Seasonal variation of reproductive and vegetative phases of Gracilaria pacifica Abbott, in Estero de Punta Banda, Baja California, Mexico

Abstract

The seasonal variation of the reproductive and vegetative phases of Gracilaria pacifìca Abbott was studied in two populations with different type of substrate, in Estero de Punta Banda, Baja California, Mexico. Thirteen field samplings were carried out from April 1986 to November 1987. Differences in type and phase dominance were observed in both populations. At station 1 (mud-sand), vegetative plants were dominant with maximum values in winter. Tetrasporic plants were more abundant in summer and less in winter. The absence of cystocarpic plants was evident and the few spermatangial plants were observed only in autumn-winter. At station 2 (pebbles and rock), vegetative and cystocarpic plants were dominant with maximum values in spring and summer, respectively. Tetrasporic plants were more abundant in summer and less in winter-spring. Spermatangial plants were present throughout the year, with maximum abundance in autumn-winter.