The Development of Audouinia tentaculata (Montagu)

Abstract

(1) Adults of Audouinia tentaculata Montagu were induced to spawn in the laboratory; the eggs were fertilized and the larvæ reared to metamorphosis and early bottom stages for the first time.(2) The larvæ are yolky and do not feed. They have a broad prototroch and telotroch and a broad neurotroch. The ciliation of the head is rather complex. There are no bristles. When about ten days old they metamorphose.(3) During metamorphosis most of the cilia, except those of the neurotroch, disappear and their cells are absorbed internally.(4) Bristles appear for the first time a few days after metamorphosis. After a while branchiæ appear, followed by what are apparently tentacular filaments situated on segments anterior to those on which they occur in the adult.(5) Discussion centres on the position of the tentacular filaments and the first pair of branchial filaments in the young worm as compared with the adult. The segmentation of the anterior achaetigerous region also receives attention.