| Janthina | |
|---|---|
 | |
| A drawing of a live Janthina janthina with its bubble raft intact | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Caenogastropoda |
| Superfamily: | Epitonioidea |
| Family: | Epitoniidae |
| Genus: | Janthina Röding, 1798 |
| Species | |
See text | |
| Synonyms [1] | |
| |
Janthina is a genus of small to medium-sized pelagic or planktonic sea snails, marine gastropod molluscs in the family Epitoniidae. [1] [2]
Species in this genus occur worldwide in tropical, subtropical and warm seas.
These snails are pelagic and live at the surface of the ocean. Adult snails may not be capable of swimming, and die when they are detached from their rafts; Janthina janthina larvae, however, actively swim in the water column. [3]
The adult snails prey upon (and live near to) one of several species of pelagic animals loosely known as jellyfish. More specifically they eat the medusae of free-swimming Cnidaria, in particular the genus known as "by-the-wind sailors", Velella .
The snails are able to float securely because they create a raft of clear chitin around air bubbles formed near the ocean surface. They anchor to this raft using their foot. [3] The snails do not have an operculum.
These snails are frequently washed ashore during storms. [4]
The common names for this genus derive from the light purple or violet color of the shells and the violet-colored bodies. The other genus in the family, Recluzia , has olive-tan colored shells.
The five extant species of the genus Janthina
This genus has accumulated a very large number of species names over the centuries. Most of the names that have been given are in fact synonyms of just a few species which have world-wide distributions in tropical waters. Experts disagree about some details of the synonymy.
Species within the genus Janthina include: [5]
Bulla is a genus of medium to large hermaphrodite sea snails, shelled marine opisthobranch gastropod molluscs. These herbivorous snails are in the suborder Cephalaspidea, headshield slugs, and the order Opisthobranchia.
Buccinum is a genus of medium-sized sea snails, marine gastropod molluscs in the family Buccinidae, the true whelks.
Trochus is a genus of medium-to large-sized, top-shaped sea snails with an operculum, of the family Trochidae, the top snails.
Thais, sometimes known by the common names dog winkles or rock shells, is a genus of medium to large predatory sea snails with an operculum, marine gastropod mollusks in the family Muricidae.
Tonna is a genus of large sea snails, marine gastropod molluscs in the family Tonnidae, the tun or cask shells.
Neritina, is a genus of small aquatic snails with an operculum in the family Neritidae, the nerites. They are as well marine, as brackish water, and sometimes freshwater gastropod mollusks
Bursa is a genus of large sea snails, marine gastropod molluscs in the family Bursidae, the frog snails or frog shells.
Polinices is a genus of predatory sea snails, marine gastropod molluscs in the subfamily Polinicinae of the family Naticidae, commonly known as moon snails.
Natica is a genus of small to medium-sized predatory sea snails, marine gastropods in the subfamily Naticinae of the family Naticidae, the moon snails. The genus was erected by Giovanni Antonio Scopoli in 1777.
Cymatium is a genus of small to large predatory sea snails, marine gastropod mollusks in the family Cymatiidae.
Patella is a genus of sea snails with gills, typical true limpets, marine gastropod mollusks in the family Patellidae, the true limpets.
Pyrene is a genus of small sea snails, marine gastropod mollusks in the family Columbellidae.
Cassis, common name the helmet shells, is a genus of very large sea snails, marine gastropod mollusks in the family Cassidae, the helmet shells and their allies. This is the type genus of the subfamily Cassinae.
Fusus is a genus of small to large sea snails, marine gastropod molluscs in the family Fasciolariidae, the spindle snails and tulip snails.
Strigatella is a genus of sea snails, marine gastropod mollusks in the subfamily Strigatellinae of the family Mitridae.
Janthina globosa is a species of holoplanktonic sea snail, a marine gastropod mollusk in the family Epitoniidae, the violet snails or purple storm snails.
Monoplex is a genus of predatory sea snails, marine gastropod mollusks in the family Cymatiidae.
Ranularia is a genus of predatory sea snails, marine gastropod mollusks in the family Cymatiidae.
Distorsio is a genus of medium-sized sea snails, marine gastropod mollusks in the family Personidae, the Distortio snails.
