Growth and reproductive biology of red alga Gelidiella acerosa (Rhodophyta) in the Mandapam region, east coast of India

Abstract

Growth and reproductive biology of G. acerosa (Forsskal) Feldmann el Hamel growing in a protected reef were studied monthly from March 1988 to February 1990. Growth rate, reproductive effort, number and distribution of stichidia, sporogenous tissue and shedding of 4 types of spores (mono-, bi-, tetra-, and polyspores) were measured. Seasonality in growth and reproduction was noticed without change in the morphology. Analyses of reproductive features gave a measure of fecundity of the alga. Seasonality in the output of spores (type wise) was also observed with a maximum during winter months, when seawater temperature was minimum 26-degrees-28-degrees-C. An estimate of the reproductive effort was given. Greater abundance of stichidia was recorded throughout the year with the peak in January. High percentage of sporogenous tissue in the stichidium, which showed preferential distribution in the secondary branches, was a special feature in its reproductive phenology.