Description
Unstalked heliozoa with an outer vacuolated 'ectoplasm ' and a more central granular, denser 'endoplasm '. The surface is covered by mucus . With a central homogeneous axoplast . With many small nuclei distributed throughout the endoplasm . Monotypic ; marine . References: Jones (1976), Febvre-Chevalier (1975) . OTHER HELIOZOA A number of taxa of uncertain affinities have a he liozoan -like appearance and have been Included as heliozoa in earlier treatments (Rainer , 1 968; Febv re- Chev al ier , 1985). We consider these organisms here , assuming that later work w iII establish their affinities more clearly . G e nus Sticholonche Hertwig , 1877 Large , marine, pelagic protists with 50-60 rows of motile oar-like pseudopodia inserting into depressions on the surface of a large , single , central nucleus. Body heart-s haped , bilaterally symmetrical , dorsoventrally compressed . The outer cytoplasm contains numerous small , curved , siliceous, tangential spicules and has 1 4 rosettes of long, external , radial spicules . The microtubules of the axonemes are arranged in irregular hexagons. Often treated as an order-the Taxopodida Fol , 1883. Reference: Cachon and Cachon (1977). Genu s Wagnerella Mereschkowsky , 1878 Stalked heliozoa with a spherical 'head ' supported by a cylindrical , non-contractile cytoplasmic stalk with an enlarged base. The nucleus is at the base of th e sta lk. The center of the head is occupied by an axoplast comprised of a central element surrounded by granular material. The head is covered by mucilage with associated small , tangential , siliceous (?) spicules. Reproduction by multiple budding which produces amoeboid cells from the head like Actinocoryne and also from the base. A complex life cycle described by Zuelzer (1909) needs verification . Monotypic ; the single marine species, W. borealis, may possibly be a gymnosphaerid. Reference : Zuelzer (1909) . Enjumet , 1954).
Type species
Gymnosphaera albida Sassaki, 1894
Figures
Raw text
Unstalked heliozoa with an outer vacuolated 'ectoplasm ' and a more central granular, denser 'endoplasm '. The surface is covered by mucus . With a central homogeneous axoplast . With many small nuclei distributed throughout the endoplasm . Monotypic ; marine . References: Jones (1976), Febvre-Chevalier (1975) . OTHER HELIOZOA A number of taxa of uncertain affinities have a he liozoan -like appearance and have been Included as heliozoa in earlier treatments (Rainer , 1 968; Febv re- Chev al ier , 1985). We consider these organisms here , assuming that later work w iII establish their affinities more clearly . G e nus Sticholonche Hertwig , 1877 Large , marine, pelagic protists with 50-60 rows of motile oar-like pseudopodia inserting into depressions on the surface of a large , single , central nucleus. Body heart-s haped , bilaterally symmetrical , dorsoventrally compressed . The outer cytoplasm contains numerous small , curved , siliceous, tangential spicules and has 1 4 rosettes of long, external , radial spicules . The microtubules of the axonemes are arranged in irregular hexagons. Often treated as an order-the Taxopodida Fol , 1883. Reference: Cachon and Cachon (1977). Genu s Wagnerella Mereschkowsky , 1878 Stalked heliozoa with a spherical 'head ' supported by a cylindrical , non-contractile cytoplasmic stalk with an enlarged base. The nucleus is at the base of th e sta lk. The center of the head is occupied by an axoplast comprised of a central element surrounded by granular material. The head is covered by mucilage with associated small , tangential , siliceous (?) spicules. Reproduction by multiple budding which produces amoeboid cells from the head like Actinocoryne and also from the base. A complex life cycle described by Zuelzer (1909) needs verification . Monotypic ; the single marine species, W. borealis, may possibly be a gymnosphaerid. Reference : Zuelzer (1909) . Enjumet , 1954).