Blue Tang (Juvenile/Subadult phase)
Scientific Name: Acanthurus coeruleus
Category: fish

Brief Description
A vibrant purple or blue marine fish belonging to the surgeonfish family, distinguished by its oval body and sharp spine at the base of its tail.
Characteristics
Deep oval-shaped body that is laterally compressed. This specimen shows a deep blue or purple coloration with fine horizontal stripes. It has a white or yellow spine at the base of the tail (the 'scalpel').
Habitat
Coral reefs and grassy areas in shallow tropical waters.
When to Find It
Year-round; most active during daylight hours (diurnal).
Conservation Status
Least Concern
Ecological Role
As an herbivore, it plays a vital role in reef health by grazing on algae, preventing it from overgrowing and suffocating coral colonies.
Easily Confused With
Regal Tang (Paracanthurus hepatus), which has a distinct black 'palette' pattern and yellow tail, whereas the Atlantic Blue Tang is solidly colored as an adult.
Observation Tips
Look for them grazing in small groups or schools over reef flats. Avoid touching them as their caudal spines are sharp and can cause painful cuts.
Interesting Facts
This species undergoes a dramatic color change; they start life as bright yellow juveniles before transitioning to the deep blue or purple seen in this image as they mature.