Syvertsenia iberica Witkowski & Gomes 2013, sp. nov.
Creators: name: Gomes, Ana
name: Witkowski, Andrzej
name: Dąbek, Przemysław
name: Boski, Tomasz
name: Moura, Delminda
name: Szkornik, Katie
name: Kurzydłowski, Krzysztof
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Chromista
Ochrophyta
Bacillariophyceae
Cymatosirales
Cymatosiraceae
Syvertsenia
Syvertsenia iberica

description: Syvertsenia iberica Witkowski & Gomes sp. nov. (Figs 2–19)   
Valves linear with protracted to capitate apices, 21.4–28.6 (25.2 ± 2.9) µm long, 3.1–4.5 (3.7 ± 0.6) µm wide. Valves slightly arched about transapical axis. The mantle is shallow, except next to the process where a convex expansion of the valve mantle with an areolae situated above the process is observed. The whole valve surface is covered with areolae, except a small part of the valve in the middle which is close to the tubular process. The number of areolae in 10 µm varies between 17 and 20. Close to the process, there is a small oval area devoid of areolae (Figs 4, 6–8 and 11). The single tubular process is positioned on the extension of the valve mantle (Figs 3, 4, Figs. 6–8 and Fig. 10). The valve linkage consists of one row of marginal, short, Y-shaped linking spines at each side of the valve (Fig. 14). The row of linking spines terminates close to the ocelluli (Figs. 17 and 19). There are two ocelluli (with ca. 20 porelli each and small spines inside— Figs 16–19) set on the apices. The ocelluli are slightly displaced from the valve centre (Figs 10, 16–19).  
 Type: ⎯ SPAIN. Ayamonte: Guadiana Estuary, sandy flat near the river mouth (Fig. 1B), station GS1 (37º11’41’’N, 7º24’22’’W, Fig 1C). Sample collected from surface sediment by Ana Isabel Gomes on the 26 th of May, 2010. Holotype SZCZ slide 18916, illustrated in Figures 6 and 7; isotype slide no. 13298/ ALGU in the ALGU Plant and Algae Collection (Fig. 2).   
 Etymology: ⎯The specific epithet was chosen considering that Guadiana Estuary makes the border between the two countries that constitute the Iberian Peninsula.   
 Distribution and ecology: ⎯Thus far, known only from the type habitat area i.e. Guadiana Estuary, stations GS1, GS2 and GS18 (Fig. 1C). In the referred stations, the salinity of the sediment interstitial water ranges between 19.93 (GS1) and 30.74 g /Kg (GS18) while pH values varies from 7.27 (GS18) to 7.58 (GS2). The substrate grain-size preference varies between medium silt (GS18) and fine sand (GS2). In terms of organic carbon percentage it ranges from 0.36 % (GS2) to 3.40 (GS18). Table 3 presents in detail the physicochemical parameters measured at each sampling station. The river water column adjacent to the sampling stations presents a mean salinity of 26.43 ± 11.13 g /Kg, a pH of 8.20 ± 0.27, dissolved oxygen of 98 ± 19.48 % and a mean temperature of 17.88 ± 5.13º C.
description: Published as part of Gomes, Ana, Witkowski, Andrzej, Dąbek, Przemysław, Boski, Tomasz, Moura, Delminda, Szkornik, Katie & Kurzydłowski, Krzysztof, 2013, Syvertsenia iberica (Cymatosiraceae): a new estuarine diatom genus characterized by the position of its process, pp. 25-36 in Phytotaxa 142 (1) on page 30, DOI: 10.11646/phytotaxa.142.1.3, http://zenodo.org/record/5099883