trade?
Because its range is limited to a narrow stretch of the northwestern Indian Ocean, supply to the hobby is small and it only shows up as a minor import item. That scarcity, combined with the fact that it is a sensitive grazer needing stable parameters and algae to feed on, means most hobbyists see it far less often than more widespread tangs.
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