Morpho-molecular assessment of Acetabularia jalakanyakae Sp. Nov. (Dasycladales, Chlorophyta) - a new species from Andaman and Nicobar Islands, India

Abstract

Acetabularia (Dasycladales) is an extant genus of a single-celled green alga. There are four species of this genus reported from India, three reported from Andaman and Nicobar Islands. For this study, Acetabularia isolate was collected from a rocky intertidal habitat in the Andaman and Nicobar Islands. Light microscopy and Scanning Electron Microscopy were used for the morphological characterization. The distinct traits of caps of the thalli were prioritized because, traditionally, species delimitations in Acetabularia mainly were based on cap morphology. Our isolate showed morphological similarity with Acetabularia crenulata. However, the number of hairs in the inner ring of lobes of caps and the stalk length were observed to be different from A. crenulata and other closely related species. The phylogenetic tree constructed for partial 18S rDNA using the Maximum Likelihood (ML) method revealed the evolutionary affinity of this new species with Acetabularia dentata. Based on morphological and molecular synapomorphy, a new species of Acetabularia, Acetabularia jalakanyakae is formally proposed herein, and the further implications of this species discovery are discussed.