Trochus Linnaeus 1758

Trochus is a genus of medium-to large-sized, top-shaped sea snails with an operculum, of the family Trochidae, the top snails.^[1]

When the word "trochus" or "Trochus" is used in reference to fishing sea snails for commercial purposes, the usual species targeted is Tectus niloticus, which is valued for its nacre or mother of pearl layer, which was traditionally made into items such as pearl buttons and jewelry. Tectus niloticus is no longer classified as a Trochus species, and it is no longer classified in the family Trochidae; it is now placed in the family Tegulidae.

History

The name Trochus, according to P. Fischer^[2] was used for the first time by Guillaume Rondelet, in 1558, who assembled under this title a rather miscellaneous assortment of univalves. Linnaeus' genus Trochus is composed principally of true Trochidae, but it is now viewed as having contained species of several other very different families.

Lamarck further restricted the group, by eliminating several genera; and in the 19th century the labors of Gray, H. Adams and A. Adams and others, contributed towards a more systematic arrangement of the family.^[3] Further revisions have narrowed down the number of species in this genus, and most names have become synonyms.

Shell description

Sea snails in the genus Trochus have large, thick, solid shells that have a broadly conical spire and a flat to convex base. The periphery is angulated. The outer and basal lips are smooth within. The columella has a strong fold above, ending in an obtuse tooth below.^[3]

The interior of the shell is pearly and iridescent because of a thick layer of nacre (mother of pearl).

Species

Species within the genus Trochus include:^[1]

• † Trochus antipodum Wilckens, 1922
• Trochus calcaratus Souverbie in Souverbie & Montrouzier, 1875
• Trochus californicus (A. Adams, 1853)
• Trochus camelophorus Webster, 1906
• Trochus cariniferus Reeve, 1842
• Trochus chloromphalus (A. Adams, 1851)
• Trochus concinnus Philippi, 1846
• Trochus cumingii A. Adams, 1853
• Trochus elegantulus W. Wood, 1828
• Trochus erithreus Brocchi, 1821
• Trochus fastigiatus A. Adams, 1853
• Trochus ferreirai Bozzetti, 1996
• Trochus firmus Philippi, 1849
• Trochus flammulatus Lamarck, 1822
• Trochus fultoni Melvill, 1898
• Trochus histrio Reeve, 1848
• Trochus intextus Kiener, 1850
• Trochus kochii Philippi, 1844
• Trochus kotschyi Philippi, 1849
• Trochus laciniatus Reeve, 1861
• Trochus maculatus Linnaeus, 1758
• Trochus nigropunctatus Reeve, 1861
• Trochus noduliferus Lamarck, 1822
• Trochus obesus Reeve, 1861
• Trochus ochroleucus Gmelin, 1791
• Trochus radiatus Gmelin, 1791
• Trochus rota Dunker, 1860
• Trochus sacellum Philippi, 1855
• Trochus squarrosus Lamarck, 1822
• Trochus stellatus Gmelin, 1791
• † Trochus subanceps Sinzow, 1897
• Trochus subincarnatus P. Fisher, 1879
• Trochus submorum (Abrard, 1942)
• Trochus tentorium Gmelin, 1791
• Trochus tubiferus Kiener, 1850
• Trochus venetus Reeve, 1862
• Trochus zhangi Dong, 2002

Synonyms

The following species are nomina dubia (names of unknown or doubtful application)

^[1]

• Trochus bicinctus Philippi, 1849
• Trochus quadricinctus Mühlfeld, 1824

Species inquirenda

^[1]

• Trochus artensis P. Fischer, 1878
• Trochus fabrei Montrouzier in Fischer, 1878
• Trochus incarnatus Philippi, 1846
• Trochus pulchellus Philippi, 1846
• Trochus reevei Montrouzier in Souverbie & Montrouzier, 1866
• Trochus rhodomphalus Souverbie in Souverbie & Montrouzier, 1875
• Trochus saga Philippi, 1846
• Trochus scrobiculatus Souverbie in Souverbie & Montrouzier, 1866
• Trochus sublaevis Geinitz, 1842
• Trochus subviridis Philippi, 1848

References

• A. Adams, Contributions toward a Monograph of the Trochidae, in Proc. Zool. Soc, 1851, pp. 150–192.
• R- A. Philippi, Monograph of Trochus in Syst. Conchylien Cabinet, ed. 2 (1846 to about 1856).
• Lovell Reeve, In Conchologia Iconica vol. xiii. (1861) (a very incomplete work)
• Herbert G.G. (1993). Revision of the Trochinae, tribe Trochini (Gastropoda: Trochidae) of southern Africa. Annals of the natal Museum 34(2):239-308.
• Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca, in: Costello, M.J. et al. (Ed.) (2001). European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification. Collection Patrimoines Naturels, 50: pp. 180–213