Salut Päule,
J'y vois une Amphora rhombica Kitton.
Je ne sais pas ce qui différencie les deux espèces par contre.
Mais le nom A. securicula n'est pas répertorié dans AlgaeBase, s'agit-il de synonymes ?
Voilà la description du guide des diatomées du Koweït :
Amphora rhombica Kitton 1876 var. intermedia Cleve 1895
Plate 141: a-g
References:
Peragallo & Peragallo, 1897-1908: Pl. L: 3, 4
Ricard, 1977: Pl. 6: 18, 19
Foged, 1984: Pl. LIII: 1-3
Podzorski & Håkansson, 1987: p. 51, Pl. 16: 3
Ricard, 1987: fig. 924
Witkowski et al., 2000: p. 149, Pl. 168: 12, 13
Al-Kandari et al., 2009: p. 112, Pl. 65: B
Frustules broadly lanceolate with truncate ends. Valves semi-lanceolate with convex dorsal margin, straight
ventral margin and acute apices, 73-94 μm long, 12-16 μm broad. Raphe biarcuated, eccentric, lying
closer to ventral margin. Axial area very narrow, central area absent. Dorsal transapical striae composed
of elongated areolae arranged in radiate rows, 13.5-15 in 10 μm, crossed by undulating longitudinal ribs.
Ventral striae short, parallel, 13-14 in 10 μm. Single large golden-brown deeply lobed chloroplast lies
along dorsal side of cell.
Distribution: Marine species widespread on coasts. It has been previously reported from bottom sediments
in Shatt Al-Arab estuary, Iraq (Al-Handal, 2009); and from Kuwait’s coastal waters (Al-Kandari et al., 2009).
Occurrence: Epipelic form. Sporadically observed in Kuwait’s intertidal sandflats.
