This site has a brief description, images, and links to partial and total SSU sequences for Androsina lucasi, the type species of Androsina.
Total and partial 18S ribosomal RNA gene sequences are available for Androsina lucasi. These sequences can be accessed through the ForamBARCODING website (Jaquet 2010), and through the GenBank depository (Accession number AJ404301) (Holzmann and Pawlowski 2000). The 18S rRNA sequence of Androsina lucasi was originally used for a molecular phylogenetic analysis of soritacean foraminiferans (Holzmann et al. 2001).
Sequences for the 18S, 5.8S, 28S, ITS1 and ITS2 regions of the 18SrRNA are available for the Chlamydomonas endosymbionts of Androsina lucasi through the GenBank depository (Accession numbers AJ297795 and AJ297796) (Pawlowski et al. 2002a, b). These sequences were originally used for a molecular phylogenetic analysis of the chlorophycean endosymbionts that are associated with archaiasine foraminiferans (Pawlowski et al. 2001).
Androsina lucasi Lévy, 1977 is the genotype (type species) of the genus Androsina Lévy, 1977 by original designation (Lévy 1977: p. 418). The original publication states that the holotype is deposited in the Laboratoire de Paléontologie, Muséum national d’Histoire naturelle in Paris (F.G. 545). The paratypes are deposited in the Historical Geology laboratory of the University of Paris VI (Université Marie-et-Pierre-Curie).
Androsina lucasi was first described and figured by Lévy (1977: p. 418, pl. 6, figs. 1-15). The original description is as follows: “Test très comprimé, protéiforme, opaque. L’enroulement des individus juveniles est de type nautiloïde, involute, s’élargissant ensuite en forme de casque jusqu’à devenir flabelliforme à sub-annulaire au stade adulte. Loges en nombre variable, étroites, arquées, tres lisses et à stutures épaisses. La face orale est plane, orné d’ouvertures à bourrelets généraement dispoeees sur deux lignes chez les individus macrosphériques et plus rarement sur quatre chez les specimens microspheeriques. La structure interne est constituée dans les deux cas de plissotements sous-épidermiques très fins et d’une cloison équatoriale ajourée qui est soudée aux septa. Diamètre: jusqu’à 3 millimètres.”
The English translation of the above diagnosis is as follow: Test very compressed, variable in shape, opaque. The coiling of juvenile individuals is nautiloid, involute. The test then expands until it is helmet-shaped, becomig flabelliform to sub-annular in the adult stage. Chambers are variable in number, narrow, arched, very smooth, with thick sutures. The apertural face is flat, ornamented with rimmed apertures that are arranged in two rows in macrospheric individuals and more rarely in four rows in microspheric specimens. The internal structure is constituted in both cases of very thin sub-epidermal folds with a perforated equatorial partition which is welded to the septa. Diameter: up to 3 mm.
The foraminiferal species Androsina lucasi possesses a multi-chambered, planispirally coiled, compressed test (or shell) with a two-layered porcelaneous wall that is constructed of high-magnesium calcite. The juvenile stage of the test is involutely coiled; subsequent ontogenetic stages are evolutely coiled with a flabelliform mode of chamber addition. And, the terminal ontogenetic stage is uniserial and flaring. Sutures (contacts between chambers) are curved in the coiled stage, and strongly arched in the flabelliform and uniserial stages. The chambers are of relatively constant height, greater in width than height, with a chamber surface that is slightly inflated. The surface of the chambers is covered by rounded pseudopores that are approximately 3 µm in diameter, and occur at a density of 3-4 pits per 100 µm2. Each chamber possesses multiple apertures arranged in rows and situated in longitudinal furrows along the apertural face. Two rows of apertures are present in the last-formed chambers of megalospheric tests. Up to four rows of apertures are present in the last-formed chambers of microspheric tests. The apertures are oval in shaped and longitudinally elongated, and bordered by a rounded, imperforate rim. The apertural face is ornamented with haphazardly dispersed pseudopores. The internal structure of the chambers consists of narrow buttresses and a centrally located median blade.
Live individuals possess endosymbiotic chlorophyte algae that impart a characteristic blue-green coloration to their cytoplasm (Hallock and Peebles 1993, Lévy 1977, Pawlowski et al. 2001). The chlorophyte algal endosymbionts of Androsina lucasi are most closely related to Chlamydomonas hedleyi, the chlorophyte endosymbiont of Archaias angulatus (Lee et al. 1974), and other unnamed species of Chlamydomonas isolated from closely related archaiasine foraminiferans (Pawlowski et al. 2001).
