Longhorn Cowfish (Lactoria cornuta) Care
The Longhorn Cowfish, Lactoria cornuta, is also known as the Yellow Boxfish. These fish come from Indo-Pacific, Red Sea, and East Africa regions. The Longhorn Cowfish can be different shades of yellow and is covered with white and blue dots. The body is an unusual boxy shape and it has two long “horns” on the top of the head, facing forward.
This species of blenny are omnivores and require a diet containing both meaty foods and plant-based foods, such mysis and brine shrimp and marine algae. They should be fed a couple of times a day. They are very slow eaters, so care should be taken to make sure they get enough food.
These fish can grow quite large and will do best in a fish-only tank of at least 220 gallons with non-aggressive tankmates. They will only be aggressive towards other longhorn cowfish.
NOTE: When stressed, Boxfish release a toxin called ostracitoxin from their mucous glands. This toxin can quickly kill everything in the tank. If caught quickly, you can sometimes reverse the toxin with activated carbon. If a boxfish is being bullied, is stressed, or appears ill, remove it from the tank immediately.
Approximate Purchase Size
Tiny: up to 3/4”
Small: 3/4” to 1”
Small-Medium: 1” to 1-1/2”
Medium: 1-1/2” to 2”
Medium-Large: 2” to 2-1/2”
Large: 2-1/2” to 3”
Extra Large: 3” to 3-1/2”
Extra Extra Large: over 3-1/2”