Strombus

Like almost all shelled gastropods, conches have spirally constructed shells. Again, as is normally the case in many gastropods, this spiral shell growth is usually right-handed, but on very rare occasions it can be left-handed.

True conches have long eye stalks, with colorful ring-marked eyes at the tips. The shell has a long and narrow aperture, and a short siphonal canal, with another indentation near the anterior end called a stromboid notch. This notch is where one of the two eye stalks protrudes from the shell.

The true conch has a foot ending in a pointed, sickle-shaped, operculum, which can be dug into the substrate as part of an unusual "leaping" locomotion.

True conches grow a flared lip on their shells only upon reaching sexual maturity. This is called an alated outer lip or alation.

Conches lay eggs in long strands; the eggs are contained in twisted, gelatinous tubes.^[6] Strombus moves with a leaping motion.^[7]

Strombus shells have a flaring outer lip with a notch near the anterior end called the stromboid notch through which the animal can protrude one of its stalked eyes.^[8]

The phylogenetic relationships among the Strombidae have been mainly accessed in two different occasions, using two distinct methods. In a 2005 monograph, Simone proposed a cladogram (a tree of descent) based on an extensive morphoanatomical analysis of representatives of the Aporrhaidae, Strombidae, Xenophoridae, and Struthiolariidae.^[9] However, according to Simone, only Strombus gracilior, Strombus alatus, and Strombus pugilis, the type species, remained within Strombus. In Simone's cladogram, these three species constituted a distinct group based on at least five synapomorphies (traits that are shared by two or more taxa and their most recent common ancestor). The remaining taxa were previously considered as subgenera, and were elevated to genus level by Simone in the end of his analysis.^[9]

In a different approach, Latiolais and colleagues (2006) proposed another cladogram that attempts to show the phylogenetic relationships of 34 species within the family Strombidae. The authors analysed 31 species in the genus Strombus and three species in the allied genus Lambis. The cladogram was based on DNA sequences of both nuclear histone H3 and mitochondrial cytochrome-c oxidase I (COI) protein-coding gene regions. In this proposed phylogeny, Strombus pugilis, Strombus alatus, Strombus granulatus and Strombus gracilior are closely related and appear to share a common ancestor.^[3]

This genus of sea snails used to comprise about 50 species,^[10] 38 of them occurring in the Indo-Pacific region.^[11] Species within the genus Strombus include:

• Strombus alatus Gmelin, 1791^[12]
• Strombus gracilior Sowerby, 1825
• Strombus pugilis Linnaeus, 1758^[13]
• Strombus fragilis (Röding, 1798)^[14]

Extinct species

Extinct species within this genus include:^[5]

• †Strombus arayaensis Landau and Marques da Silva 2010
• †Strombus bifrons Sowerby 1850
• †Strombus contortus Forbes 1846
• †Strombus coronatus Defrance 1827
• †Strombus cossmanni Dey 1961
• †Strombus daviesi Dey 1961
• †Strombus evergladesensis Petuch 1991
• †Strombus floridanus Mansfield 1930
• †Strombus glaber Martin 1879
• †Strombus herklotsi Martin 1879
• †Strombus inflatus Martin 1879
• †Strombus javanus Martin 1879
• †Strombus junghuhni Martin 1879
• †Strombus labiatus Röding 1798
• †Strombus lindae Petuch 1991
• †Strombus mekranicus Vredenburg 1925
• †Strombus proximus Sowerby 1850
• †Strombus sedanensis Martin 1899
• †Strombus triangulatus Martin 1879
• †Strombus uncatus Forbes 1846
• †Strombus urceus Linnaeus 1758
• †Strombus vomer Röding 1798

Species brought into synonymy

• Conch