Flexopecten hyalinus (Poli, 1795)
Portugal, Mediterranean. Sublittoral to continental slope, usually on sediments. Original taxon: Ostrea hyalina.
Synonyms: flagellatus, pellucidus, pulcherrimus
In nets, Jerba island, Gulf of Gabès, Tunisia. 18mm.
Pecten hyalinus in J. G. Hidalgo: Moluscos marinos de España, Portugal y las Baleares, Madrid 1870, via BHL.
« Testae characteres – Concha rotundata, transversim divaricata, depressa, tenuissima, aequivalvis, nitida; radiis circiter decem latiusculis, explanatis, obsoletis; auriculis subaequalibus, cardine recto. Testae descriptio – Concha prope rotunda, in transversum paullo divaricata, valde depressa, aequivalvis, ac aequilatera, ultra modum tenuis, atque diaphana instar vitri, nitidissima. Valvae glabrae radiis circiter denis decorantur ita depressis, ut nonnisi adverso lumine percipiantur. Intus pariter radiata, radiorum marginibus elatis. Ambitus exterior crenis exilissimis dissectus adparet. Concha flava, saepe albida, maculis rufis sparsim distincta. » – Ostrea hyalina in G. S. Poli: Testacea utriusque siciliae…, vol. II p.159 via BHL.

Comparison with a young Flexopecten glaber (Linnaeus, 1758) from the same spot: details of Ctelonium.
At left hyalinus, at right glaber.
The small size and weighing of its shell allows this species to live on unexpected subtrates, such as this leaf of Posidonia oceanica. Îlot de la Gabinière, off the southern coast of Port-Cros Island, Hyères, Var, S. France. Original picture provided by slebris for iNaturalist – (CC BY-NC).
Another specimen on a leaf, Samena cove, south of Marseille, Provence, S. France. Original picture provided by slebris for iNaturalist – (CC BY-NC).
The ctelonium in an uncommonly coloured specimen from 30-44m deep, San Ġiljan, southeastern Region, Malta. 20,4mm. Original pictures provided by A. Nappo (IT).
(CC BY-NC-SA)
The pattern and the microsculpture in a specimen from Posidonia meadows, Sustjepan shore, uvala Luka Cavtat, S. Croatia. Scale bar: 1mm.
Beached, Omiš, Split-Dalmatia Comitat, S. Croatia. 24mm. Original picture provided by N. Lete (HR).
(CC BY-NC-SA)
S. Croatia. 24mm.
— back to Pectinidae —