Lake Pavin History, geology, biogeochemistry, and sedimentology of a deep meromictic maar lake

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STAGE 1: ENCYSTMENT

STAGE 2: PROSPORANGIUM

STAGE 3: EXPANSION

STAGE 4: BUDDING

STAGE 5: MATURE STAGE

STAGE 6: EMPTY STAGE

Attachment of zoospores on host cell

R.crassum: outgrowths expanded

through several cells as a tubular

rhizoid from the prosporangium

R.akinetum: P rosporangium

development inside akinete

Discharges of

zoospore content

into the host cell

Apparition of prosporangium (P)

Emergence of an epiphytic bud of

sporangium

Mature sporangia surmounted by a

papilla (pa)

Empty phase

Maturation phase

Young phase

Dehiscence of papilla and release

of zoospores

Maturation of

sporangia and

zoospore production

via assexual

reproduction

Rhizosiphon crassum Rhizosiphon akinetum

Fig. 20.4 The six different life stages of the two chytrid species,
Rhizosiphon crassum ( A ) and Rhizosiphon akinetum ( B ) parasitizing
the cyanobacterium Anabaena macrospora from the productive Lake
Aydat: Stage1: Encystment; Stage 2: Prosporangium; Stage 3:
Expansion stage; Stage 4: Budding; Stage 5: Mature stage; Stage 6:

Empty stage. The six life stages were grouped into three different

phases: Young phase (Stages 1 and 2), Maturation phase (Stages 3, 4

and 5) and Empty phase (Stage 6). Prosporangium (P) and Papilla (Pa).

For more details, see the main text and Gerphagnon et al. ( 2013b )

T. Sime-Ngando et al.