56. Brown, Jr. R. M. 1975. Pleurochrysis
scherffelii (Haptophyceae). Vegetative development. Encyclopaedia
Cinematographica. Film E 1682 des Inst. Wiss. Film, Göttingen.
Research Film 8:491-500.
56. General Remarks
Pleurochrysis scherffelii
was described as a chrysophycean alga by PRINGSHEIM in 1955 [13].
The alga subsequently was placed in the family Phaeothamniaceae
by POTT [8]. When PRINGSHEIM described this alga, no zoospore
stages were known. Therefore, any haptophycean affinities of
this organism could not be confirmed. This was further complicated
by the fact that no one had observed the ultrastructure of Pleurochrysis.
In 1969, BROWN [1] discovered that Pleurochrysis produces
scales which are very similar to those known for the Haptophyceae.
Later investigations by BROWN et al. [4] revealed motile stages
demonstrating a very short haptonema located between two smooth
flagella. Although no formal transfer into the Haptophyceae has
been made, Pleurochrysis probably should be considered
within this class. Recently, BROWN and BLANKLEY (work in progress)
were successful in obtaining coccolith stages from Pleurochrysis
cultures. These observations strongly suggest that Pleurochrysis
is an alternant phase with the: coccolith-producing haptophycean
alga, Cricosphaera (LEADBEATER [12]). Until the life history
of this interesting organism is more thoroughly investigated,
the writer would like to defer a formal description.