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Leptomyxa
Leptomyxa valladaresi, a) Trophozoites in multi-pseudopod locomotion b) Trophozoite in limax locomotory formwith the contractile vacuole (cv) toward the rear. d) Bipolar formwith two leading pseudopods. c) Three cysts with one nucleus (left most cyst), two nuclei (middle) and three nuclei (right most cyst) – from Del Valle et al. 2017

Leptomyxa valladaresi Del Valle et al. 2017

Diagnose: The amoeba adopts two main locomotory morphologies. It is transiently limax with a long, simple, tubular shape where the length is 70-180 µm; breadth adhesive 20-60 µm only occasionally does this form have an uroidal filaments or villous bulbous uroid. In limax locomotion the frontal hyaline cap occupies up to 1/5 of the total length of locomotive cell. The more usual locomotory habit is a flattened multi pseudopodal form and this form may have adhesive uroidal filaments and/or villous bulbous uroid but these are not as prominent a feature compared to reports for other leptomyxids. The amoeba is predominantly uninucleate but larger individuals may (rarely) have as many as 4 nuclei in old cultures. Nuclei are spherical 9 µm in diameter (range 6-11 µm). but can become oval shaped as they a compressed within a thinner part of the cell. The cyst (19-28 µm in diameter) is again usually uninucleate and is apparently single walled by light microscopy. The cysts can be stored cryogenically in the usual manner. There are no pores visible in the wall by light microscopy.

Ecology: A dry gully in a large forested area consisting of the Canary Island Pine (Pinus canariensis) from a site known as “Las Lajas” (the rocks) on the southern flank of Mount Teide, Tenerife, Canary Islands, Spain.

Remarks: Resembles L. variabilis in size and morphology, but L. variabilis is multicellular whereas L. valladaresi is predominantly mononucleate. It also resembles L. australiensis in size and organization of the locomotive form, and in the general size of the cyst (L. valladaresi being slightly smaller). In common with most Leptomyxid amoebae (Smirnov et al., 2017), a firm identification of L. valladaresi is only possible by sequencing the 18S gene.

Leptomyxa
Leptomyxa fragilis, amoebae were fixed with Nissenbaum’s fixative and the nuclei (n) were stained with Kernechtrot nuclear fast red. The uroidal filaments (uf) are also seen here – after Del Valle et al. 2017
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