7 Fish with Horns

In this fascinating article, Louise highlights seven fish species that have unique horn-like features. While horns are typically associated with land-dwelling creatures, these underwater inhabitants also possess striking bony structures that resemble horns. From the bluespine unicorn tang with its prominent forehead horn to the longhorn cowfish and its cow-like horns, each fish on this list boasts its own distinctive characteristics. Discover the intriguing appearance and habitats of these seven fish with horns and gain a deeper appreciation for the diversity of marine life.

Fish with Horns

Fish with horns may not be the first thing that comes to mind when thinking about aquatic creatures, but they do exist! These unique fish species have fascinating features that resemble horns, adding to their charm and intrigue. In this article, we will explore seven different fish with horns and learn interesting facts about each of them.

Bluespine Unicorn Tang

Scientific Name: Naso unicornis

One of the most captivating fish species in the Indo-Pacific region is the bluespine unicorn tang. This fish stands out with its bluish-gray body and two blue spines on each side of the base of its tail. The most distinct feature, however, is the large bony horn on its forehead. This horn only appears on big fish, making it a unique characteristic. Adults of this species can grow up to 70 cm in length, making them quite a sight to behold.

Moorish Idol

Scientific Name: Zanclus cornutus

The Moorish idol is another fish species with horn-like projections. These fish can be found in the waters of the Indo-Pacific region and are easily identifiable by their bold black and yellow colors, as well as their long, trailing dorsal spine. The males of this species have small, boney projections above their eyes, resembling horns. Moorish idols have a flattened, disc-like body and a tubular snout, giving them a unique appearance. They primarily feed on sponges, coral polyps, and various other invertebrates in their natural habitats.

Whitemargin Unicornfish

Scientific Name: Naso annulatus

The whitemargin unicornfish, also known as the ringtailed unicornfish or the short-horned unicornfish, is a large tropical fish that inhabits the Indo-Pacific region. This species can grow up to 100 cm in length, making it one of the largest in its family. One of the most curious features of this fish is the bony protrusion in front of its eyes, resembling a horn. While these fish start by consuming green algae in shallow, clear water lagoons, they transition to eating soft zooplankton as adults.

Longhorn Cowfish

Scientific Name: Lactoria cornuta

The longhorn cowfish is an easily recognizable species with a pair of long horns protruding from its head, resembling cow or bull horns. These fish can be found in the Indo-Pacific region and can reach lengths of up to 50 cm. Their habitats include coral reefs, lagoons, flats, and estuaries, where they actively contribute to maintaining the health and balance of the reef ecosystem. The horns of the longhorn cowfish serve multiple functions, including defense against potential predators.

Humpback Unicornfish

Scientific Name: Naso brachycentron

Belonging to the same genus as the bluespine unicorn tang, the humpback unicornfish is found in the Indian and western Pacific Oceans. Male humpback unicornfish have a bony protrusion in front of their eyes, sometimes extending past their mouths. In contrast, females may only have a small bump. These fish can reach a maximum length of 90 cm and have gray upper bodies and heads, with yellowish or whitish lower bodies.

Fourhorn Sculpin

Scientific Name: Myoxocephalus quadricornis

The fourhorn sculpin is a ray-finned fish that can be found in marine, brackish, and freshwater habitats across the Holarctic region. Their distinctive feature is a head that is larger than their body, with four bony structures protruding from it. However, these features are not present in freshwater variations of the species. The average length of this fish is between 20 to 30 cm in marine habitats, but only around 15 cm in lakes. The fourhorn sculpin feeds on invertebrates, small fishes, and fish eggs.

Shorthorned Unicornfish

Scientific Name: Naso brevirostris

The shorthorned unicornfish is an unusual-looking fish found in the Indian and Pacific Oceans. These fish can be identified by their short snout, with adults having distinct bony protuberances in front of their eyes. Their coloration can range from blueish-gray to olive-brown. Shorthorned unicornfish prefer to live in lagoons and seaward reefs at depths of up to 46 meters. Their diet consists of algae as juveniles and gelatinous zooplankton as adults.

Interesting Facts About Fish with Horns

  • Unicorn fishes, such as the bluespine unicorn tang, are part of the Naso genus, but not all species have prominent horns.
  • The horns of fish like the longhorn cowfish serve as both a defensive weapon and a threat display.
  • Moorish idols primarily feed on sponges, coral polyps, and other invertebrates found in the deeper parts of their habitats.
  • The whitemargin unicornfish changes its diet as it grows from consuming green algae to soft zooplankton.
  • The humpback unicornfish exhibits sexual dimorphism, with males having more pronounced bony protrusions than females.
  • The horns of the fourhorn sculpin are not present in freshwater variations of the species.
  • The shorthorned unicornfish feeds on algae as juveniles and gelatinous zooplankton as adults.


Fish with horns are a curious and fascinating group of aquatic creatures. From the bluespine unicorn tang to the shorthorned unicornfish, each species possesses unique characteristics that set them apart. Whether it’s a bony horn, protuberances, or long horns, these fish demonstrate the remarkable diversity found in the underwater world. Exploring and learning about these intriguing creatures adds another layer of appreciation for the wonders of nature.

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