Biddulphia mobiliensis Bailey
Pavillard, 1925: p. 55, Fig. 96 (as Biddulphia mobiliensis);Hustedt, 1930: p. 841, Fig. 495 (as Biddulphia mobiliensis);
Allen and Cupp, 1935: p. 145, Fig. 80 (as Biddulphiamobiliensis); Cupp, 1943: p. 153, Fig. 110 (as Biddulphia mobiliensis); Crosby and Wood, 1958: p. 503, Pl. 36: 19 (as Biddulphia mobiliensis); Hendey, 1964: p. 104 Pl. XX: 3 (as Biddulphia mobiliensis); Hendey, 1970: p. 116 (as Biddulphia mobiliensis); Simonsen, 1974: p. 27; Ricard, 1987: p. 201, Figs. 432, 433; Throndsen et al., 2007: p. 176.
Cells single or rarely united in short straight chains by the long spines. Length of apical axis 45-157 µm; valves elliptical-lanceolate, convex, with a flat or nearly flat central part; valve processes slender, arising inside the margin of the valve, directed diagonally outward. Two long spines are placed far apart, but about equally far from the processes, directed obliquely outward, straight or often bent abruptly in their outer part. Cells relatively thin-walled,
without a sharp constriction between valve and girdle zone. Sculpturing fine, reticulate, 14-16 areolae in 10 µm on valve and valve mantle, 17-18 on girdle band. Auxospores formed as large bladders from the separation of the valves, with much larger cells inside. Microspores are observed (Cupp, 1943).
Cells length 65-70 µm; width 47-55 µm.
Neritic, truly planktonic; temperate and south temperate species.
Sites of occurrence in RSA:
In Winter 2006 Cruise, this species occurred at various sites (refer sites map), usually in small numbers; maximum abundance 10^2 cells/l) was associated with Iranian coast in the central part of the inner RSA (St. 27). It has been previously reported from the inner RSA (Simonsen, 1974) and from Kuwaiti shore (Hendey, 1970) and coastal waters (Al-Yamani et al., 2004; Al-Kandari et al., 2009).