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Name derivation:
Classification:
Asterolampra Ehrenberg, 1844. There are 95 species of which 8 have been taxonomically accepted. Order Asterolamprales; Family Asterolampraceae
Morphology:
Cells are discoid and solitary. Rarely occurs in large populations. Plastids are as numerous as the discoid bodies. Valves are saucer-shaped, without a distinct valve mantle, but with a radiating system of raised rays which expand to touch each other in the center (or stop short of the center in fossil species). Between rays the valve is areolate. Internally the rays are the bases of open chambers, the walls of which rise and sometimes curve over. A kidney-shaped rimoportula lies almost flat on the valve on the out end of each internal chamber. Adjacent to the chambers the foramina of the areolae are elongate giving a “ribbed” appearance.
Similar genera:
Can be confused with Asteromphalus, which always has one ray narrower than the others and is not symmetrical. Structure is also similar to Actinocyclus. Asteroactina is a genus closest to and originated from Asterolampra. The two genera have almost all of the same features, including radial rays attatched to every rimoprtula at the valve margin, broad longitudinal ray slits, and areolation restricted to the marginal annular field. Almost the only distinguishing feature between the two is that Asteroactina has an extra rimoportula other than the marginal ones on the valve face of the diatom (Komura 20017).
Habitat:
Marine, planktonic; mainly tropical.
References:
Ehrenberg, C.G. 1844. Mittheilung über 2 neue Lager von Gebirgsmassen aus Infusorien als Meeres-Absatz in Nord-Amerika und eine Vergleichung derselben mit den organischen Kreide-Gebilden in Europa und Afrika.Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königlich-Preussischen Akademie der Wissenschaften zu Berlin.: 57-97. Guiry, M.D. & Guiry, G.M. 2013. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 19 September 2013. Komura, S. 2007. Asteroactina: A new Asterolampra-like diatom genus with a solitary pericentral rimoportula. Diatom (23): 19-27.