Why are tetraodontiform jaws useful for eating hard-shelled prey?

Tetraodontiforms are highly adapted for consuming hard-shelled prey, such as crustaceans, mollusks, and echinoderms, primarily due to their specialized dentition and jaw structure. Many species in this order possess massive, well-developed teeth that are often fused together to form a powerful, parrotlike beak.1

This fusion of teeth with the jawbones provides the structural strength necessary to crush the protective shells of their prey. By utilizing these robust, crushing jaws, these fish can effectively access food sources that are unavailable to less-specialized species. While some members of the order, such as the ocean sunfishes, have evolved to feed on soft-bodied invertebrates, the order as a whole is characterized by these elaborative trends in tooth size and jaw development, which serve as a primary adaptation for their opportunistic predatory habits.21