Horizontal acquisition of Symbiodiniaceae in the Anemonia viridis (Cnidaria, Anthozoa) species complex

Abstract

From their earliest development stages, all metazoans live in close association with different microorganisms (symbionts) forming a so-called holobiont (Margulis & Fester, 1991). The evolution of these holobionts is influenced by the transmission mode of symbionts. Two modes of symbiont acquisition have been described: from the parents or from the environment, called vertical transmission and horizontal acquisition, respectively. Vertical transmission is traditionally more associated with mutualism, whereas