Naso

Naso is a genus of surgeonfish in the family Acanthuridae. They are commonly called “unicornfish” due to the single, sharp, bony spine located near the tail. Naso species are found in tropical and subtropical waters throughout the Indo-Pacific region. These fish are herbivorous and play a crucial role in maintaining coral reef ecosystems by grazing on algae.

Characteristics

Naso species are characterized by their elongated, compressed bodies, which are typically blue or grey with distinctive patterns. They have a prominent, bony projection on their forehead, which resembles a horn or a unicorn's horn. This projection is more pronounced in males. Like other surgeonfish, Naso possess a scalpel-like spine located on either side of the tail, which is used for defense. They typically have a small mouth with numerous teeth, which are adapted for scraping algae off surfaces.

Environments

Naso species inhabit coral reefs, seagrass beds, and rocky shores. They are typically found in shallow waters, but some species can tolerate deeper depths. Naso are often seen grazing on algae in large schools.

Common Names

Common names for Naso species include:

  • Unicornfish
  • Surgeonfish
  • Naso tang

Species

There are over 10 species of Naso, including:

  • Naso brevirostris (Short-snouted unicornfish)
  • Naso lituratus (Littered unicornfish)
  • Naso tonganus (Tongan unicornfish)
  • Naso vlamingii (Vlaming's unicornfish)

References

FishBase
WoRMS
Animal Diversity Web