What Divers Should Know About Boxfish

Boxfishes, part of the Ostraciidae family and closely related to pufferfishes, stand out with their distinctive, squared bodies. These bony fish possess plate-like scales fused into a rigid, often triangular or box-like carapace, giving them their characteristic name. Their skin frequently displays intricate hexagonal or "honeycomb" patterns, with young individuals often exhibiting more vibrant colors and a rounder shape than the squarer adults. Among them, species like the scrawled cowfish can reach lengths of up to 50 centimeters.

This heavy armor limits boxfishes to slow, deliberate movements, often described as a 'rowing' manner. You'll encounter these intriguing creatures across the Atlantic, Indian, and Pacific oceans, typically in middle latitudes. Their robust build offers significant protection from most predators, but some boxfish, particularly those in the Lactophrys genus, employ an additional defense. When stressed, they can secrete a potent, water-soluble toxin, like pahutoxin, from their skin into the surrounding water. This chemical defense, while effective for the fish, serves as a good reminder for divers to observe respectfully and avoid disturbing them.