Reef Species & Ecology, Watercolor

Honeycomb Cowfish

Honeycomb Cowfish; Snorkeling at Klein Bonaire, 2018. Photo by Chuck Lauer Vose.
  • Common Name: Honeycomb Cowfish
  • Genus, species: Acanthostracion Polygonius
  • Family: Boxfish – Ostraciidae
  • Size: 7-15 in. (max:18 in.)
  • Depth: 20-80 ft.
  • Distinctive Features:
    1. Honeycomb pattern all over body
    2. sharp spines over the eyes
    3. sharp spines in front of the anal fin
  • Description: These fish can vary in color from greenish-blue to yellowish-white. They can change color and lighten or darken according to their surroundings.
  • Abundance & Distribution: Occasional eastern Florida, Bahamas, Caribbean; also north to New Jersey, Bermuda and South to Brazil. Not Reported Florida Gulf Coast.
  • Habitat & Behavior: Swims about reefs, blends in with background.
  • (Humann, P. , Deloach, N. 2014. 454-5p.).

These fish are tricky to photograph but really fun to paint! To photograph them, you really have to wait for them to come to you. This was an early favorite fish of mine – the colors are so beautiful and the horns on its head are really fun to see! Though I didn’t realize until I started working on this post that there are spines on their underside as well. Even though I actually included them in my watercolor painting, I thought it was part of their fins. You can just make out the spines in a few of the pictures below.

Diet: The Honeycomb Cowfish eats small invertebrates like shrimp, tunicates, and sponges. Their small round, tube-like mouth allows them to suck up small food particles (A Student’s Guide to Tropical Marine Biology).

Locomotion: Because of their boxy, inflexible shape, Boxfish swim by moving only their caudal (tail) fin. This form of locomotion is called ostraciiform swimming. The tail fin is almost totally transparent and moves so rapidly, this can make it look as though the fish is just hovering over the reef and moving through invisible means.

From anguilliform to ostraciiform the swimmers' body length acts against the water and the amplitude of body movement lowers. In reverse the flap frequency rises (figure source Sfakiotakis et al. [10]).
From anguilliform to ostraciiform the swimmers’ body length acts against the water and the amplitude of body movement lowers. In reverse the flap frequency rises (figure source Sfakiotakis et al.).

Predation: Although they are somewhat awkward swimmers, they are well protected by their coloration and by an armor-like covering of connected hexagonal scales and the spines above their eyes and on their underside (Florida Museum of Natural History).

Mating and Reproduction: To the best of my recollection, I have only seen them swimming about solo – which is common for this species. However, when mating, they are know to form small groups consisting of one male and two females. Honeycomb Cowfish are open water mating fish that release their gametes (sperm and egg) into the water column to mingle and be fertilized (A Student’s Guide to Tropical Marine Biology). These eggs float away and become part of the ocean food-chain as plankton (Snyderman, M. 2004).

Sources Cited:

Acanthostracion polygonius. Florida Museum of Natural History”. Accessed October 2021.

A Student’s Guide to Tropical Marine Biology by by Keene State College Students, BIO 381 Tropical Marine Biology. Accessed October 2021.

Fremerey, M. & Fischheiter, L. & Mämpel, J. & Witte, Hartmut. (2010). Locomotion study of a single actuated, modular swimming robot. 138. 227-237. 10.2495/DN100201. [accessed 26 Oct, 2021]

Giant, M.C., & Snail, R.W. 2015. UWI The Online Guide to the Animals of Trinidad and Tobago Ecology Marisa cornuartietis ( Giant Ramshorn Snail ). Accessed 26 Oct, 2021.

Humann, P. , Deloach, N. 2014. Reef Fish Identification; Florida Caribbean Bahamas. 4th Edition. Jacksonville, Fl, New World Publications inc.

Snyderman, Marty. Fascinating, but Complicated: Mating and Reproduction in the Marine Realm. December 15, 2004. Accessed 26 Oct, 2021.