14 Honeycomb Cowfish

Honeycomb Cowfish (Acanthostracion polygonius) belong to the Ostaciidae family, typically known as boxfishes. The structure of fish in the family include many bones and are shaped like a square. They have small mouths and broom-like tails that help with swimming because the boxy shape weighs them down. The Honeycomb Cowfish, however, is a rare species and have heavy hexagonal scales that cover the whole body. One form of defense are the tiny horns that protrude over the eyes.  They typically grow between the range of 7 to 15 inches and are commonly found in water depth of 20-60 ft, meaning they inhabitant the neritic zone.

HoneyComb Cowfish CC BY SA 2.0

Location:

The habitat of Honeycomb Cowfish is the western Atlantic Ocean. They are found as far up along the coast of New Jersey and as far south as southern Brazil, but are most typically found in the Caribbean and Gulf of Mexico. These diurnal  animals prefer to reside in clear water with an average temperature of 22-270 C in coral reef habitats and vicinity. 

Anatomy:

A closer look at the biology of the fish shows the hexagonal scales are attached firmly to each other except around the head and tail of the fish. This allows for respiration and movement for the gills, fins, and eyes, and caudal peduncle. The color of the fish is also a unique characteristic; they are seen in blues and greens and yellows and browns. The dorsal edge has darker and/or irregular hexagons due to the opening of the scales.  Juvenile fish are more brightly colored and have shorter dorsal fins. The honeycomb scales are used for protection. Honeycomb fish feed on marine invertebrates, mainly shrimp, tunicates, and sponges. The structure of the small mouth is used to suck in small food particles. Their food sources are mainly sessile which are easier to find, as honeycomb cowfish are not active hunters. They have a solitary nature and are never seen in groups of more than 3 individuals. Typically, when grouping, the small school will be comprised of one male and two females. Not much is known about their reproductive nature, but many scientists conclude this grouping may be significant. It is known that they are open water mating fish which means they swim to the surface quickly to release gametes and then swim back down immediately.

 

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Cowfish Honeycomb By Amanderson2 CC BY SA

Like many fish, they undergo different life stages. For Honeycomb Cowfish they have two stages of juvenile and adult. Juveniles are rounder and brighter in color. They can also change color to protect themselves from predators. They do this by sending a signal via nerve impulse to Chromatophores, which are pigment cells in the scales. To learn more about this process watch this video.

Predators of Honeycomb Cowfish are larger fish, but usually cowfish are undesirable as food due to their external armor. As Honeycomb Cowfish grow into adulthood their colors fade and they become more triangular and rigid resulting in awkward swimming.  One way they protect themselves is by use of camouflage by blending into the colorful surrounding of coral reefs. When stressed, adults can brighten their colors to be more effectively hidden. When using camouflage, they remain stationary for long periods of time.

Overall, Honeycomb Fish are very unusual fish and use honeycomb-shaped scales as protective armor. They can also use their bright colors to blend into coral reefs to hide from predators and the boxy shape makes them undesirable to natural predators. Unfortunately, these fish are used to a great extent commercially as pets which can damper population sizes. By choosing their habitat close to coral reefs, they have easy access to food and shelter. These fish are really interesting. If you want to learn more about boxfishes, watch this video.

 

The information in this chapter is thanks to content contributions from Maddison Oulette

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A Student's Guide to Tropical Marine Biology by by Keene State College Students, BIO 381 Tropical Marine Biology is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.

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