Life Cycle
Brachiopod larvae are termed “lobate larvae”, but are considerably different between the Articulata and Inarticulata in terms morphology and timing of settlement. Articulate larvae have no mouth so settle after a planktonic period of several days, where they undergo reorganization from a three-part lobed larva to a sessile adult. The morphology of the Inarticulata larvae is similar to adults. They have a far longer planktonic period, at the end of which they gradually uncurl a pedicule and start secreting calcium carbonate or calcium phosphate (Lingulata) to form a shell, which, because it is heavy causes them to settle without such a dramatic metamorphosis as in the Articulata (Brusca and Brusca 2003).
