Alvania lineata Risso, 1826
Mediterranean.
Grazer and detritus feeder in infralittoral gardens.
Synonyms: capuleti Oberling, costulosa and nodulosa Risso.
10cm deep,Vlaška Bay, Brač island, Split-Dalmatia Comitat, S. Croatia. 4mm. Original picture provided by R. Stanić (HR).
(CC BY-NC-SA)
3-5m deep, in hollows among the wide Posidonia meadow of the Anse des Fossettes, at the root of the eastern peninsula, Saint-Jean-Cap-Ferrat, Alpes-Maritimes, SE. France. 4,7-5mm.
Les Fossettes, Saint-Jean-Cap-Ferrat. 4,2mm.
Protoconch granulose: randomly on the egg-shell, spirally on the following whorl.
« Testa opaca, glabra ; anfractibus 6 (apicalibus duobus mamillalis) transversim costatis, costis et lineis longitudinalibus elevatis, aequalibus sculptis ; epidermide albido flavescente, purpureo rubescente decussatim striata. » – A. Risso: Histoire naturelle des principales productions de l’Europe Méridionale… vol. IV, Paris 1826, via BHL.
 
At right: 3 specimens (smaller) from 12m deep, Scilla, Reggio Calabria, SW. Italy. 2-2,75mm. Left: this cream specimen has its spiral cords appearing only anteriorly to the periphery, while they run usually along the whole whorl. Same spot. 3,5mm.
Same spot. 3,3-3,5mm.
7m deep, Vouliagmeni area, Attikí, SE. Greece. 4,7mm.
Protoconch smoothed…
Above and below: 8m deep, Vouliagmeni area. 4,8mm.
The protoconch, unfortunately damaged, is not multispiral as in A. discors. This may be an unusual lineata, despite the small number of radial costae.
Risso: « The colour of this shell is yellowish, striped with a purple-red array; six whorls (the two of the summit mamillated) transversely costulated, with longitudinally arranged furrows and striae of equal elevation. In coralligen. »
 
There are 3 (often) to 5 (sometimes) marked spiral ribs on the base, including the sutural one. Above: possible lineata from 25-30m deep, Le Dramont, east of Saint-Raphaël, Var, SE. France. 3,6mm.
8m deep, Bozcaada island, Çanakkale province, W. Marmara, NW. Turkey. 3,9mm.
36m deep, San Giovanni Li Cuti, Catania, E. Sicily. 3,6mm.
Cap Ras, Llançà, Girona, Catalunya, NE. Spain. 4mm.
35m deep, Cristo del Circeo, Lazio, W. Italy. 3,5mm.
8m deep, Bozcaada. 2,66mm.
Alvania aeoliae Palazzi, 1988. Western Italy to Malta.
 
The shell is somewhat similar to other forms but with a difference: the combination of weak nodules, thin spiral ribs and the pale band that covers the two rows at the periphery like in discors. As intergrades do exist between aeoliae and lineata, the validity of this species must be strongly questioned.

Above and below:
35m deep, Cristo del Circeo. 2,7mm.
Protoconch of about 1,5 whorls, like in usual lineata. « The basal axial sculpture seems to be an extremely variable character, with several intermediate stages linking shells with most prominent cords to ones lacking them altogether, a spectrum remarkably demonstrated in Maltese material. » – Nappo, Cilia & Cardona: “Additions to the marine mollusc fauna of the Maltese Archipelago…”, Bollettino Malacologico vol. 60, Milano 2024, p.55.

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