Eunotia pacificomonodon Bąk, Kociolek, Lange-Bertalot, Łopato, Witkowski, Zgłobicka & Seddon, 2017, sp. nov.
Creators: name: Bąk, Małgorzata
name: Kociolek, John P.
name: Lange-Bertalot, Horst
name: Łopato, Daria
name: Witkowski, Andrzej
name: Zgłobicka, Izabela
name: Seddon, Alistair W. R.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Chromista
Bacillariophyta
Bacillariophyceae
Eunotiales
Eunotiaceae
Eunotia
Eunotia pacificomonodon

description: Eunotia pacificomonodon sp. nov.  Lange-Bertalot, Bąk & Kociolek   
Figs 88–106  
 Description: —Light microscopy—Valves arched with non-parallel margins. Dorsal margins arched convex than ventral margins curved concave. Ends protracted, subcapitate, ending with slightly cuneate outlines. Length 55–80 μm, breadth 8–10 μm (n=20). Terminal raphe nodule close to valve pole. Terminal raphe fissures on valve face very long, parallel to valve pole, extending to dorsal margin. Striae rather evenly spaced, 10–11 in 10 μm, becoming slightly denser near valve poles, 12–13 in 10 μm. Areolae difficult to resolve with light microscopy on valve face but rather coarse on copulae in girdle view, where ca. 15 in 10 μm (Fig. 100).   
Scanning electron microscopy:—Valve face and valve mantle positioned at right angle. Each stria positioned in shallow groove. Shortened striae present on abvalvar margin of valve mantle (Fig. 106, arrow). Dorsal or polar spines lacking. External opening of areolae simple round or elliptical. Areolae density 30 in 10 μm. External raphe slit long and slightly deflected on valve face (Fig. 104 —arrow).  
 Type: — ECUADOR. Galápagos Islands: Isabela (Albemarle) Island, Diablas wetlands, 0.95731°S, 90.98685°W, 23 July 2012, holotype (designated here):—Slide no. 20779 (species code—7874 MCCDRS) in Coll. Herbarium (CDS) of the Charles Darwin Foundation at Galapagos, represented by Fig. 95.   
 Type locality: —Floating moss, at the mouth of the stream to the lagoon in the Diablas wetlands—a permanent, brackish coastal lagoon network located at sea level on the south side of Isabela Island.   
 Etymology: —The composite name refers to location at one of the Galápagos Islands in the Pacific Ocean and resemblance to E. monodon.   
 Distribution: —Species so far found only in one sample.   
 Comments: —The newly established E. pacificomonodon most closely resembles a group of taxa including: E. monodon Ehrenberg (1843: 414), E. metamonodon Lange-Bertalot et al. (2011: 153), E. monodontiforma Lange-Bertalot & M. Nörpel in Rumrich et al. (2000: 121), E. major (W. Smith 1856: 14) Rabenhorst (1864: 72) (detailed comments are given in the comprehensive monograph of Lange-Bertalot et al. 2011). As explained more thoroughly in the discussion, the differences in measurements of the newly established species and the above listed taxa merit the description of E. pacificamonodon as new species.
description: Published as part of Bąk, Małgorzata, Kociolek, John P., Lange-Bertalot, Horst, Łopato, Daria, Witkowski, Andrzej, Zgłobicka, Izabela & Seddon, Alistair W. R., 2017, Novel diatom species (Bacillariophyta) from the freshwater discharge site of Laguna Diablas (Island Isabela = Albemarle) from the Galapagos, pp. 201-224 in Phytotaxa 311 (3) on pages 211-213, DOI: 10.11646/phytotaxa.311.3.1, http://zenodo.org/record/13700630