What is the Difference Between Esca and Illicium?

The key difference between esca and illicium is their function and structure in the context of anglerfish predation:

• Illicium: It is the modified dorsal fin spine of anglerfish, which acts as a fishing pole with a tip that attracts prey. The illicium is the elongated first dorsal fin spine of the anglerfish, and it can be moved back and forth by distinct pairs of muscles.
• Esca: It is the fleshy growth located at the end of the illicium, which acts as a lure for other fish. The esca can have different shapes, resembling small animals, and it can be regenerated if lost. The luminescence of the esca is due to symbiotic bacteria that dwell in and around it, enclosed in a cup-shaped reflector containing crystals.

In summary, the illicium is the modified dorsal fin spine that acts as a fishing pole, while the esca is the fleshy lure located at the end of the illicium. Both structures play crucial roles in the predatory mechanisms of anglerfish.

Comparative Table: Esca vs Illicium

Here is a table comparing the differences between Esca and Illicium:

Both Esca and Illicium are structures used in the predatory mechanisms of anglerfish. They are important for the anglerfish's unique mode of predation, where the illicium serves as a fishing pole and the esca acts as bait.