Trichosphaerium

This is actually a testate amoebae but is included here as is sometimes appears to be a Gymnamoeba, and Trichosphaerium has some similarity to certain amoebic groups.  The testate amoebae are classified as being a sub-class (Testacealobosia) within Class Lobosea (Sleigh, 1989).  The amoeba Pontifex maximus and Amoeba tentaculata are thought to be members of the genus Trichosphaerium (Page, 1983).  The genus was established by Schaudinn in 1899 published in a supplement to an obscure journal (Schaudinn, 1899), and contains organisms exclusively from marine environments.  A life cycle including schizonts and gamonts was proposed and evidence was discovered in other species, T. platyxyrum (Angell, 1976).  Trichosphaerium feeds on bacteria, algae, Dunaliella salina, Euglena gracilis (Angell, 1976) and various seaweeds (Polne-Fuller, 1987).  Although Schuster (Schuster, 1976) was not able to culture his strain of Trichosphaerium axenically, this was accomplished with another strain (Polne-Fuller, 1987).

After multiple fission the rsulting amoebae are small (20mm dia) and resemble other flabellate genera of amoebae such as Vannella, Platyamoba or Paramoeba (all Family Thecamoebidae).  Possible relationship to Sappinia? Sappinia is apparently in the Thecamoebidae family and is reported to have a sexual habit involving cell fusion like that described for Trichospherium. 

T. micrum (Angell, 1975)

T. platyxyrum (Angell, 1976)

T. sieboldi (Schaudinn, 1899)

T. maximus (Schaeffer,1926) If Page (Page, 1983) is correct in placing Pontifex maximus in Trichospaerium, then the size of T. maximus would make it likely that this is a different species and so is included here.

Angell, R.W. (1975). "Structure of Trichosphaerium micrum sp. n." J. Protozool. 22(1): 18-22.

Angell, R.W. (1976). "Observations on Trichosphaerium platyxyrum sp. n." J. Protozool. 23(3): 357-364.

Page, F.C. (1983). "Marine Gymnamoebae." Inst.Terr.Ecol. NERC Cambridge, England.

Polne-Fuller, M. (). "A multinucleate marine amoeba which digests seaweeds." Biosis 87: 317218

Polne-Fuller, M. (1987). "A multinucleated marine amoeba which digests seaweeds." J. Protozool. 34(2): 159-165.

Schaeffer, A. (1926) "Taxonomy of the amebas." Pap.Dept.Mar.Biol.Carnegie Institut. Wash. Vol XXIV, 1-116.

Schaudinn, F. (1899). "Untersuchungen uber den generationswechsel von Trichosphaerium sieboldi. Schn." Abh. Konigl. Preuss. Akad.Wiss., Berlin Suppl. 1-93.

Schuster, F.L. (1976). "Fine structure of the schizont stage of the testate marine amoeba, Trichosphaerium sp." J. Protozool. 23(1): 86-93.

Sheehan, R. & Banner, F.T. (1973). "Trichosphaerium - an extraordinary testate rhizopod from coastal waters." Estuarine & Coastal Mar.Sci. 1: 245-260

Sleigh, M (1989). "Protozoa and other Protists." Edward Arnold, London.