Stream macroalgae of Hawai`i: an identification guide - Hawaii.gov
Stream macroalgae of Hawai`i: an identification guide - Hawaii.gov
Stream macroalgae of Hawai`i: an identification guide - Hawaii.gov
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Scytonema<br />
Classification: Cy<strong>an</strong>obacteria (Family<br />
Scytonemataceae)<br />
General habit: a falsely br<strong>an</strong>ched cy<strong>an</strong>obacterium<br />
that forms thick mats or tufts th<strong>an</strong> c<strong>an</strong> be<br />
abund<strong>an</strong>t in streams, <strong>of</strong>ten yellowish-brown in color<br />
from pigmentation, most commonly attached to rock<br />
surfaces<br />
Species in Hawai‘i: S. arch<strong>an</strong>gelii, S. chiastum, S.<br />
coactile, S. crispum, S. figuratum, S. fritchii, S.<br />
guy<strong>an</strong>ese, S. h<strong>of</strong>m<strong>an</strong>nii, S. myochrous, S. ocellatum,<br />
S. rivulare, S. stuposum, S. tolypothricoides, S.<br />
varium, Scytonema sp.<br />
Isl<strong>an</strong>d distribution: Kaua‘i, O‘ahu, Maui, Hawai‘i<br />
Distinguishing features: false br<strong>an</strong>ches normally<br />
occur in pairs in this genus (Figs B, D, E), only a<br />
single filament is contained within the surrounding<br />
sheath, sheath c<strong>an</strong> be thick <strong>an</strong>d layered in<br />
appear<strong>an</strong>ce <strong>an</strong>d <strong>of</strong>ten highly pigmented in <strong>Hawaii</strong><strong>an</strong><br />
specimens<br />
Compare with: Dichothrix, Tolypothrix<br />
21<br />
A. A tuft <strong>of</strong> Scytonema as viewed under a dissecting<br />
microscope. Scale bar = 1cm. B. Filament <strong>of</strong><br />
Scytonema under a compound microscope illustrating<br />
double false br<strong>an</strong>ching. Scale bar = 25µm.<br />
C. A heterocyst <strong>of</strong> Scytonema. Scale bar = 25µm.<br />
D, E. Double false br<strong>an</strong>ching <strong>of</strong> Scytonema filaments.<br />
Scale bar = 25µm (D), 30µm (E).