Amphora maletractata var. constricta (Heiden) Simonsen (1992: 72)

Al-Handal, Adil Y., Thomas, Evan W. & Pennesi, Chiara, 2018, Marine benthic diatoms in the newly discovered coral reefs, off Basra coast, Southern Iraq, Phytotaxa 372 (2), pp. 111-152 : 136

Amphora maletractata var. constricta (Heiden) Simonsen (1992: 72) ( Figs 79, 80 )

References: Simonsen 1992, p. 71, pl. 76, figs 7–15; Witkowski et al. 2000, p.144, pl. 167, figs 12–16.

Features: Length: 40–58 μm, width 7–10 μm, striae 18–20 in 10 μm on the dorsal side.

Description: Valves dorsiventral, semi-elliptic with protracted capitate apices. Dorsal margin arched, slightly constricted in the middle, ventral margin straight. Dorsal striae interrupted by lanceolate hyaline area on the dorsal margin. Axial area narrow, slightly widens laterally in the center, central area small, rectangular. Raphe straight.

Remarks: This taxon can be easily identified by the wide hyaline area separating striae bands on the dorsal margin. This variety differs from the type by having a small constriction in the dorsal margin opposite to central area.

Ecology and Distribution: Marine to brackish water form. Although recorded from variable geographic locations including the Arctic ( Witkowski et al. 2000), this taxon was not reported to be common on marine coasts. Not recorded previously from the Gulf. Rare in Basra corals.

Figures

FIGURES 75–90. Marine benthic diatoms in coral reefs off Basra. Figs 75, 76. Amphora grevilleana, Figs 77, 78. Amphora janischii, Figs 79, 80. Amphora maletracta var. constricta, Fig. 81. Amphora marina, Fig. 82. Amphora mexicana, Figs 83, 84. Amphora ocellata, Figs 85,86. Tetramphora ostrearia, Figs 87,88. Tetramphora rhombica, Fig. 89. Amphora spectabilis, Fig. 90. Amphora sp.