Dactyliosolen phuketensis Hasle

Division: Chromophyta
Class: Bacillariophyceae
Order: Biddulphiales
Suborder: Rhizosoleniineae
Family: Rhizosoleniaceae De Toni
Genus: Dactyliosolen Castracane
Scientific name: Dactyliosolen phuketensis (Sundström) Hasle

 

Cells cylindrical, living singly or united in long, stiff, closed chains by the flat valve surfaces.Valves circular, without noticeable spines or processes; on the margin, sometimes with indistinct little nodules. Intercalary bands numerous, half-collar-shaped, somewhat spirally twisted and with their wedge-shaped thin ends fitting together in a toothlike manner. Mantle surface with fine or coarse areolae. The ends of the intercalary bands do not always lie in an even line in the pervalvar direction, but sometimes form a spiral line. The girdle band is frequently unilaterally displaced and considerably closer to the younger valve (Cupp, 1943).

Synonym:
Rhizosolenia phuketensis Sundström

Reference:
Throndsen et al., 2007: p. 155.

Description:
Cells curved. Chains close set, curved or spiraling. Bands visible with LM (Throndsen et al.,2007).

Dimensions:
Cells length 85-94 µm; diameter 38-42 µm.

Distribution:
Warm water species.

Sites of occurrence in RSA:
In Winter 2006 Cruise, this species occurred at few scattered sites (refer sites map), usually in small numbers; maximum abundance did not exceed 10^3 cells/l and was associated with the Sea of Oman.