murex shells

  Thais lacera
(Born, 1778)

Relevant Synonyms
Purpura carinifera Lamarck, 1822
Thais carinifera (Lamarck, 1822)
Mancinella mutabilis Link, 1807


 photo: S. Gofas / Coll. G. Spada    

Shell massive, solid, of 5-6 whorls, of which the body whorl makes most of the volume. Whorls with strong triangular knobs on a spiral keel; body whorl with an additional subsutural keel with projecting knobs and with a few indistinct spiral cords; the entire surface with fine, irregular spiral striae. Umbilical chink surrounded by a broad thickened rim. Aperture ovate, with the simple outer lip grooved spirally inside juveniles, smooth inside in well-grown specimens, terminating anteriorly in a small, short siphonal canal.

color : outside of a plain greyish or yellowish tan color, inside of aperture pale orange, juveniles with darker lines in grooves inside the outer lip.

common size : 50-60 mm.

It is distinguished from the native Thais haemastoma (Linnaeus, 1758) by having a strong keel which gives the spire a pagoda-like aspect, and in having a much paler color inside the aperture. Rapana venosa and Rapana rapiformis both have a flatter spire and much more swollen aperture.

Thais lacera lays clusters of cylindrical egg capsules attached to the substrate, which differ from capsules of the native Stramonita haemastoma (Linnaeus, 1758) in being rounded and poined at their tip, instead of flaring and rectangular. The larvae are pelagic, planktotrophic. Hanafy (1996) studied on Egyptian populations of this species the incidence of imposex (an anomaly also found in other Muricidae, induced by contaminants from anti-fouling paints used on ships, and where the females develop a non-functional penis).

habitat : on rocks, near sea level.

1st Mediterranean record
Jaffa, Israel, 1977 [1928].

Worldwide: Indian Ocean and Persian Gulf, but not the Red Sea; recorded as common in the Suez Canal (Tomlin, 1927) from which it has reached the northern part of the Red Sea (Singer and Mienis, 1991). Mediterranean: recorded first from Jaffa, Israel as Thais carinifera in 1928 (Mienis, 1977); successively from Egypt (Moazzo, 1939); southern Turkey (Engl, 1995). A punctual record, without follow-up, in Caprolace lagoon, Italy (Bini, 1983).

Locally common.

speculated reasons for success :

Possibly introduced by shipping and then from Port Said to the Suez Canal and to the Eastern Mediterranean (Singer and Mienis, 1991).

Potentially an edible species, also used as bait for angling.


  • Engl W., 1995. Specie prevalentemente lessepsiane attestate lungo le coste Turche. Bollettino Malacologico, 31(1-4): 43-50.
  • Hanafy M.H., 1996. Induction of imposex in the gastropod Thais carinifera from the Suez Canal and the Mediterranean Sea. Journal of the Egyptian German Society of Zoology, 21(D): 135-152.
  • Mienis H.K., 1977. An early record of Thais carinifera from the Mediterranean coast of Israel. Levantina, 7: 70.


  • Mienis H.K., 1994a. The carinated rock-shell Thais lacera (Born, 1778): a Lessepsian migrant in the Mediterranean Sea and an anti-Lessepsian migrant in the Red Sea. Conchologist's Newsletter, 131: 401-405.
  • Moazzo P.G., 1939. Mollusques testacés marins du Canal de Suez. Mémoires de l'Institut d'Egypte, 38: 1-283, pl. 1-14 + frontispice, maps 1-4, Cairo [Thais cariniferus p.163].
  • Singer B.S. and Mienis H.K., 1991. Conchiglie del Mar Rosso. La Famiglia Thaididae (I). La Conchiglia, 260: 16-19.


Last update : January 2005

©ciesm 2002