Epitonium tinctum (Carpenter, 1864)

Common name(s): Tinted wentletrap, white wentletrap, painted wentletrap
Synonyms: Nitidiscala tincta, Nitidiscala eelense, Epitonium subcornatum, Epitonium indianorum tincta Epitonium tinctum
Class Gastropoda 
Order Neotaenioglossa 
Family Epitoniidae 
Epitonium tinctum, about 1.5 cm long, from intertidal at San Simeon, CA.  The shell was among the bases of Anthopleura elegantissima anemones.
(Photo by: Dave Cowles, August 2010 )
Description: Wentletrap shells (family Epitoniidae) usually are white, tall and narrow, and have an impressed suture between the whorls.  They have no spiral ridges.  The aperture is nearly circular, and the inside is not pearly.  This species has 8-14 thin axial lamellae which are continuous from whorl to whorl.  The lamellae curve evenly, without sharp angles or projections near the sutures.  It has a small purplish or brown line near the suture between the whorls (not readily visible here).  There is no spiral ridge or sharp shoulder around the base of the body whorl.  The spire is tall, and the shell height is much more than twice the diameter.  The shell usually has 6 or more whorls.  Shell length up to 3.2 cm but usually not more than 1.5 cm.  Northern populations in California are larger than southern ones and subtidal individuals are larger than intertidal. (Or, E. indianorum is larger, more offshore, and sometimes confused with this species).
 

How to Distinguish from Similar Species:Opalia species such as Opalia montereyensis have a strong shoulder or spiral ridge along the base of the body whorl.  Some other wentletrap species have well over 14 axial lamellae or the lamellae have sharp angles or spines near the suture. Epitonium indianorum grows larger, is largely offshore and subtidal, and does not have the brown or purple line near the suture.
 

Geographical Range: Southern Alaska to Bahia Magdalena, Baja California, Mexico
 

Depth Range: Intertidal to 45 m
 

Habitat: In sand near anemones, especially Anthopleura; so it is presumably mostly intertidal.
 

Biology/Natural History: As with other wentletraps, this species feeds on anemones.  It is usually found in sand near the base of Anthopleura elegantissima or Anthopleura xanthogrammica, to which the species is strongly attracted.  At high tide (twice a day) it feeds on the tips of the anemone tentacles; then at low tide burrows into the sand.  Living wentletraps contain a purple, toxic dye.  The dye appears to be an anesthetic and it is thought that the snail may use it to relax the anemone tissues before feeding.  While feeding it extends its proboscis which may be longer than the shell.  The radula is extended with the proboscis.

The snail shows some attraction to Urticina lofotensis and Epiactis prolifera and it will feed on these species, but the attraction is less than that for Anthopleura.  These anemones also show a stronger retraction when bitten by the snail, so perhaps the snail anesthetic is most effective with Anthopleura.  They are not attracted to Corynactis californica and are repelled by Metridium senile.  Some snails contacting Metridium senile were killed.

The species produces sand-encrusted egg capsules which are strung together by a thread.  The capsules are laid among their anemone prey.

Small Pagurus hirsutiusculus hermit crabs frequently inhabit the empty shells.

The name "wentletrap" is from the German or Dutch word for "winding staircase".


 
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References:

Dichotomous Keys:
  Carlton, 2007
  Kozloff, 1987, 1996

General References:
  Harbo, 1997
  Hinton, 1987
  (Johnson and Snook, 1955)--probably as E. bellastriatum
  McConnaughey and McConnaughey, 1986
  Morris, 1966
  Morris et al., 1980
  Niesen, 1997
  Rice, 1973
  Ricketts et al., 1985

Scientific Articles:
 

Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors:
 

Size

This photo beside my finger shows the very small size of the shell.  Total length is about 1.5 cm.  Note also the horny operculum with only a small amount of spiral ("paucispiral") pattern.


Authors and Editors of Page:
Dave Cowles (2010):  Created original page
CSS coding for page developed by Jonathan Cowles (2007)

Rosario Invertebrates web site provided courtesy of Walla Walla University