Obsrevation

Gomphonema juettnerii B. Karthick, R. Nautiyal & J.P. Kociolek (Figs 1–16) Description: Valves clavate to narrowly lanceolate, headpole round and footpole narrowly rounded. Length 13.6 – 25.0 μm, breadth 3.6 – 4.8 μm. Axial area broad, lanceolate. Striae taper in
Table 1. Water quality variables of the type locality for the two new Gomphonema species, Nalota stream,collected December 2007.

Water quality variables                   Nalota Stream, Dehradun
Water Temperature (°C)                   20.44 ± 3.57

Velocity (m·s−1)                                0.30 ± 0.09
pH                                                     7.8 ± 0.13
Dissolved Oxygen (mgL–1)                10.78 ± 0.96
Total Hardness (mgL–1)                    74.56 ± 31.88
Alkalinity (mgL–1)                             60.11 ± 43.57
Phosphates (mgL–1)                        0.003 ± 0.001
Silica (mgL–1)                                    0.03 ± 0.03
U-nova144_karthick.indd                  166 16.07.2015 08

Two new species of Gomphonema (Bacillariophyceae)

Figs 1– 9. Light micrographs of Gomphonema juettnerii, from the type population; valve views showing the
size diminution series. Scale bar represents 10 μm.

width from the margins to the axial area. Striae are radiate-parallel, strongly radiate at the foot pole, 11–14 in 10 μm. Raphe lateral and undulate. External proximal raphe ends dilated. Stigmal opening is round. Septa and pseudosepta are present at the poles

SEM Morphology: In the SEM, the exterior of the valve is dominated by areolae with flaps that form c- or reverse c-shaped openings (Figs 10, 12). The undulate raphe has dilated proximalends, while the external distal ends are deflected onto the mantle in the same direction (opposite the side bearing the stigma) (Fig. 10). The external stigmal opening is small and round (Fig. 10). The bilobed apical pore field is physically separate, and morphologically distinct, from the striae and composed of rounded porelli that number ca. 60 in 10 μm (Figs 10, 12). Internally, the valvehas weakly radiate striae found in deep troughs, separated by thick interstriae (Figs 11–16). A small, slightly raised central nodule, helictoglossae, pseudosepta and the raphe slit are evident (Figs 13 –16). The central nodule has recurved proximal raphe ends and a rounded stigmal opening (Figs 13, 15). Helictoglossae are prominent at the head pole (Fig. 14) and foot pole (Fig. 16). Smaller struts help define the apical pore fields, which are covered internally by the pseudoseptum (Fig. 16).

holotype: Slide No. 552049, Diatom Collection, University of Colorado, Boulder, USA (COLO; Figure 3 = holotype). The valve representing the type is here illustrated as Fig. 3. Cleaned material accession number 9307.

isotype: Slide No. DS-05, Diatom Collection, Agharkar Research Institute Herbarium (AHMA), Pune, INDIA type locality: Nalota stream near deer park, Rajpur Road, Dehradun; Uttarakhand, India (leg. Rachna Nautiyal, December 2007).

etyMology: This species in named after Dr. Ingrid Jüttner, National Museum of Wales, Cardiff, United Kingdom in recognition of her contribution to the knowledge of Himalayan diatoms.

Figs 10 –12. Scanning electron micrographs of Gomphonema juettnerii. 10. External view of whole valve
showing “c” or “reverse c” shaped openings. 11. Internal view of the whole valve showing striae in deep
troughs. 12. External girdle view showing the areolae opening, apical pore fields and girdle bands. Scale
bar represents 1 μm.

Gomphonema doonensis B. Karthick, R. Nautiyal & J.P. Kociolek (Figs 17– 31)Description: Valves are clavate with a broadly rounded headpole and a narrow footpole. Thevalve tapers more strongly towards the footpole than to the headpole. Length 14.0 – 29.2 μm, breadth 4.5 – 5.5 μm. The axial area is narrow, straight and narrowly lanceolate in shape. The raphe is filiform and lateral. The rectangular-shaped central area is created by shortened striae on both sides of margin. Striae are costate and individual areolae are not visible in the LM. Striae are radiate, strongly radiate at the foot pole, 10 –14 in 10 μm. External proximal raphe ends dilated.Stigmal opening is round. Septa and pseudosepta are present at the poles.

Figs 13 –16. Scanning electron micrographs of Gomphonema juettnerii 13. Internal view of whole valve showing striae inside deep troughs and central area. 14. Internal view of the headpole showing prominent helictoglossae. 15. Internal view of the central area with recurved proximal raphe ends and a rounded stigmal opening. 16. Internal view of the footpole showing helictoglossae and pseudoseptum. Scale bar represents 1 μm.

SEM Morphology: In the SEM, the exterior of the valve shows striae composed of double rows of areolae across the valve (Figs 23, 25). Areolae are variously shaped, and may be round, tear drop-shaped or ellipsoidal (Figs 23, 25, 26). The undulate raphe has dilated proximal ends, while the external distal ends are deflected onto the mantle in the same direction (Fig. 23). The round external stigmal opening is present in the central area (Figs 23, 27). At the foot pole the distal raphe end bisects the apical pore field. In some specimens short striae composed of a single rowof areolae are positioned near the apical pore field (Fig. 28), but mostly striae are biseriate across the valve. The bilobed apical pore field is physically separate, and morphological distinct, from the striae and composed of rounded porelli, 68 –70 in 10 μm (Figs 25, 28). Internally, the valve has radiate striae found in deep troughs, separated by thick interstriae (Figs 29 – 31). A small,slightly raised central nodule has recurved proximal raphe ends and a slit-like internal stigmalopening (Figs 24, 30). Each distal raphe end terminates in a distinct helictoglossa at head pole (Fig. 29) and foot pole (Figs. 31). At the poles pseudosepta are visible (Figs 24, 29, 31)

Figs 17– 22. Light micrographs of Gomphonema doonensis, from the type population. 17– 21. Valve views
showing the size diminution series. 22. Girdle view of the valve. Scale bar represents 10 μm.

holotype: Slide No. 552-050, Diatom Collection, University of Colorado, Boulder, USA(COLO; Figure 17 = holotype). The valve representing the type is here illustrated as Fig. 17. Cleaned material accession number 9307.

isotype: Slide No. DS-05, Diatom Collection, Agharkar Research Institute Herbarium (AHMA), Pune, INDIA

type locality: Nalota stream near deer park, Rajpur Road, Dehradun; Uttarakhand, India (leg.
Rachna Nautiyal, December 2007).

etyMology: This species was found abundantly in Doon Valley and is named for its distribution.