Non- indigenous ascidians in V. O. Chidambaram port, Thoothukudi, India

2147-2157<span style="font-size:9.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:calibri;mso-bidi-font-family:mangal;="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-US">V. O. Chidambaram port, formerly Tuticorin port, is one among the 12 major ports in India with regular services to United States, Europe, China, Red sea port and Mediterranean countries and so serving as gateway for bioinvasion. Ascidians belonging to the Class Ascidiacea of sub-Phylum Tunicata are abundant in many ports around the world and most of them are non-indigenous. They are one of the key ecological groups because of their invasive potential and ability to thrive in eutrophic environments. During a survey of the port area over the past three years (2011-2013), sixteen species of ascidians were identified belonging to diverse families: Ascidiidae (4), Styelidae (2), Pyuridae (4), Polycitoridae (2), and Didemnidae (4). Among the identified species, Phallusia nigra, P. arabica, Ascidia gemmata, Microcosmus exasperates, Herdmaniapallida, Eudistoma viride, E. laysani, Didemnum psammatode and <i style="mso-bidi-font-style: normal">Diplosomasimilis are classified as cryptogenic species while M. squamiger, M. stoloniferus, Styelacanopus, A. sydneiensis Didemnum candidum, Lissoclinum fragile and Eusynstyela tincta are invasive species. Presence of large number of cryptogenic and invasive ascidians in this harbour reinforces the need for continued and periodic monitoring of population expansion of these species and also for establishment of control programme. Utilization of non–indigenous ascidians for the betterment of humankind may be considered as one of management strategies of non–indigenous species.