The genus Heterocapsa Stein is a relatively small armoured dinoflagellate. Because it has few differences in morphological characteristics among its species, species identification is difficult. In this study, small Heterocapsa sp. cells associated with a dense bloom of Cochlodinium polykrikoides Margalef were collected from the south-east coast of Iran. | Turkish Journal of Botany Research Article Turk J Bot (2013) 37: 778-783 © TÜBİTAK doi: The phylogeny of Heterocapsa sp. (Dinophyceae) isolated from the south coast of Iran during a Cochlodinium polykrikoides bloom Gilan ATTARAN-FARIMAN*, Pegah JAVID Department of Marine Biology, Faculty of Marine Sciences, Chabahar Maritime University, Chabahar, Iran Received: Accepted: Published Online: Printed: Abstract: The genus Heterocapsa Stein is a relatively small armoured dinoflagellate. Because it has few differences in morphological characteristics among its species, species identification is difficult. In this study, small Heterocapsa sp. cells associated with a dense bloom of Cochlodinium polykrikoides Margalef were collected from the south-east coast of Iran. While Heterocapsa sp. was isolated, C. polykrikoides could not be isolated by single cell or serial dilution methods. Thus, a unialgal strain of Heterocapsa sp. was used for molecular analysis and species identification. In order to carry out phylogenetic analysis, rDNA was extracted and large subunit domains of D1-D3 were sequenced. Similar sequences of other geographical strains were selected from GenBank and compared with the Iranian species. The Iranian strain was aligned with Heterocapsa spp. Phylogenetic analysis of maximum likelihood and neighborjoining demonstrated that Heterocapsa sp. does not form a monophyletic group. Morphological characteristics confirmed molecular results. This is the first record of Heterocapsa isolation from Iranian coastal waters. Key words: Cochlodinium, dinoflagellate, Heterocapsa, phylogeny, Oman Sea 1. Introduction Among the most important marine and freshwater organisms are phytoplankton (Solak et al., 2012; Kükrer & Büyükışık, 2013), and dinoflagellates are one of the most important constituents of marine phytoplankton (Polat, 2007). The genus Heterocapsa Stein is
