Pautas metodológicas para el estudio de Polycystina (Protozoa, Radiolaria).

BOLTOVSKOY DEMETRIO

PHYSIS - A

ASOCIACIÓN ARGENTINA DE CIENCIAS NATURALES

Lugar: Buenos Aires; Año: 1977 vol. 37 p. 33 - 41

0325-0342

Although the importance of Radiolaria from the biological point of view, as well as for paleontological purposes, has been thoroughly proved, no detailed accounts on the methodology used for their investigation have yet been available. Plankton samples should he taken with nets, rather than with pumps or bottles, and vertical tows should he performed with throttling devices, the mesh-aperture of the gauze being 0.3 to 0.06 mm. Extreme care should be taken to avoid contamination. Regular, non neutralized formaldehyde can be successfully used for the fixation of the samples; when cytological studies are the purpose of the collection, special fixation drugs and techniques should be used. Separation of the radiolarians from hulk-samples can he performed manually, with the aid of simple or mechanized pipettes; in this case studies of the living vs the dead fractions of the catch can be carried out by staining the organisms with Rose Bengal, Eosin, etc. Draining the sample through a filter-paper and picking the shells retained on the latter, or just mounting the filter- paper with the radiolarians on a slide, can also be done. When thorough identifications of the species are not necessary, regular phytoplankton and microzooplankton techniques, such as the Utermohl, centrifugation, sedimentation chambers and holographic photography can be applied. The elimination of organic matter and non-shelled plankton from bulk-samples can be accomplished hy ultraviolet-light treatments, or ashing the material in ovens or "plasma excitors". Ashes are sieved through a 0.035 to 0.060 mm mesh and mounted on slides with Canada balsam, "Caedax" or "Hyrax". Location of the specimens on the slides is determined with the aid of an "England Finder", and their illustrations obtained by means of light-photography and hand-drawings.