Fig 5.

(A) Newly formed cyanobacterial enrichment cones 4 weeks after medium flooding. (B) Older cones 6.5 months after flooding. The matured structures become more similar to the structures found at Octopus Spring. (C) Cones grown in medium that was flooded upon inoculation instead of after formation of the mat on the agar surface, 3 months postinoculation. (D) An aggregate that has landed on the mat appears to be lifted up. (E) Cones formed on agar incubated at a 34° angle from horizontal. The arrow indicates the direction of light. “X” indicates the angle of cone inclination from the surface. Scale bars are approximate and are based on external flask markings. Potential magnification due to the liquid medium is not accounted for.