Limnognathia maerski

Limnognathia maerski is a microscopic freshwater animal and one of the two known species of Limnognathia, the only genus in the phylum Micrognathozoa, a name meaning small-jawed animal. The genus was first found on Disko Island, Greenland, in 1994, and L. maerski was described in 2000 by Kristensen and Funch from Greenland and Spain, while a second species, Limnognathia desmeti, was described in 2025 from the Crozet Islands. The two species have no recognizable morphological differences but genetic studies show them to be distinct. The animal feeds mainly on bacteria, blue-green algae and diatoms, using complex jaws of fifteen separate elements, each between 4 and 14 micrometres, which it can extend partly outside its mouth. Every specimen collected so far has had female organs. It lays thin-walled eggs that hatch quickly and thick-walled eggs believed to survive freezing over winter. Its closest relatives are the rotifers and the gnathostomulids, which together form the Gnathifera.