Phascolosoma (Phascolosoma) arcuatum (Gray)

Hsueh, Pan-Wen & Kuo, Chia-Ming, 2009, New records of sipunculan worms from Taiwan, Zootaxa 2067, pp. 51-61 : 58

Phascolosoma (Phascolosoma) arcuatum (Gray)

Figs 2 H, 3C

Phascolosoma (Phascolosoma) arcuatum Cutler, 1994: 163 , 167, 170, 172, 176, fig. 49D (for complete synonymy).

Material examined. Nine specimens (NMNS-5928-012), Kaomei tidal flat (24°19.34' N, 120°33.11' E), Taichung County, high intertidal sandy mud bottom, coll. P.-W. Hsueh, 22 December 1992; three specimens (NMNS-5928-013), Kaomei tidal flat (24°19.34' N, 120°33.11' E), Taichung County, intertidal sandy mud bottom, coll. P.-W. Hsueh, 25 April 1999; 4 specimens (NMNS-5928-014), Kaomei tidal flat (24°19.34' N, 120°33.11' E), Taichung County, high intertidal sandy mud bottom, coll. P.-W. Hsueh, 8 March 2003; One specimen (NMNS-5928-015), Hambao tidal flat (24°00.23' N, 120°21.07' E), Changhua County, high intertidal sandy mud bottom, coll. H.-T. Hung, 11 July 2001; one specimen (NMNS-5928-016), Shenkuang tidal flat (24°09.50' N, 120°27.32' E), Changhua County, high intertidal sandy mud bottom, coll. H.-T. Hung, 11 July 2001; 7 specimens (NMNS-5928-017), Bajhang tidal flat (24°00.23' N, 120°21.07' E), Chiai County, high intertidal sandy mud bottom, coll. H.-T. Hung, 17 January 2007; One specimen (NMNS-5928-018), Fubao tidal flat (23°59.28' N, 120°21.05' E), Changhua County, high intertidal sandy mud bottom, coll. H.-T. Hung, 11 July 2001; 5 specimens (NMNS-3636-058), Yunsen (24°29.34' N, 118°32.44' E), Kinmen County, high intertidal sandy mud bottom, coll. H.-T. Hung, 21 February 2001.

Remarks. The external morphology of the present specimens agrees well with descriptions of the species in Cutler (1994); the species has large and dark papillae set off from the skin, the introvert is up to twice the trunk length, there are more than 100 complete and incomplete rings of hooks (about 40–70 um tall), basally with greatly expanded clear streak and it is without secondary teeth, warts, or toes ( Cutler, 1994: 170, fig. 49D; present study, Fig. 3 C). It is commonly seen in the Indo-West Pacific region (from northeastern India to southern China) and known to tolerate brackish-water environments.

Figures

FIGURE 2. A, Sipunculus robustus Keferstein. B, Siphonosoma funafuti (Shipley). C, Siphonosoma vastum (Selenka and Bülow). D, Golfingia margaritacea margaritacea (Sars). E, Golfingia muricaudata (Southern, 1913). F, Thysanocardia nigra (Ikeda). Scalebars: A-E, 10 mm; F, 2.5 mm. G, Themiste minor minor (Ikeda), H, Phascolosoma arcuatum (Gray). I, Phascolosoma glabrum glabrum (Sluiter). J, Aspidosiphon (Aspidosiphon) muelleri Diesing. K, Aspidosiphon coyi de Quatrefages. Scalebars: G, 5 mm; H – J, 10 mm; K, 2.5 mm.

FIGURE 3. A, Introvert hooks of Siphonosoma vastum (Selenka and Bülow). B, Anterior close-up view of Themiste minor minor (Ikeda), showing posteriorly orientated hooks. C, Introvert hooks of Phascolosoma arcuatum (Gray). D, Introvert hooks of Phascolosoma glabrum glabrum (Sluiter). E, Anal shield of Aspidosiphon muelleri Diesing. F, Introvert unidentate hook of Aspidosiphon muelleri Diesing. G, Anal shield of Aspidosiphon coyi de Quatrefages, showing grooves on the surface of anal shield. H, Introvert hook of Aspidosiphon coyi de Quatrefages, showing a small secondary tooth on the hook. Scalebars: A, 100 μm; B, E, G, 1 mm; C – D, 80 μm; F, 10 μm; H, 20 μm.