Adlafia moseri Marquié, Le Cohu & Coste, 2018

Marquie, Julien, Cohu, Rene Le & Coste, Michel, 2018, Adlafia moseri and A. tjibaoui two new diatom species (Bacillariophyta) from New Caledonia with further observations on Adlafia muscora and Kobayasiella saxicola, Phytotaxa 357 (1), pp. 41-51 : 42-43

Adlafia moseri Marquié, Le Cohu & Coste sp. nov. ( Figs 2−18 )

LM ( Figs 2−13 ): Valves slightly triundulate to linear with rostrate apices. Valve dimensions (n=22): length: 28−50 μm, width: 6−10 μm, length/width ratio 3.2−6.4. Axial area narrow, slightly widening towards the central area. Raphe filiform. Proximal raphe endings weakly deflected to primary side. Central raphe pores simple, distant from each other. Striae discernible in LM, radiate, becoming more convergent towards apices, 26−30 in 10 μm.

SEM ( Figs 14−18 ): External striae pattern shaded ( Fig. 14 ). Central area bordered by few shortened and several long striae ( Figs 15, 17, 18 ). Internally, striae continuing uninterruptedly onto mantle, composed of rounded areolae ( Fig. 17 ). Proximal raphe endings straight, distant from each other ( Figs 15−18 ). Distal raphe endings terminating onto small helictoglossae ( Figs 15, 16 ). Small central nodule present on primary side of valve ( Fig. 17 arrow). Cingulum composed of at least three open copulae bearing two rows of pores ( Fig. 18 ).

Type: —Kué river: municipality of Yaté, NEW CALEDONIA (22.307° S, 166.964° E), benthic periphyton, Clémentine Flouhr, November 2011 (holotype PC! Slide no. 01455190, isotype: BR! slide no. 4481).

Etymology: —This species is dedicated to Gerd Moser honoring his important contributions to the diatom knowledge of New Caledonia.

Distribution and ecology: — Adlafia moseri was only found in ultra-oligotrophic running waters flowing on ultramafic soils in the southern part of New Caledonia. The new taxon is very rare and accompanied by a diatom community considered as strictly related to ultramafic substrate ( Moser, 1999). The species include Eileencoxia guillauminii (Manguin ex Kociolek & de Reviers 1996: 200) S.Blanco & C.E.Wetzel (2016: 196) , Gomphonema ricardii Maillard (1962: 67) , Brachysira angusta ( Maillard 1978: 153) Lange-Bertalot & Moser (1994: 12) , Achnanthidium indicatrix (Lange-Bertalot & Steindorf in Moser et al. 1998: 82) Lange-Bertalot (1999: 278), Frustulia neocaledonica Manguin ex Kociolek et de Reviers (1996: 200) .

Figures

FIGURES 2−13. Adlafia moseri sp. nov., valves views of the population from New Caledonia showing the variation in valve outline and size, LM. Scale bar =10 μm.

FIGURES 14−18. Adlafia moseri sp. nov. SEM. Fig. 14. External view of an entire valve showing the shadowed striae pattern. Fig. 15. Internal view of a valve. Voigt faults (arrows). Fig. 16. Internal view of a triundulate specimen. Fig. 17. Internal view, detail of the center of the valve. Small central nodule (arrow). Fig. 18. Internal view of a valve showing two open copulae with a row of pores. Scale bars = 10 μm (Figs 14−17), 2 μm (Fig. 18).