Snow algae and their relevance to astrobiology

Jana Kvíderová

Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic

&

Institute of Botany, Academy of Sciences of the Czech Republic, Třeboň, Czech Republic

Snow algae

- Algae growing in melting snow- „Watermelon snow“ = dense communities of

snow algae- Alpine and polar regions- Temporary and perrenial snowfields

Red (left) and green (right) snow. Krkonoše Mts. Czech Republic.

Snow algae

Dust- and soil-covered snowfields in Svalbard

- glaciers and snowfields

Snow algae

- Unicellular or filamentous microorganisms - Chlamydomonas sp. - Chloromonas sp.- Raphidonema nivale…

- Complex life cycles - Motile (flagellates) and

non-motile (cysts) stages- Chlamydomonas sp. and

Chloromonas sp.

Examples of snow algae species and genera: A - Chlamynomonas nivalisB - Chloromonas nivalisC - Chloromonas brevispinaD - Chloromonas rosaeE - Cryocystis sp.

A

B C

D

E

Life cycles

Modified from Hoham et Duval (2001) in Snow ecology

Svalbard snow algae

The species and genera of snow algae found in Petuniabukta samples (Kvíderová (2012) Czech Polar Reports). The number indicates the size of the scale in µm A-F – zygospores of Chlamydomonas cf. nivalis, G – newly formed zygospore of cf. Chloromonas nivalis, H-I – cf. Cryodactylon glaciale (? Chlamydomonas brevispina), J-K – zygospores of Chlamydomonas sp., L – cf. Chlainomonas sp.

Environment of snow algae I.

- Low stable temperature- Freeze-thaw cycles- High and variable radiation (VIS and UV)

Variability of environmental conditions in snow (Kvíderová (2010) Arct Antarct Alp Res)Abbreviations: PAR - photosynthetically active radiation; Tair - air temperature; Tsnow - snow temperature; UVR - UV radiation

Environment of snow algae II.

- Variable nutrient availability- Short vegetation period

Snow nutrient concentrations and their relations to occurence of snow algae (Kvíderová et Kociánová (2011) Opera Corcontica)

Abbreviations: Alk - alkalinity; Alt - altitude; Cond - conductivity; DRP - dissolved reactive phosphorus; NH4-N - ammonium nitrogen; NO3-N - nitrate nitrogen; N:Pin - inorganic N:P molar ratio; N:Ptot - total N:P molar ratio; Ntotal - total nitrogen; pH - snow pH; Ptotal - total phosphorus. CbreC - cysts of Chlr. brevispina; CnivC - cysts of Chlr. nivalis; CnivZ - zoospores of Chlr. nivalis; CrosC - cysts of Chlr. rosae.

Ecophysiological requirements I.

Temperature and irradiance growth requirements of Chlamydomonas sp. strain Ľadové originating from the High Tatra Mts., Slovakia

Ecophysiological requirements II.

- Psychrophilic and psychrotolerant species

- Tolerance of broad irradiance range

Growth of Chlamydomonas sp. strain Ľadové in gradient of temperature (left) and irradiance (right)