On the morphology of the gametophytic generation of Padina gymnospora (Kuetz.) Vickers

Abstract

THE genus Padina has about a score of species of which P. gymnospora (Kuetz.) Vickers alone is known to have a discontinuous distribution, occurring on the one hand in the West Indies, and on the other in Mauritius and India (Kuetzing, 1859 ; Vickers, 1905, 1908 ; Boergesen, 1914, '30, '37, '41, '48 ; Taylor, 1942, '43). In both the regions the gametophytes of this species appear to be rare. Two oogonial specimens which were in the Berlin Botanical Museum were studied by Kniep (1928, pp. 178-85), but details were not given about their morphology and place of origin. The writer collected four oogonial and two antheridial plants 12.8 km. west - of Mandapam, at Puthumadam in the Gulf of Manaar, where they were obtained from shore-seine fishing nets which contained large numbers of tetrasporic plants as well. An oogonial plant and a few tetrasporic plants were dredged from a depth of 5.5 m. at 1.5 km. east of the place and 90 m. off-shore. An oogonial plant was found growing with numerous tetrasporic plants of the species, on Galaxea Reef (Krusadi I.), at a depth of 0.6 m. during low tide and another was found cast up at Pamban ; four oogonial plants were collected from a depth of 1.2 m. at low tide from Mandapam Camp (Palk Bay).