Popis
Autor: Jan Delsing
Text ID: 111043
Text Type: 1
Page: 0
Založeno: 29.08.2021 23:54:40 - Uživatel Delsing Jan
Language: EN
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Habitat: it lives on rocky bottoms in the circalittoral zone but also in the deep infralittoral zone, rarely in remarkable depths, often connected with Cerianthus membranaceus presence.
Distribution: it can be found all over the Mediterranean where it is common relatively.
Imaged shells: the three largest imaged shells are coming from Scilla (Reggio Calabria - Calabria - Italy), at 40 m depth, the two smallest ones from rubble samples collected in Pantelleria Is, (Sicily - Italy), at 50 m depth. Notes: shell solid, slim in form, biconic in outline, whorls convex, siphonal canal long and straight,
umbilical aperture clear. Quite changeable sculpture made by 8-10 axial ribs and by numerous spiral belts with different solidity, covered with lamellae foliaceous imbricated with different solidity, them too. Sometimes either the second or the third spiral belt is thicker making one slight carina. Roundish in aperture, margin of external lip incised in correspondence with the spiral cords. Protoconch, light yellow in colour, made by 3.5 whorls of spiral, about one whorl of which forms the nucleus covered with small granules. The following whorls are crossed by two evident spiral carinae and by one axial streaking. White greyish in colour pattern, sometimes rosy as far as the fresh specimens are concerned. Operculum yellowish in colour, while the animal is white. Due to its lamellous sculpture and to its outline, it is easily distinguishable from its similar ones even during its juvenile stage. Settepassi (1977) described numerous varieties in form, so to prove its remarkable intraspecific variability.
This species had a complex taxonomic story, since the several taxa: alucoides, lamellosa, squamulosa and other ones could not be used, until Bouchet and Waren (1985) considered as valid the present name designating a neotype. The adult specimens average measures are around 30-35 mm in height.
Scaperrotta, M. ,Bartolini, S. & Bogi, C., 2009. Accrescimenti, Vol. 2. Stages of growth of marine molluscs of the Mediterranean Sea.