FIGURE 5. A–C. Aspidosiphon elegans. A in Peanut worms of the phylum Sipuncula from the Nha Trang Bay (South China Sea) with a key to species

FIGURE 5. A–C. Aspidosiphon elegans. A) lateral view, introvert everted; B) bidentate hook; C) conical hook. D–H. A. gracilis. D) lateral view, introvert half everted; E) anal shield; F) caudal shield (white arrowhead - caudal shield.); G) hooks; H) the base of hooks (black asterisk - bifurcated posterior edge of hooks). I–J. A. muelleri. I) lateral view, introvert everted; J) hooks. K–L. A. laevis. K) lateral view, introvert everted; L) hooks. M-Q. A. steenstrupii. M) lateral view, introvert everted; N) close-up view of the introvert with calcareous anal shield (white arrow, calcareous cap on anal shield); O) bidentate hook; P) bidentate hooks & papillae; Q) pyramidal hooks. R-S. A. tenuis. R) lateral view, introvert everted; S) hook. Scale bars: A, 5 mm; B, 20 µm; C, 50 µm; D, 5 mm; E–F, 1 mm; G–H, 50 µm; I, 5 mm; J, 20 µm; K, 5 mm; L, 20 µm; M–N, 5 mm; O, 50 µm; P, 25 µm; Q, 50 µm; R, 5 mm; S, 50 µm.