Lemanea manipurensis sp. nov. (Batrachospermales), a freshwater red algal species from North-East India

Abstract

A new macroscopic riverine red algal species, Lemanea manipurensis sp. nov. (Batrachospermales) is described from Manipur in northeast India. It has a sparsely branched, pseudoparenchymatous thallus with a single, central axial flament that lacks cortical flaments. Spermatangia occur generally in isolated, low and indistinct patches or form an almost continuous ring around the axis. Carposporophytes project into the hollow thallus cavity without an ostiole. The most striking morphological feature is the carposporophyte with very short gonimoblast flaments having cylindrical, narrow and sparsely branched sterile flaments, the terminal cell of each branch with a single, large, elongate carpospore. The widely distributed L. fuviatilis has spherical carpospores in long branched chains. Phylogenetic analysis of rbcL sequence data and comparison with other Batrachospermales clearly show that our specimens do not align with other species of Lemanea and Paralemanea investigated thus far. Five specifc names attributed in previous literature (1973-2014) to Lemanea from Manipur, L. australis, L. catenata, L. fuviatilis, L. mamillosa, and L. torulosa are rejected until critical anatomical and molecular evidence is available for specimens from the Manipur river systems. Taxa referable to Paralemanea were not confrmed for India in this study. In view of the high demand for food and medical uses of L. ma-nipurensis in northeast India, conservation measures are needed for its long term survival. The present paper constitutes the frst combined morphological/molecular study on a freshwater red alga from India.