Expert Only

Longhorn Cowfish

Lactoria cornuta

(0 Reviews)

Longhorn Cowfish

Expert Only

Longhorn Cowfish

Lactoria cornuta

(0 Reviews)

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Longhorn Cowfish Care Facts

Size: 1.5-2 inches
Care Level: Expert
Temperment: Peaceful
Diet: Omnivore
Origin: Indo-Pacific
Acclimation Time: 3+ hours
Reef Safe: Yes
Coral Safe: Yes
Invertebrate Safe: Monitor
Minimum Tank Size: 100 gallons

The Long Horned Cowfish,  Lactoria cornuta, is also known as the Longhorn Cowfish, Yellow Boxfish, or Polka Dot Cowfish. This fish is a variety of Boxfish with characteristic "horns" protruding from its head resembling a bull or cow. Though in its juvenile stage, the "horns" are yet not developed. The lovable Long Horned Cowfish is native to the Indo-Pacific Oceans and is a yellow/tan color with blue and white speckles. This reef fish grow up to 20 inches in the wild, while aquarium specimens may reach up to ten inches. They should be kept in a tank of at least 100 gallons with a sandy substrate and plenty of live rock and natural algae.  The Long Horned Cowfish is a fickle animal and should be kept by experienced aquarists. Similar to other Boxfish species, will exude a toxic poison through their skin if threatened, potentially deadly to other tank inhabitants. It is best not to be housed with other  Cowfish or Boxfish species, as it will become territorial and may become aggressive. It is generally temperate with corals and invertebrates but may be caught nibbling on tubeworms. They are slow swimmers and should be given a low water flow. They also should not be housed with aggressive eaters as they are also slow eaters, and may not be able to compete for food. They should be fed an omnivorous diet, consisting of meaty foods including raw shrimp, bloodworms, chopped clams, mussels, snails, tunicates, and fish. They are not picky eaters and will quickly become adapted to a variety of prepared aquarium foods and an occasional algae wafer and herbivore preparations. The Long Horned Cowfish is often a favorite in the tank because of its endearing and unique appearance.

Longhorn Cowfish Care Guide

The Longhorn Cowfish (Lactoria cornuta) is a unique and fascinating addition to any saltwater marine aquarium. This species is native to the tropical waters of the Indo-Pacific region, where it inhabits coral reefs and lagoons.

Habitat of the Longhorn Cowfish

Longhorn Cowfish are found in coral reefs and lagoons, preferring areas with plenty of hiding spots, such as rocks and coral formations. In captivity, they thrive in well-established saltwater aquariums with ample hiding places and open swimming areas.

Reef Compatibility of the Longhorn Cowfish

The Longhorn Cowfish is not considered reef-safe as it may nip at corals and other invertebrates, especially smaller ones. Therefore, it is best kept in fish-only or FOWLR (Fish Only With Live Rock) aquarium setups.

Size and Lifespan of the Longhorn Cowfish

Longhorn Cowfish can grow up to 20 inches (50 cm) in length in the wild, although in captivity, they typically reach around 12 inches (30 cm). They have a relatively long lifespan; they can live up to 10 years or more with proper care.

Diet of the Longhorn Cowfish in Captivity

These fish are omnivores, feeding on a varied diet consisting of meaty foods and algae. In captivity, they should be offered a diet that includes live or frozen brine shrimp, mysis shrimp, chopped seafood, and algae-based foods. Providing a varied diet will help ensure their nutritional needs are met.

Aquaculture and Availability of the Longhorn Cowfish

Longhorn Cowfish are not commonly aquacultured, so specimens available in the aquarium trade are usually wild-caught. They are occasionally available to hobbyists through reputable online retailers such as

Compatibility of the Longhorn Cowfish with Other Fish and Invertebrates

Longhorn Cowfish have a peaceful temperament but may become aggressive towards smaller fish or those with similar body shapes. They are generally compatible with larger, peaceful fish species such as tangs, angelfish, and triggers. However, caution should be exercised when choosing tank mates to avoid aggression and territorial disputes.

Sexual Dimorphism of the Longhorn Cowfish

No known external differences exist between male and female Longhorn Cowfish.

Juvenile to Adult Coloration Changes in the Longhorn Cowfish

Juvenile Longhorn Cowfish typically have a bright yellow body with blue spots. As they mature, their coloration may change to a more muted yellow or brownish hue, with the blue spots becoming less pronounced.

Temperament of the Longhorn Cowfish

Longhorn Cowfish are generally peaceful but can become territorial, especially towards other cowfish or fish with similar body shapes. They may also exhibit aggressive behavior if they feel threatened or stressed.

Detailed Tank Requirements of the Longhorn Cowfish

  • Minimum Tank Size: 180 gallons for a single Longhorn Cowfish.
  • Water Conditions:
    • pH: 8.1 - 8.4
    • Salinity: 1.020 - 1.025
    • Water Temperature: 72°F - 78°F
    • Water Flow: Moderate to high flow is preferred

Other Common Names for the Longhorn Cowfish

  • Horned Boxfish
  • Thornback Cowfish

Five Compatible Tank Mates for the Longhorn Cowfish

Why Buy Longhorn Cowfish from

  • Quality Assurance: Each fish is carefully selected and acclimated to ensure optimal health and condition.
  • Wide Selection: offers diverse marine fish, including rare and exotic species like the Longhorn Cowfish.
  • Expert Advice: The website provides valuable resources and expert guidance to help hobbyists create and maintain thriving marine aquariums.
  • Convenience: With convenient online ordering and reliable shipping, customers can have their desired fish delivered directly to their doorstep.

In conclusion, the Longhorn Cowfish is a captivating species that adds character to any saltwater aquarium. With proper care and suitable tank mates, these fish can thrive in captivity, delighting aquarists with their unique appearance and behavior. If you're considering adding a Longhorn Cowfish to your marine aquarium, provide them with the appropriate habitat, diet, and companionship to ensure their health and well-being.

Expert Only: Items designated as expert only require special care such as a species specific environment, special diet or care, and an expert level, experienced aquarist. Not for beginners. Expert Only items qualify for our live arrival guarantee only, and are exempt from our extended 8 day guarantee.

Beautiful fish

Reviewed by: Maria Robles on May 1, 2024

Excellent so much personality lots of fun kids love this one they call him alien follows their finger I told them they could train him

Reviewed by: Malissa Cruickshanks on April 17, 2024

Reviewed by: Christopher Weekes on Nov. 14, 2023

Wonderful little fish and very active

Reviewed by: Mary Fetterley on Oct. 26, 2023

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