Afrocymbella cocquytiana, Stone & Wilson & Jovanovska, 2022
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publication ID |
https://doi.org/ 10.11646/phytotaxa.556.1.3 |
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DOI |
https://doi.org/10.5281/zenodo.6951985 |
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persistent identifier |
https://treatment.plazi.org/id/03AC87E9-4550-FFAC-FF28-FF58FD120E80 |
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treatment provided by |
Plazi |
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scientific name |
Afrocymbella cocquytiana |
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sp. nov. |
Afrocymbella cocquytiana sp. nov. (LM Figs 87–108 View FIGURES 87–108 , SEM Figs 109–115 View FIGURES 109–111 View FIGURES 112–115 )
Description:— Valve length 35.0–51.5 μm, valve breadth 9.5–12.5 μm. Valves distinctly dorsiventral and heteropolar, semirhomboid-lanceolate ( Figs 87–115 View FIGURES 87–108 View FIGURES 109–111 View FIGURES 112–115 ). Dorsal margin broadly arched, slightly protracted near apices ( Figs 87–108 View FIGURES 87–108 ). Ventral margin weakly convex, barely tumescent in central area, tapering gently toward apices ( Figs 87–108 View FIGURES 87–108 ). Footpole narrowing, rounded with APF, headpole distinctly rostrate ( Fig. 109 View FIGURES 109–111 ). APF externally with round poroids ( Fig. 111 View FIGURES 109–111 ), internally covered by knobby jointed ridge of silica ( Fig. 114 View FIGURES 112–115 ). Internally, both poles bear small to indistinguishable pseudosepta ( Figs 112, 114, 115 View FIGURES 112–115 ). Axial area narrow, curved, slightly ventrally displaced ( Figs 87–108 View FIGURES 87–108 ). Central area small, broadly elliptical, slightly more arched on dorsal side ( Figs 109, 110 View FIGURES 109–111 ). A round stigmoid is present on dorsal side of central nodule ( Fig. 110 View FIGURES 109–111 ), opening internally through elongated slit ( Fig. 113 View FIGURES 112–115 ). Raphe curved and slightly sinusoidal ( Fig. 109 View FIGURES 109–111 ). External proximal raphe ends expanded into small pores ( Fig. 110 View FIGURES 109–111 ). External distal raphe terminal fissures deflected towards the ventral margin ( Figs 109, 111 View FIGURES 109–111 ). Internal proximal raphe ends covered by nodular or flap-like silica development formed by the primary side of the valve ( Fig. 113 View FIGURES 112–115 ). Internal distal raphe terminal fissures slightly elevated into small lobed helictoglossa at some distance from valve apices ( Figs 112, 114, 115 View FIGURES 112–115 ). Striae parallel in the middle, becoming radiate towards the valve apices ( Figs 109, 111 View FIGURES 109–111 ), 11–12 in 10 μm (central area) and approaching 14 in 10 μm (apices). Central-most striae often more widely and unevenly spaced. Striae continue uninterrupted onto valve mantle ( Fig. 109 View FIGURES 109–111 ). External areolae slit-like poroids ( Figs 109, 110 View FIGURES 109–111 ), appearing blocky in LM, 26–30 in 10 μm. Internal areolae ellipsoid without velum ( Figs 112, 113 View FIGURES 112–115 ).
Type:— REPUBLIC OF ZAMBIA. Upstream from the Kalambo River Falls, at 1220 m elevation, rock scrape, 8°35’47.0” S 31°14’22.3” E, A.Indermaur & F.Ronco, 8 th September 2018 (holotype designated here, circled specimen ANS-GC17198! = Fig. 93 View FIGURES 87–108 , isotypes circled specimens ANS-GC17199!, BM-101980!. Cleaned type materials: ANSGCM 33028. GoogleMaps
Registration: https://zoobank.org/NomenclaturalActs/468dba87-d6ff-4bfb-95f7-2f5c20b83e4f
Etymology:— The species name ‘ cocquytiana ’ honors Dr. Christine Cocquyt, who has contributed greatly to the diatom taxonomy of the African Rift lakes.
Distribution:— This species was only observed in abundance from the Kalambo River (Ka), which marks the boundary between Tanzania and Zambia ( Fig. 1 View FIGURE 1 ). We also observed a small population of this species in Isanga Bay (Is) in the southern sub-basin of Lake Tanganyika.
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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