Cocconeis vrangoensis Al-Handal & Riaux-Gob., 2019
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publication ID |
https://doi.org/ 10.5852/ejt.2019.497 |
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DOI |
https://doi.org/10.5281/zenodo.5640702 |
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persistent identifier |
https://treatment.plazi.org/id/E8593F00-FFBD-FFB8-FE56-FE258E4FFD88 |
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treatment provided by |
Plazi |
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scientific name |
Cocconeis vrangoensis Al-Handal & Riaux-Gob. |
| status |
sp. nov. |
Cocconeis vrangoensis Al-Handal & Riaux-Gob. sp. nov.
Figs 10–15 View Figs 10–15 , 28–45 View Figs 28–36 View Figs 37–45
Differential diagnosis (LM)
Valves broadly elliptic to slightly rhombic, with round apices. Apical axis 13–16 µm (13.9 ± 2.6), transapical axis 12–14 µm (12.9 ± 0.6, n = 72). Raphe straight, ending slightly before apices. Striae parallel in the middle, becoming radiate towards the apices, 24–26 in 10 µm in the RV and 14–16 in 10 µm in the SV. RV with a silica ridge close to the valve margin and following the curvature of the valve, wider near the center and narrower towards the apices.
Etymology
The specific epithet of the new species refers to the location where it was collected.
Type material
Holotype ( Figs 11, 13 View Figs 10–15 : http://phycobank.org/1000795) SWEDEN • Vrångö Island , eastern side of Vrångö Island ; 57°34´N, 11°47´E; Aug. 2016; A. Al-Handal s.n. leg.; intertidal zone, as epiphytic on Ulva intestinalis ; BGBM, slide B 40 0 0 43105 . View Materials GoogleMaps
Isotype SWEDEN • Same data as for holotype; Department of Biological and Environmental Sciences, University of Gothenburg, slide V002 GoogleMaps .
Description (SEM)
Sternum valve
Convex on the external side, valve face flat to slightly depressed, with a wide mantle ( Fig. 30 View Figs 28–36 ). Axial area narrow and plain with no central area and terminating before the mantle ( Fig. 30 View Figs 28–36 ). Striae monoseriate becoming tri- to tetraseriate on the mantle. Virgae narrower than the striae and strongly raised on the internal valve face ( Fig. 29 View Figs 28–36 ). Areolae round to sub- quadrangular on both sides ( Figs 29–30 View Figs 28–36 ), sometime the septum between two adjacent areolae become very low or disappear and the areolae appear oblong with round corners ( Figs 28–29 View Figs 28–36 ). In SV internal side, the areolae are complex structure formed of 5–7 chambers (hymenate openings), one in the center and the others surrounding the central one ( Fig. 32 View Figs 28–36 ). The areolae on the mantle are long and composed of several small openings ( Fig. 31 View Figs 28–36 ). Each of these chambers is occluded by hymenes with linear perforations radially arranged ( Figs 32–33 View Figs 28–36 ). Valvocopula closed ( Fig. 36 View Figs 28–36 ), fimbriae thin, with finger-like extensions. On the advalvar side of the valvocopula, basal parts of the fimbriae are depressed and form grooves below the outer edge of the valvocopula ( Fig. 35 View Figs 28–36 ).
Raphe valve
Externally, RV slightly concave with marginal part of the mantle hyaline and void of areolae ( Figs 37– 45 View Figs 37–45 , arrow). Raphe straight, proximal raphe endings simple and close to each other, terminal raphe endings slightly widening and terminate shortly before apices ( Figs 37–45 View Figs 37–45 ). Axial area very narrow, central area round and small. RV striae uniseriate except on the mantle where they become biseriate. Areolae round and occluded by hymenes with thin perforations radially arranged ( Fig. 43 View Figs 37–45 ). Internally, the RV face is slightly convex with very narrow hyaline area on the inner side of the mantle which is strongly raised ( Figs 40–42 View Figs 37–45 ). Mantle margin folded inwards with a hyaline area void of areolae ( Fig. 41 View Figs 37–45 , arrow). Raphe straight, proximal raphe endings deflected in opposite directions, terminal raphe endings terminating shortly before the apices and with weakly developed helictoglossae ( Figs 40–42 View Figs 37–45 ). Axial area very narrow, central area small, strongly silicified, round and raised above valve surface ( Figs 40–42 View Figs 37–45 ). Valvocopula with long and thin fimbriae ending by a hammer-like structure with an oblong papilla ( Fig. 45 View Figs 37–45 , arrow). Between each pair of well-developed fimbriae there are short extensions that may be vestigial fimbriae ( Fig. 44 View Figs 37–45 , arrow).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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