The breeding season of the Asterias rubens occurs in the spring. A sea star is sexually mature after one year of development. Sea stars may reproduce sexally or asexually. Asexual reproduction involves division of the disk and regeneration of each half. Sexual reproduction involves the production of sperm and eggs by separate female and male sea stars. Fertilization occurs outside the individuals in the seawater.
During embryo development, the Asterias rubens forms a blastula, which in three days forms the larva with structures such as the gut, anus, and coelom.
Populations of Asterias rubens have been found to be infected with the ciliate Orchitophrya stellarum. This parasite infects only male sea stars causing a variety of damage, including mechanical damage to the gonads, alteration in the host's hormonal pattern, and direct consumption of gonadal tissues. This decreases the reproductive potential of a population and may reduce the proportion of males to females. Fortunately, the decline in the number of males within a population, increases the likelihood of larvae survivorship because of increased food availability. (Bullough 1950; Pearse, et al 1987; Borradaile and Potts 1963)