Science Report
2/13/15
Paul Bakken
Site 182 (12S 0518586 UTH 4250502 ELEV 1363 m)
A new lichen colony field was found at a site about 400-500 m east of the hab, during the morning EVA, i.e., 13022015-EVA-Crew149-EVA-5. The colony field was close to another colony field that was found during the yesterday’s geological EVA (by Bakken, Nicoletatos and Gerardi), but greater than it, though we couldn’t locate the yesterday’s site.
Today’s site hosted a lot of patches of lichen colonies consisting of five “chromotypes” colouring orange, green, yellow, grey and black. The patches were distributed on surfaces of whitish sandrocks in an area of about 5 m x 5 m.
Lichen specimens were collected by scraping from the rock surfaces as we did the day before yesterday (11 Feb). These specimens were to be used for microscopic observations and cultivation trails.
By preliminary microscopy of lichen tissue, we observed the cells arranged distinctly in two manners (maybe or more). The outermost cells were rod-shaped and arranged in a single layer, in a closed finger-like manner. These cells are regarded as fungal “cortex” (or “epithecium”) and serve to protect interior algal partner from excessive UV and desiccation. Interior (or “hypothecium”) cells, regarded as algal, were round to square-shaped and arranged in a criss-cross manner. These cell arrangements are typical of “crustose” lichens, as depicted in most textbooks (for example, page 9 of “How to Know the Lichens, Second Edition” by Mason E. Hale, 1979).
Additional lichen specimens were collected not by scraping, but by peeling off the colonized surfaces of host rocks, because a-few-mm-thick pieces of the rock surfaces were easily peeled. By doing so, lichens and nearby microflorae (of the rock pieces) were simultaneously collected, and therefore we did not have to collect nearby soil samples for analysing “ambient” or “background” microflorae. These specimens will be used for genotypic characterizations.