Figure 28

Series of conventional light microscopy images of P. dumerilii , small atokous worm and heteronereis. All images: Dorsal view, anterior side left. A: Overview, small atokous worm with 48 chaetigerous segments. B: Head of the same specimen as shown in A, at a higher magnification. The dorsal and ventral branch of the anterior and posterior cirri are visible, as well as the palpi (pl), antennae (ant) and the well developed jaws (j). C: Posterior end of the same specimen at higher magnification, posterior to the last chaetigerous segment is the growth zone (gz) located where new segments are formed. D: Overview, male and female may be similarly sized. Female (♀), top, appears yellowish, due to the oocytes in the coelomic cavity. Male (♂) bottom, appears white due to spermatozoans in the anterior part and red due to dense accessory blood vessels in the posterior part. The parapodia (pp) in the posterior body part are flattened with paddle-like chaetae. E: Detail of the male and female body at a higher magnification. Note the numerous visible oocytes (ooc) inside the female's body and the different shape of the parapodia (pp) in the anterior and posterior body part. F: Anterior part of a mature male. Note the enlarged adult eyes (ae) in comparison to B. The dorsal cirri of the parapodia (dcpp) in segment three to nine are clearly club-shaped. D: Anterior part of a mature female, note also here the enlarged adult eyes (ae) and the oocytes inside the coelomic cavity and the parapodia. The dorsal cirri of the parapodia (dcpp) in segment three to seven are slightly club-shaped. Scale bar in A: 500 μm. Scale bar in B and C: 100 μm. Scale bar in D, E, F and G: 2 mm. Further abbreviations see abbreviations list.