User:Fugumallow/Tetraodontidae

Morphology
Tetraodontiforms, or pufferfish, are most significantly characterized by the beak-like four teeth- regarding the name "tetra-" for four and odont-" for tooth. The top and bottom arches are fused together with a visible midsagittal demarcation, which are used to break apart and consume crustaceans. The lack of ribs, a pelvis, and pectoral fins are also unique to pufferfish. The notably missing bone and fin features are due to the pufferfish' specialized defense mechanism, expanding by sucking in water through an oral cavity.

Pufferfish have many varied structures of caltrop-like dermal spines, which account for the replacement of typical fish scales, and can range in coverage from the entire body to leaving the frontal surface with no spines.