The picture shows the Smooth Trunkfish (Lactophrys triqueter), member of the order of the tetraodontiformes. Some members of this order contain a powerful toxin which is named after these fish: tetrodotoxin.

The structure of tetrodotoxin is shown on the lower right hand side. The structure on the upper left side shows another powerful toxin from marine organisms, saxitoxin.

This fish likes chemistry, you can even see the formula of a polycyclic hydrocarbon on its skin!