Anglerfish

Anglerfish are a diverse group of marine fishes in the order Lophiiformes. They are best known for the illicium, a modified dorsal spine that bears the esca, a fleshy lure used to attract prey. In many species the esca and surrounding tissues host bioluminescent bacteria that produce light in the dark deep sea, drawing potential prey within reach. Anglerfish are found worldwide, from shallow coastal areas to the deep ocean, with the deepest species inhabiting the aphotic zone.

Morphology and feeding: Anglerfish show a range of forms, but many share a large head, an enormous mouth, and a body adapted to ambush predation. The jaws can open very wide, and the stomachs are expandable to accommodate large prey. The illicium and esca function as a living lure, enticing prey close enough to strike. Their bodies are often compact or laterally compressed, sometimes with elongated appendages and spines that help camouflage the fish as they wait for prey.

Reproduction: Reproductive strategies are highly variable. In many deep-sea lineages, males are vastly smaller than females and may become parasitic, attaching to a female and fusing with her tissues so that the male provides sperm for life. This extreme sexual dimorphism helps ensure fertilization in sparsely populated habitats. Eggs are typically released into the water in gelatinous masses, producing free-swimming larvae that disperse before maturing into adults.