Janthinidae

Janthinidae is a family of pelagic sea snails, commonly known as violet sea snails or violet slugs. These gastropods are characterized by their striking violet coloration, which can range from deep purple to pale lavender. They are found in warm and tropical waters worldwide, drifting on the ocean's surface.

The most distinctive feature of Janthinidae is their method of flotation. They secrete a raft of mucus bubbles, which hardens and allows them to remain buoyant. This raft is crucial for their survival, as they are planktonic for most of their lives. They are often found in aggregations, sometimes in large numbers, particularly after storms.

Janthinidae are carnivores, feeding primarily on other planktonic organisms such as jellyfish, siphonophores, and other small invertebrates. They use their radula, a ribbon-like tongue with teeth, to scrape food from their prey. Their slow movement and passive drifting make them vulnerable to predators.

Reproduction in Janthinidae typically involves both sexual and asexual phases. Some species are hermaphroditic, possessing both male and female reproductive organs. The larval stage is planktonic, and as the snail grows, it develops its characteristic mucus raft.

The family Janthinidae includes several genera, such as Janthina, Recluzia, and Stomatia. Despite their beauty, these snails are rarely encountered by humans due to their pelagic lifestyle and the remote locations where they are found. Their presence is often an indicator of ocean currents.