Stygiellidae
From Wikipedia, the free encyclopedia
| Stygiellidae | |
|---|---|
 | |
| Stygiella incarcerata under light microscopy stained with protargol | |
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| Velundella nauta under DIC microscopy | |
Scientific classification  | |
| Domain: | Eukaryota |
| Clade: | Discoba |
| Class: | Jakobea |
| Order: | Jakobida |
| Suborder: | Andalucina |
| Family: | Stygiellidae Pánek, Táborský & Čepička 2015[1] |
| Type genus | |
| Stygiella Pánek, Táborský & Čepička 2015 | |
| Genera[1] | |
| Diversity | |
| 6 species | |
 | |
| Stygiellidae distribution map.[1] | |
Stygiellidae is a family of free-living marine flagellates belonging to the order Jakobida, a deep-branching lineage within the eukaryotic supergroup Discoba. They are unicellular organisms that commonly inhabit anoxic, sulfide-rich and ammonium-rich marine habitats worldwide.[1]
Members of Stygiellidae are genetically diverse but morphologically similar anaerobic jakobids. The unifying aspect of their appearance is their cristae-lacking mitochondria due to the secondary loss of aerobic metabolism. They resemble jakobid cells, and form two morphotypes: grooved cells, attached to the substrate, with a conspicuous groove; and swimming cells, with a less distinct, narrower groove. Both morphotypes move in a spiral motion, although the swimming cells are faster. It is difficult to distinguish morphological aspects between species due to the variability among cells within the same strain and the similarity between grooved and swimming cells.[1]
Ecology and distribution
Stygiellidae are bacterivorous nanoflagellates almost exclusively found in marine, oxygen-poor (anoxic or microoxic) environments, often in presence of sulfides, methane or ammonium. However, some environmental sequences of Stygiellidae have been reported in oxic waters in Saanich Inlet, without sulfide or ammonium. They are also detected in other non-marine saline environments such as brackish waters and inland salt springs, but never in freshwater habitats.[1]