Molecular authentication of green algae Caulerpa (Caulerpales, Chlorophyta) based on ITS and tufA genes from Andaman Islands, India

Abstract

Indigenous and non-indigenous invasive algal species introduction or prevalence is one of the major concerns to protect the native coastal environment. Globally, several studies have reported the effect of invasive alga <em>Caulerpa</em> on coral reefs. To establish the genetic variation between indigenous and non-indigenous invasive species, attempts have been made to develop molecular identification of <em>Caulerpa</em> algal species available at the Andaman Islands. In this study, 7 visually and morphologically different species belonging to the genus <em>Caulerpa </em>(Chlorophyta) were collected from the intertidal regions of South and Little Andaman Islands, India. The specimens were preliminarily identified based on the morphological characters and genetically mapped using ITS2 and chloroplast <em>tuf</em>A gene markers. Six species of the <em>Caulerpa</em> viz. <em>Caulerpa racemosa</em>,<em> C. racemosa </em>var<em> lamourouxii</em>,<em> C. racemosa </em>var<em> macrophysa</em>,<em> C. serrulata</em>,<em> C. fergusonii </em>and<em> C. microphysa</em> were identified using ITS2 gene, and. <em>C. mexicana </em>var<em> pluriseriata</em> was identified using <em>tuf</em>A gene. Two varieties, <em>C. mexicana </em>var.<em> pluriseriata </em>and<em> C. racemosa </em>var<em> lamourouxii</em> were found to be invasive to Indian waters. These were earlier reported in Red sea and in Phillipine waters in the pacific ocean. Further studies are needed to elucidate the genetic divergence of the <em>Caulerpa</em> species present in Andaman waters using different molecular markers.