Necklace-worms

The necklace-worms (Family Syllidae) are a spectacular group whose complexity challenges species identification. Currently, many members of this family are in a state of taxonomic turmoil. Necklace-worms have remarkably diverse modes of reproduction, responding to many of the same internal and external cues that initiate spawning in the sea-nymphs, p. 144. However, unlike many sea-nymph species, most necklace-worms can reproduce more than once. Most necklace-worms are likely carnivorous. The muscular gizzard-like proventricle (glandular tube) is a unique aspect of the digestive system. Its pumping action is the main reason why the necklace-worm can feed by sucking. Less obvious is the proventricle’s importance in hormone production, which in part regulates the worm’s sexual development.