Peanut worms of the phylum Sipuncula from the Nha Trang Bay (South China Sea) with a key to species Author Adrianov, Andrey V. Author Maiorova, Anastassya S. text Zootaxa 2012 3166 41 58 journal article 45619 10.5281/zenodo.279772 32627594-388c-40b3-8481-0b241b850847 1175-5326 279772 Apionsoma trichocephalus Sluiter, 1902 ( Fig. 4 E–F) Material. Nha Trang Bay: Diamond Bay, intertidal, coral rubble, 1 specimen . Description. Trunk spindle-shaped, 3–4 mm long, 1 mm wide; very thin introvert 10 X longer than the length of the trunk. Fold-like dorsal arc with 6 minute rudimentary tentacles, usually invisible in the dissecting microscope. Hooks scanty, barely visible, without accessory combs of spinelets, arranged in one incomplete ring. Discussion. This species differs from other representatives of the subgenus Apionsoma by having scanty hooks lacking spinelets and a reduced tentacular apparatus. Apionsoma trichocephalus is a circumtropical species, known from the Atlantic, Indian and Pacific Oceans. It inhabits sandy and muddy sediment from the intertidal to bathyal depths, and has been recorded in the West Pacific from New Zealand to Japan .