Turbo marmoratus Linnaeus, 1758 is the type species of the Turbo subgenus Lunatica Röding, 1798.
The subgenus is entirely Indo-West Pacific in distribution and consists of 3 extant species:
All three species are found subtidally, the first two in association with reefs.
T. marmoratus and T. imperialis, collectively known as 'the green snail', have been the focus of an intense fishery over the last century and both continue to be fished for their nacreous shell.
There is no genetic evidence for cryptic species in this subgenus based on the limited data available, but the three species are regularly confused. However, as well as differing in shell characteristics and distribution, they can be distinguished by their opercula:
Opercula of A. Turbo (Lunatica) marmoratus; B. Turbo (Lunatica) imperialis; C. Turbo (Lunatica) militaris.
These are species that resemble one another so closely that they have traditionally been considered a single species. In some cases close scrutiny of their morphology enables them to be distinguished, in other cases this is only possible by genetic analysis.
Living, still in existence (as opposed to 'extinct').
Consisting of nacre - an iridescent material composed of aragonite (a form of calcium carbonate). Nacre is also known as mother of pearl.
A hard plate that serves to close the mouth when the animal is withdrawn into the shell.