Copromyxa vandevyveri Van Wichelen & Vanormelingen, 2016

Van Wichelen, Jeroen, D’Hondt, Sofie, Claeys, Myriam, Vyverman, Wim, Berney, Cédric, Bass, David & Vanormelingen, Pieter, 2016, A Hotspot of Amoebae Diversity: 8 New Naked Amoebae Associated with the Planktonic Bloom-forming Cyanobacterium Microcystis, Acta Protozoologica 55 (2), pp. 61-87 : 82

Copromyxa vandevyveri Van Wichelen & Vanormelingen sp. n.

Diagnosis: Locomotive amoebae limax-shaped, 20–55 µm long and 8–25 µm wide, displaying anteriorly a well pronounced hyaline cap. Bipodial and multipodial movement common by means of alternating sprouting (eruptive) lobes. Pseudopodia often displaying a few small, sprouting, short-lived subpseudopodia laterally. Occasionally a few adhesive uroidal filaments present. Vesicular nucleus 4–8 µm long and 4–7 µm wide with one centrally to slightly eccentrically located globular nucleolus. Usually one contractile vacuole posteriorly. Cytoplasm contains up to 20 small crystals. Floating forms spherical to irregular, about 15–20 µm in diameter with radially up to 12 small hyaline lobes. Spherical cyst occasionally present.

Feeding behavior: Grazing on Microcystis cells was observed in the Microcystis bloom sample and in laboratory cultures.

Type material: Strain A 5 DVDPB is available from the NIES Microbial Culture Collection (NIES-3724). The 18S rDNA GenBank accession number is KP719189 .

Type locality: Isolated from a Microcystis bloom sample from a fish pond ( Drie Vijvers ) in De Panne ( Belgium) ( Table 1 ) .

Etymology: vandevyveri referring to the first author’s beloved wife Evelien Van de Vyver but also refers to the habitat this amoeba occupies since in Dutch ‘van de vijver’ literally means ‘from the lake’.

Differential diagnosis: Morphologically, C. vandevyveri differs slightly from C. microcystidis by its less eruptive-like pseudopodium formation, its longer, slender subpseudopodia during non-oriented movement (max. 25 µm long compared to 13 µm in C. microcystidis ) and the absence of large crystals in the cytoplasm. Also its 18S rDNA sequence is clearly different from that of C. microcystidis .