Spermcast mating with release of zygotes in the small dioecious bivalve Digitaria digitaria.

Digitaria digitaria, a small astartid usually less than 10 mm in length, has a non-brooding behaviour in spite of its limited space for gonad development. This species lives in highly unstable environments with strong currents, which represent a challenge for fertilization and larval settlement. The studied population of D.