Akinetes are long or short cylindrical with rounded ends or elliptical, adjacent to heterocytes or distant.
Heterocystscylindric, intercalary, 5-7 [micro]m in diameter and 7-20 [micro]m long, akinetes elongate, cylindric, solitary formed near the middle of the trichome but not adjacent to the heterocyst, 6-8 [micro]m in diameter and 20-60 [micro]m long (Fig.
Measurement and standard deviation of length and width pattern of vegative cells, heterocytes and akinetes, were calculated using a Microsoft Excel program (Microsoft Office 2007) in four conditions tested and graphs produced using the Bioestat 5.0 program (Ayres et al., 2005).
Akinetes were found between the median portion of the trichome and its extremity, closer to the heterocyst, with one to four akinetes per individual.
Production of akinetes only occurred under some conditions.
Some algae grow from resting stages, called akinetes
, that lie in bottom sediments.
Mature trichomes also contain spores called akinetes. According to Peters (1975), trichomes, on average, consist of 60.9% vegetative cells, 23.1% heterocysts, and 16% akinetes.
The originally undifferentiated filaments become entrapped in a cup-shaped indusium which triggers their differentiation into akinetes. The symbiosis is reestablished following gametogenesis and embryogenesis (Peters & Perkins, 1993).
Approximately 10 Anabaena species were identified in the fresh material; however, establishing the dominant species when counting was difficult, as frequently only pieces of filaments without akinetes
and heterocysts were found in the counting chamber.
raciborskii trichomes had heterocytes (41.97%) and few had akinetes