Wentletrap
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, and it means spiral staircase. These snails are sometimes also called "staircase shells", and "ladder shells".
The family Epitoniidae belongs to the superfamily Epitonioidea. Since 2017 this family also includes the former families Janthinidae and Nystiellidae, all part of the informal group Ptenoglossa.
Epitoniidae is a rather large family, with an estimated number of species about 630.
Distribution
Wentletraps inhabit all seas and oceans worldwide, from the tropical zones to the Arctic and Antarctic zones.Shell description
Most species of wentletrap are white, and have a porcelain-like appearance. They are notable for their intricately geometric shell architecture, and the shells of the larger species are prized by collectors.The more or less turret-shaped shell consists of tightly-wound, convex whorls, which create a high, conical spiral. Fine or microscopic spiral sculpture is present in many species. The shells sometimes feature an umbilicus. Wentletrap 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 of the species in the family are small to minute, although some are larger, and overall the adult shell length in the family varies between 0.6 and 11.7 cm.
Within the genus Epitonium, the type genus of the family, the shell has predominantly axial sculpture of high, sharply ribbed "costae". These costae may offer some protection against other predatory snails, which would find it difficult or impossible to bore a hole in a shell with such obstructions.
Ecology
Wentletraps are usually found 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. Keen is most often cited. He observed that many wentletraps reveal a hint of purple body color, suggestive of carnivorous feeding. 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.
A sequence of a wentletrap feeding on an anemone has been published. 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
Genera within the family Epitoniidae include:Acirsa Mörch, 1857 Acrilla H. Adams, 1860Acrilloscala Sacco 1891 Alexania Strand, 1928 Alora Amaea H. & A. Adams, 1853 Boreoscala Kobelt, 1902- † Cavoscala Whitfield, 1892
- † Cerithiscala de Boury, 1887Chuniscala Thiele, 1928 Cingulacirsa Higo & Goto, 1993
- † Circuloscala de Boury, 1886 Cirsotrema Mörch, 1852 Clathroscala de Boury, 1890
- † Clathrus Agassiz, 1837 Claviscala de Boury, 1909
- † Confusiscala de Boury, 1909 Couthouyella Bartsch 1909 Crebriscala de Boury, 1909Cycloscala Dall, 1889Cylindriscala de Boury, 1909 Ecclesiogyra Dall, 1892 Eglisia Gray, 1842 Epidendrium A. Gittenberger & E. Gittenberger, 2005Epifungium A. Gittenberger & E. Gittenberger, 2005Epitonium Röding, 1798 Eulima Risso, 1826Filiscala de Boury, 1911
- † Foratiscala de Boury, 1887 Fragilopalia Azuma, 1972Funiscala de Boury, 1890
- † Gibboscala Kollmann, 2005 Globiscala de Boury, 1909
- † Goniscala Marwick, 1943 Gregorioiscala Cossman, 1912 Gyroscala de Boury, 1887 Iphitus Jeffreys, 1883Janthina Röding, 1798Kurodacirsa Masahito & Habe, 1975
- † Liapinella Guzhov, 2006 Mammiscala de Boury, 1909Minabescala Nakayama, 1994 Murdochella H. J. Finlay, 1926Narrimania Taviani, 1984Narvaliscala Iredale, 1936 Opalia H. & A. Adams, 1853 Opaliopsis Thiele, 1928Periapta Bouchet & Waren, 1986
- † Plicacerithium Gerasimov, 1992 Propescala Cotton & Godfrey, 1931
- † Proscala Cossmann, 1912 Punctiscala Philippi, 1844 Recluzia Petit de la Saussaye, 1853Rectacirsa Iredale, 1936Rutelliscala Kilburn, 1985Sthenorhytis Conrad 1862 Striatiscala de Boury, 1909Surrepifungium A. Gittenberger & E. Gittenberger, 2005Tenuiscala de Boury, 1887Tumidiacirsa de Boury, 1911
- † Turriscala de Boury, 1890 †
- Variciscala de Boury, 1909 Varicopalia Kuroda MS, 1960
Synonyms
Acrilla H. Adams, 1860: synonym of Amaea H. Adams & A. Adams, 1853Acutiscala de Boury, 1909 : synonym of Epitonium Röding, 1798Amiciscala Jousseaume 1912 : synonym of Epitonium Röding, 1798Asperiscala de Boury, 1909: synonym of Epitonium Röding, 1798Cinctiscala de Boury 1909 : synonym of Asperiscala de Boury, 1909Cirratiscala de Boury, 1909 : synonym of Epitonium Röding, 1798Clathroscala de Boury 1889 : synonym of Amaea H. Adams & A. Adams, 1853Clathrus Oken 1815 : synonym of Epitonium Röding, 1798Compressiscala Masahito & Habe 1976 : synonym of Gregorioiscala Cossmann, 1912Dannevigena Iredale 1936 : synonym of Cirsotrema Mörch, 1852Depressiscala de Boury 1909 : synonym of Epitonium Röding, 1798Foliaceiscala de Boury 1912 : synonym of Epitonium Röding, 1798Fragiliscala Azuma 1962 : synonym of Amaea H. Adams & A. Adams, 1853FragilopaliaAzuma 1972 : synonym of Amaea H. Adams & A. Adams, 1853- Glabriscala de Boury 1909 : synonym of Epitonium Röding, 1798Lampropalia Kuroda & Ito, 1961 : synonym of Cylindriscala de Boury, 1909Mazescala Iredale 1936 : synonym of Epitonium Röding, 1798Nipponoscala Masahito & Habe 1973 : synonym of Epitonium Röding, 1798Nodiscala de Boury 1889 : synonym of Opalia H. Adams & A. Adams, 1853Nystiella Clench & Turner, 1952 : synonym of Opaliopsis Thiele, 1928Plastiscala Iredale, 1936 : synonym of Acirsa Mörch, 1857 Problitora Iredale, 1931 : synonym of Alexania Strand, 1928 Sagamiscala Masahito, Kuroda & Habe, 1971 : synonym of Globiscala de Boury, 1909Scala Mörch, 1852 : synonym of Epitonium Röding, 1798Scalina Conrad, 1865 : synonym of Amaea H. Adams & A. Adams, 1853Spiniscala de Boury, 1909 : synonym of Epitonium Röding, 1798Turbiniscala de Boury 1909 : synonym of Epitonium Röding, 1798Viciniscala de Boury 1909 : synonym of Epitonium Röding, 1798