A. granulata var. angustissima is a filamentous centric diatom, representing a slender variation of the more prevalent A. granulata type. In this variant, the cells are typically smaller, measuring less than 5 μm in diameter, whereas the standard A. granulata ranges from 9 to 16 μm in diameter. It’s worth noting that A. granulata var. angustissima is quite scarce in Lake Kinneret. Another distinguishing characteristic of this variety is the almost imperceptible points on its valves. This reduced size and subtle valve ornamentation set it apart from its more common counterpart.