Phascolosoma (Phascolosoma) stephensoni (Stephen, 1942)

Açik, Şermin & Online, Published, 2014, Checklist of Sipuncula from the coasts of Turkey, Turkish Journal of Zoology 38 (6), pp. 723-733 : 730-731

Phascolosoma (Phascolosoma) stephensoni (Stephen, 1942)

Description: Body wall opaque, light brownish ( Figure 6E ). Preanal and posterior papillae cone-shaped, smooth, red in color; those on midtrunk small, hemispherical. Hooks with distinct smooth streak, triangular space, and crescent. Most hooks with distinct secondary tooth. Two pairs of retractors present. Two black eye spots present.

Distribution: Western and northwestern Indian Ocean, eastern Atlantic Ocean, western Pacific Ocean, and Mediterranean Sea ( Cutler, 1994; Açik, 2011).

Apionsoma (Apionsoma) misakianum (Ikeda, 1904)

Description: Body wall thin, semitransparent ( Figure 6F ). Small, numerous brown papillae on posterior part of trunk. Small hooks with basal spinelets (4–5) on introvert. Four thin retractor muscles originating near middle of trunk, both pairs close to ventral nerve cord. Bilobed nephridia usually similar in size, free; mostly orange in color; in some specimens, nephridia unequal in size. Nephridiopores located in front of anus. Two black eye spots present.

Distribution: Indian Ocean, Pacific Ocean, western Atlantic Ocean ( Cutler, 1994), and Mediterranean Sea (Açik, 2011).

Apionsoma (Apionsoma) murinae bilobatae (Cutler, 1969)

Description: Trunk cylindrical or flask-like ( Figure 7A ). Skin thin, transparent or thick, opaque, furrowed. Papillae on trunk globular, rosette sometimes dome-like shaped. Introvert with rings of hooks. Accessory comb with 4–6 spinelets at base of hooks. Ventral retractors thicker than dorsal ones. Nephridia mostly orange in color; one or bilobed; second lobe smaller than primary lobe. Nephridiopores located in front of anus.

Distribution: Western and eastern Atlantic Ocean, Mediterranean Sea, 2 sides of Indian Ocean ( Cutler, 1994; Açik, 2008).

Aspidosiphon (Akrikos) mexicanus (Murina, 1967)

Description: Body wall thin, light yellowish ( Figure 7B ). Anal shield weakly developed. Caudal shield not clear. Introvert at typical angle (45–50) with main trunk axis. Intestinal spiral attached to the posterior part of trunk by spindle muscle. Nephridiopores posterior to anus.

Figures

Figure 6. External morphology of species. A) Phascolion (I.) tuberculosum, B) Phascolion (P.) strombus strombus, C) Onchnesoma steenstrupii steenstrupii, D) Phascolosoma (P.) agassizii agassizii, E) Phascolosoma (P.) stephensoni, F) Apionsoma (A.) misakianum. Scale bars: A = 1 mm, B = 0.5 mm, C = 0.5 mm, D and E = 1 mm, F = 0.5 mm (A–E = Aegean Sea, original; F = from Açik, 2011).

Figure 7. External morphology of species. A) Apionsoma (A.) murinae bilobatae, B) Aspidosiphon (A.) mexicanus, C) Aspidosiphon (A.) elegans, D) Aspidosiphon (A.) misakiensis, E) Aspidosiphon (A.) muelleri. Scale bars: A = 1 mm, B and C = 2 mm, D = 1 mm, E = 2 mm (A–E = Aegean Sea, original).