Some Fresh Water Protozoa With Blue Chromatophores

Among the Protista blue is one of the rarest of the colors. The blue-green alga @ may be grass-green or shades of brown or red. A culture of a marine Spirulina I maintained for two years was constantly violet. Such variations in the color of the Myxophycele are due to combinations of chlorophyll, phycocyanin, and phycoerythrin, and to the make-up of the gelatinous envelope at times. Some Protozoa have a blue or violet color diffused through the cyto plasm as the ciliate, Stentor ca?reuleus Ehrenberg. Other Protozoa may occasionally have a blue color due to specific pigments contained in chromatophores. A single fresh-water rhizopod, Paulinella chromato phora Lauterborn, fulfills this condition, but most of the blue Protozoa are Mastigophora. Various marine Dinoflagellida have blue or blue green plastids, but according to Eddy (1930) none of the fresh-water armored species in the United States are so colored and I have been unable to find a record of such a species of Gymnodinium, the unar mored genus. The genera Chroomona.s and Cyanomonas of the Crypto monadida have blue chromatophores but Smith (1933) does not record the occurrence of either in this country; Pascher (1913), however, holds Cryptoglena americana Davis to be identical with Cvanornonas americana Oltmanns. West and Fritsch (1927) record Chroomonas nordstetii Hansgirg as reported once from England. From such scanty records of their occurrence it would be imagined that the blue Protista are very rare. In the past several years I have collected some hundreds of water samples from various field locations. Many of these have been centri fuged to concentrate their microOrganisms and examined before great temperature or other changes could occur. In such a sample taken from Newtown Creek at Collingswood, New Jersey, in 1932, I found a blue flagellate in abundance. Since then I have found Paulinella chro matophora, a new species of Chroomonas, and three other new flagel lates with blue chromatophores. I have also noted a rather widespread field occurrence of some of these organisms. Table I shows those which have occurred at nine locations.