Gymnodinium quadrilobatum
Diagnosis
Cellula mobilis, forrna Gymnodinii, quasi rectangularis vel rotundata, dorsiventraliter compIanata, 21,6-29,4 μm longa, I9,6-25,5 μm lata, 13,7-21,6 μm crassa; sulcus angustus, antapicem attingens; chloroplasti aureo-brunnei, circ. 20 ad 30, disciformes, loriformes vel ellipsoidei, peripherici; nucleus dinokaryoticus et nucleus eukaryoticus praesentes; stigma conspicuum, posticum. Cellula immobills, sessilis, forma folii Trifolii quadrifoliolati; paries crassus; pagina cellulae laevis; reproductio asexuatis per cellulas mobiles ortas per bipartitionem protoplasti. Flagellatum marinum, arenicolum.
Etymology
The epithet quadrilobatum describes the characteristic four-lobed shape of the non-motile form.
Ecology
Sand layer in tidal pools.
Life cycle
The reproductive cycle of the organism consists of a motile and non-motile phase. The nonmotile cell undergoes cell division and produces two motile cells. These motile cells are released at the onset of the light period. After several hours of swimming, the motile cell is directly transformed into the non-motile form by shedding its flagella. The newly developed non-motile form is devoid of a cell wall, but a thick wall is formed within 24 h. During this stage, the cell develops its distinctive shape . The nonmotile stage is regarded as a division stage and not a zygotic stage.
Original description
Reference(s)
Observation site(s)
SYMBIONTS
Association with... | Region origin | Name of site | In reference... |
---|---|---|---|
Nitzschia sp. | (2004) |