How do the head shapes and mouths of mormyrid fishes vary?

The Mormyridae family exhibits significant diversity in head shape and mouth structure, which is closely linked to their specific feeding habits.1

• Insectivores: Many species that feed on insects possess narrow heads and small mouths located at the tip of a long, curved, tubular snout. This specialized anatomy allows them to probe for prey among rocks or within soft mud.21
• Piscivores: Species that prey on other fish typically feature larger mouths and shorter snouts.1
• Other Variations: Beyond these specialized forms, some mormyrids are characterized by protruding lower lips or short, rounded snouts. Notably, the elephant-snout fishes (Gnathonemus) are distinguished by having their mouths positioned at the end of a long, trunklike snout.2