Mallomonas temonis Nĕmcová, 2013

Němcová, Yvonne & Kreidlová, Jana, 2013, Two new species of Mallomonas (Chrysophyceae: Synurales): Mallomonas temonis and Mallomonas divida, Phytotaxa 87 (1), pp. 11-18 : 12-14

Mallomonas temonis Nĕmcová sp. nov. ( Figs 1A–L)

Type:— SOUTH AFRICA. Western Cape: unnamed small pool at Table Mountain , 33° 57.499´S, 18° 24.282´E, 1064 m a.s.l., sample collected by Y. Nĕmcová, 20 August 2010. Figure 1D .

Three types of scale may be discerned including apical, body, and rear scales; however, a continuous transition between body and rear scales exists. Apical scales (2.6 – 3.2 × 1.9 – 2.5 µm) are broad and remarkably asymmetric, with one lateral edge shorter than the other. A large, broad, flat dome is eccentrically situated and its posterior part is extended, which forms a lip. The base plate is marked with closely spaced pores, which are clearly visible on the less silicified scale ( Fig. 1I). A scale is surrounded by a submarginal rib curving toward the dome. At the posterior part of the scale, a strong, more or less transversal rib connects the lateral parts of the submarginal rib. A secondary reticulum of smaller meshes with more delicate ribs may be developed under the transversal rib ( Fig. 1A). The submarginal areas possess struts (occasionally bifurcated) radiating from the submarginal rib; the struts do not reach the proximal border. The proximal border surrounds approximately half of the scale outline ( Figs 1A–B). Body scales (3.2 – 3.9 × 2.1 – 2.7 µm) are oval and essentially bilaterally symmetrical ( Figs 1C–D). The submarginal rib fuses with the dome forming the continuous entity ( Figs 1H, 1L). The strong transversal rib crosses the shield in approximately the lower half to third ( Figs 1K–L). Remnants of the reticulum of smaller meshes are sometimes visible on the shield ( Fig. 1G). Rear scales (2.1 – 2.7 × 1.4 – 1.9 µm) are smaller and more rhomboidal compared to body scales ( Figs 1E–F). The rearmost scales (1.4 – 1.6 × 0.8 – 1.1 µm) are oval, lack a dome, and have a rudimentary reticulum formed by delicate ribs. Bristles (3.2 – 3.5 µm) are smooth, slightly curved and attenuated, with a sharp tip. The foot of the bristle is thin ( Figs 1G – J). Only one type of bristle was observed. Cyst unknown. Cell shape and dimensions unknown.

Habitat:— Small, humic pool.

Distribution:— South Africa, the species was only found in the type locality.

Etymology:— The epithet refers to the strong transversal rib, from Latin “temo” (pole or beam).