INVESTIGATIONS ON RHODOPHYTA FROM THE COAST OF KARACHI WITH SPECIAL REFERENCE TO NEMALIALES

Nine species of Rhodophyta belonging to the families of Liagoraceae. Galaxauraceae. Gelidiaceae and Hypneaceae have been extensively collected from Karachi and the adjoining coastal areas and for the first time investigation circumscribing their external characters. Anatomical structures, development of their reproductive bodies and post fertilization changes as well as their growth patterns. Out of these, five viz. Dermonema abbottiae. Gelidium usmanghanii. Helminthocladia nizamuddinii. Scinaia Saifullahii and S. shameelii have been described as new species and two viz. Gelidium pusillum subsp. pakistanicum and Scinaia moniliformis subsp. pakistanensis as new subspecies. The general Dermonema Harvey ex Heydrich and Helminthocladia J. Agardh have been reported for the first time from the coast of Pakistan and Hypnea pannosa J. Agardh is also a new record from this areaApart from Gelidium pusillum (Stackhouse) Le jolis and Scinaia shameelii sp. nov., the other seven species have also been investigated phycochemically to document their fatty acid and sterol profiles. Saturated and unsaturated fatty acids present in these species have been analysed qualitatively as well as quantitatively. The sterols having cholestan, stigmastan and cycloartan nuclei were isolated and their structures determined. A variety of novel compounds e.g. brominated sesquiterpones were isolated and determined from Hypnea pannosa J. Agardh. All the isolated chemical constituents are the first report from respective species.