Scale-bearing chrysophytes from tropical Northeast India

This is the first publication describing scale-bearing Chrysophyceae from India by means of electron microscopy. Twenty seven such taxa are described from samples for ponds, rivers and thermal springs. Twenty of these are Mallomonas spp.: M. akrokomos, M. bronchartiana, M. caudata, M. ceylanica, M. costata, M. crassisquanta, M. cyathellata var. cyathellata, M. cyathellata var. chilensis, M. cyathellata var. kenyana, M. guttata, M. heterospina, M. mangofera f. mangofera, M. mangofera f. foveata, M. mangoferea I. reticulata, M. matvienkoae I. matvienkoae, M. mat-vienkoae var. grandis, M. morrisonensis, M. peronoides, M. portae-ferreae , and M. tasmanica . Three are Synura taxa: S. curtispina, S. petersenii f. petersenii , and S. petersenii I. kufferathii . Two are Spiniferomonas species: S. coronacircumspina and S. enigmata. Paraphysomonas and Chrysosphaerella were each represented by one species: P. vestita and C. longispina . The water bodies from which these samples were taken were mostly eutrophic and nutrient rich. The majority of the taxa were obtained during the summer months when water temperatures were high. This contradicts the widely held belief that silica-scaled chrysophytes are mainly found in cold oligotrophic and mesotrophic waters. Mallomonas portae-ferreae and one unidentified species of Mallomonas were recorded also from thermal springs having water temperatures up to 50°C.