Appendix 3 - External Features of Pectinaria Adults
After removal of the sand test the most striking structures are the golden setae (paleae), bristles located at the anterior end. They are partially covered by a fimbriated antennular membrane (prostomium) that extends downward toward the mouth which is encircled by feeding tentacles. On the opposite dorsal side the golden setae are anchored in an oval cephalic plaque (peristomium) which acts as an operculum. Large external gills are located on body segments III and IV. Beginning with body segment V, pairs of prominent notopodial tufts of setae extend laterally. The reproductive gland and ducts (nephromixia) can be seen internally just inside of body segments VI and VII. In the midline the longitudinal pulsating heart can be seen through the semi-transparent body wall. It is also possible to see the gametes shifting back and forth in the coelomic fluid. (See Fig. 1 and Fig. 2)