Grand Coral Worm Snail

Thylacodes grandis is a species of sea snails, marine gastropod mollusks in the family Vermetidae, the worm snails or worm shells.

This gastropod is often confused with a sea worm because it lives in a tube-shaped shell. It is characterized by its large size and its black color marked with a pattern of many white lines, thin and interwoven. This tube develops on the surface of the coral and not embedded in it as one might think. The tube is not closed by a cap. The outer part of the tube is usually colonized by sponges among others. It feeds on long filaments covered in sticky mucus and captures plankton. He lives on the coral reef. Size 20 - 40 cm, depth 10 - 20 m.

Reproduction: It is sexual, there are males and females. Fertilization is internal, the released spermatozoa are captured by the females. The larvae are released in open water, they have a shell. After fixation they develop on the substrate.