Wentletraps are small, often white, very high-spired, predatory or ectoparasitic sea snails, marine gastropod mollusks, in the family Epitoniidae.
The word wentletrap originated in Dutch (wenteltrap), and it means spiral staircase. These snails are sometimes also called "staircase shells", and "ladder shells".
The Epitoniidae family belongs to the superfamily Epitonioidea, which also includes the Janthinidae (the pelagic purple snails) and the family Nystiellidae, all part of the informal group Ptenoglossa. It is a rather large family with an estimated number of species over 630.
Wentletraps inhabit all seas and oceans worldwide, from the tropical zones to the Arctic and Antarctic zones.
Wentletraps are notable for their intricately geometric shell architecture. The more or less turret-shaped shell consists of tightly-wound (sometimes loosely coiled), convex whorls which create a high, conical spiral. Spiral ribs (also called "striae") often occur. These shells often contain an umbilicus. The shells have a roundish or oval aperture, but its inner lip is often reduced to strip of callus. The round and horny operculum is paucispiral and fits the aperture tightly. Most species are small to minute with length between 0.6 and 11.7 cm.
Within the genus Epitonium the shell has high, sharply ribbed sculpture with predominantly axial sculpture, known as "costae". These offer some protection against other predatory snails who find it hard to bore a hole in such a shell.
Most species of wentletrap are white, and have a porcelain-like appearance. These shells are prized by collectors.
Wentletraps are usually found usually on sandy bottoms near sea anemones or corals, which serve as a food source for them. Some species are foragers and search for anemones.
Little is known about the biology of most wentletraps. Many wentletraps reveal a hint of purple body color, suggestive of carnivorous feeding (Keen, 1958). The animal can exude through its salivary gland a pink or purplish dye that may have an anaesthetic effect on its prey.
Keen also cited direct observation of a wentletrap feeding by insertion of its proboscis into a sea anemone. These snails also prey on corals and other coelenterates.
Female wentletraps lay egg capsules that are bound together with a supple string. The young emerge from these capsules as free-swimming larvae.
Genera within the family Epitoniidae include:
- Acirsa Mörch, 1857
- Acrilla H. Adams, 1860
- Acrilloscala Sacco 1891
- Alexania Strand, 1928
- Alora (H. Adams, 1861)
- Amaea H. & A. Adams, 1853
- Asperiscala de Boury, 1909
- Berthais Melvill, 1904 
- Boreoscala Kobelt, 1902 (possibly a synonym of Cirsotrema)
- Chuniscala Thiele, 1928
- Cingulacirsa Higo & Goto, 1993
- Cirsotrema Mörch, 1852
- Claviscala de Boury, 1909
- Compressiscala Masahito (Prince) & Habe 1976
- Constantia Adams 1860 
- Couthouyella Bartsch 1909
- Crebriscala de Boury, 1909
- Cycloscala Dall, 1889 <:small>
- Cylindriscala de Boury, 1909
- Depressiscala de Boury 1909
- Ecclesiogyra Dall, 1892 
- Eglisia Gray, 1842
- Epidendrium A. Gittenberger & E. Gittenberger, 2005
- Epifungium A. Gittenberger & E. Gittenberger, 2005
- Epitonium Röding, 1798
- Foratiscala de Boury 1887
- Funiscala de Boury, 1890
- Globiscala de Boury, 1909
- Gregorioscala Cossman, 1912
- Gyroscala de Boury, 1887
- Iphitus Rafinesque 1815 
- Kurodacirsa Masahito & Habe, 1975
- Minabescala Nakayama, 1994
- Murdochella Finlay, 1927 
- Narrimania Taviani, 1984
- Narvaliscala Iredale, 1936
- Nodiscala de Boury 1889
- Obstopalia Iredale, 1936
- Opalia H. & A. Adams, 1853
- Papuliscala de Boury, 1909 
- Periapta Bouchet & Waren, 1986
- Plastiscala Iredale, 1936
- Problitora Iredale, 1931
- Punctiscala Philippi, 1844
- Rutelliscala Kilburn, 1985
- Sagamiscala Masahito, Kuroda & Habe, 1971
- Sthenorhytis Conrad 1862
- Surrepifungium A. Gittenberger & E. Gittenberger, 2005
- Tasmalira Dell 1956 
- Variciscala de Boury, 1909
- Varicopalia Kuroda MS, 1960 (nomen nudum)
- Genera brought into synonymy 
- Acutiscala de Boury, 1909 : synonym of Epitonium Röding, 1798
- Amiciscala Jousseaume 1912 : synonym of Epitonium Röding, 1798
- Cinctiscala de Boury 1909 : synonym of Asperiscala de Boury, 1909
- Cirratiscala de Boury, 1909 : synonym of Epitonium Röding, 1798
- Clathroscala de Boury 1889 : synonym of Amaea H. Adams & A. Adams, 1853
- Clathrus Oken 1815 : synonym of Epitonium Röding, 1798
- Dannevigena Iredale 1936 : synonym of Cirsotrema Mörch, 1852
- Foliaceiscala de Boury 1912 : synonym of Epitonium Röding, 1798
- Fragiliscala Azuma 1962 : synonym of Amaea H. Adams & A. Adams, 1853
- FragilopaliaAzuma 1972 : synonym of Amaea H. Adams & A. Adams, 1853
- Glabriscala de Boury 1909 : synonym of Epitonium Röding, 1798
- Lampropalia Kuroda & Ito, 1961 : synonym of Cylindriscala de Boury, 1909
- Mazescala Iredale 1936 : synonym of Epitonium Röding, 1798
- Nipponoscala Masahito (Prince) & Habe 1973 : synonym of Epitonium Röding, 1798
- Nystiella Clench & Turner, 1952 : synonym of Opaliopsis Thiele, 1928
- Scala Mörch, 1852 : synonym of Epitonium Röding, 1798
- Scalina Conrad, 1865 : synonym of Amaea H. Adams & A. Adams, 1853
- Spiniscala de Boury, 1909 : synonym of Epitonium Röding, 1798
- Turbiniscala de Boury 1909 : synonym of Epitonium Röding, 1798
- Viciniscala de Boury 1909 : synonym of Epitonium Röding, 1798