Clot Formation in the Sipunculid Worm Themiste petricola: A Haemostatic and Immune Cellular Response
Figure 1
Themiste petricola, a species of the phylum Sipuncula, is shown in “peanut-shape” in (a) and in “worm-shape” in (b). Shape changes are due to contraction of the retractor and longitudinal muscles in (a), and relaxation of retractor and contraction of circular body wall muscles in (b). Intracoelomic pressure is higher in peanut-shape, and coelomic fluid may be strongly expelled if the body wall is ruptured while the worm is kept in this shape.
