Figure 5.

Model showing the evolutionary adaptations of toxin proteins and their expression in nemerteans with different feeding strategies. (A) A nemertean scavenger feeds on a fish carcass using the cocktail of proteases and other enzymes to macerate the tissue before ingestion, while toxins in the epidermis are used for defense. (B) A pilidiophoran that lacks a stylet apparatus captures a polychaete using paralytic toxins recruited into the proboscis. The proteases and other enzymes help the toxins reach their targets rapidly, and also facilitate a pre-digestion. (C) A hoplonemertean, such as A. lactifloreus, uses its venom apparatus to overpower an isopod crustacean with its prey-piercing stylet and toxins expressed in the proboscis.