Actinella hermes-moreirae Ruwer, Ludwig

Ruwer, Daiane T., Ludwig, Thelma A. V. & Rodrigues, Liliana, 2019, Two new diatom species (Bacillariophyceae) from Brazilian floodplain: Actinella hermes-moreirae sp. nov. and Gomphonema mutunensis sp. nov., Phytotaxa 395 (2), pp. 71-80 : 73-75

publication ID	https://doi.org/ 10.11646/phytotaxa.395.2.3
persistent identifier	https://treatment.plazi.org/id/EC0187CA-E53B-FFD2-BDBD-FF4EFED96F46
treatment provided by	Felipe
scientific name	Actinella hermes-moreirae Ruwer, Ludwig
status	sp. nov.

Treatment

Actinella hermes-moreirae Ruwer, Ludwig & Rodrigues, sp. nov. ( Figs 2–23 View FIGURE 2–23 , 24–31 View FIGURES 24–31 )

Frustules moderately arched. Valves dorsiventral and heteropolar. Length 13-38 μm, breadth 3-5 μm wide at median region (n=30). Dorsal margin convex and ventral margin linear to slightly concave. Headpole subcapitate, slightly dorsally bent. Footpole attenuated rounded. Raphe at the ventral margin of valve, reduced, with external distal ends slightly arched on the valve face. Helictoglossa distinct. Striae parallel to slightly radiate towards the poles, 16–18 in 10 μm, composed of continuous rows of rounded areolae, 4-5 areolae in 1 μm. Spines absent. A single rimoportula per valve on headpole or footpole.

Type:— BRAZIL. Paraná: Porto Rico, Ilha Mutum, Upper Paraná River Floodplain, swamp, periphyton, 22°45’31.98”S, 53°17’52.60”W, April 2016, D. T. Ruwer (holotype UPCB! 78281, here illustrated in Fig. 2 View FIGURE 2–23 ).

Etymology: —The species is named in honor of the pioneer Brazilian diatomist Dr. Hermes Moreira Filho (in memoriam), a researcher from Federal University of Paraná.

Material examined: — BRAZIL. Paraná: Porto Rico, Ilha Mutum , periphyton, 12-IV-2016, Ruwer et al. (78280 UPCB, 78281 UPCB) ; sediment, 27-II-2012, Ruwer et al. (78287 UPCB, 78296 UPCB - 78298 UPCB, 78300 UPCB - 78303 UPCB, 78305 UPCB, 78306 UPCB, 78313 UPCB) .

The new taxa A. hermes-moreirae presents asymmetric valves in relation to the transapical axis and a raphe system predominantly located at the valve mantle; therefore we have identified it as a species belonging to the genus Actinella ( Figures 2 View FIGURE 2–23 to 23).

A. hermes-moreirae sp. nov. ( Fig. 20 View FIGURE 2–23 ) shares similar valve formats with other species ( Table 1), such as Actinella leontopithecus-rosalia Costa (1995: 64), emend. Tremarin, Kim & T. Ludwig (2016: 261), A. eunotioides Hustedt (1952: 135) and A. lange-bertalotii Kociolek (2001: 148) . A. hermes-moreirae ( Fig. 20 View FIGURE 2–23 ) presents populations with smaller valve length in relation to the others taxa. A. lange-bertalotii Kociolek and A. leontopithecus-rosalia have narrower and longer headpole. A. eunotioides has lower striae density, elongated sub-capitate apices and commashaped raphe ends ( Metzeltin & Lange-Bertalot 1998, Kociolek et al. 2001). Basically, those taxa can be separated by the shape of distal raphe ends, and valve measures ( Table 1).