Naso

The genus Naso was first described by the French naturalist Bernard Germain de Lacépède in 1801. He described two species in this genus, Naso hexacanthus and Naso unicornis, both of which are still recognized today.

Here are the 20 species currently recognized in the genus Naso, listed alphabetically:

1. Naso annulatus
2. Naso brachycentron
3. Naso brevirostris
4. Naso caesius
5. Naso caeruleacauda
6. Naso elegans
7. Naso fageni
8. Naso hexacanthus
9. Naso lituratus
10. Naso lopezi
11. Naso maculatus
12. Naso-mineur
13. Naso mcdadei
14. Naso multibarbatus
15. Neus reticulatus
16. Naso sororius
17. Naso thynnoïden
18. Naso-tongaan
19. Naso eenhoorn
20. Naso vlammenii

The genus Naso, commonly known as the Unicornfishes, is characterized by its elongated, compressed body and distinctive unicorn-like projection or horn on the forehead of adult individuals. This horn is formed by the elongation of the nasal bone and is absent or less pronounced in juveniles or females.

Diet

Unicornfishes, which belong to the genus Naso, are primarily herbivores, feeding on algae and other plant material. They use their sharp, beak-like mouths to scrape algae off rocks and other surfaces, and can also consume detritus and small invertebrates.

Some species of unicornfishes have been observed to switch to a more omnivorous diet when algae is scarce or unavailable. For example, they may feed on small crustaceans, mollusks, or even coral polyps. However, plant material still makes up the majority of their diet.

Habitat

Unicornfishes, which belong to the genus Naso, are found in tropical and subtropical waters of the Indian and Pacific Oceans. They are commonly found in coral reefs, rocky areas, and seagrass beds, typically at depths ranging from shallow waters down to around 50 meters (164 feet).

Different species of Unicornfishes have different geographic distributions. For example, Naso annulatus is found in the western Pacific, from the Philippines to northern Australia, while Naso brachycentron is found in the eastern Pacific, from Mexico to Ecuador. Some species, such as Naso caesius and Naso thynnoides, have wide distributions throughout the Indo-Pacific.

Overall, Unicornfishes are an important and diverse group of fishes that play a key role in maintaining the health and biodiversity of coral reef ecosystems.

Warning

Unicornfishes have a sharp, scalpel-like spine located on either side of their tail base, just in front of the caudal fin. These spines are used as a defense mechanism against predators and can cause serious injuries to humans if not handled carefully.

If a human comes into contact with the scalpel of a Unicornfish, the spine can penetrate the skin and cause a painful and potentially dangerous wound. The wound can become infected and may require medical attention.

Therefore, if you are snorkeling, diving, or handling a Unicornfish, it is important to avoid touching or grabbing the tail base of the fish to prevent injury. If you do accidentally get stabbed by a Unicornfish’s scalpel, seek medical attention immediately to ensure proper treatment.