Sipunculoidea

...A general term for invertebrates belonging to the phylum Sipuncula. They live in the sea, in sand and mud, in rock crevices, in the crevices of coral reefs, between the roots of seaweed, and inside dead horn shells. There are about 140 species in the world, some of which are used as fishing bait. Their bodies are cylindrical and unsegmented, with a thin snout at the front and a thick trunk at the back. They are about 2 to 20 cm long, and their body colors include pale pink, gray, yellow-gray, and blue-green. An opening is formed at the tip of the snout, and several to several dozen tentacles, which may be finger-shaped, tufted, or arborescent, are lined up around it. ...

*Some of the terminology that mentions "Sipunculoidea" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…星口（ほしぐち）動物門Sipunculaに属する無脊椎動物の総称。海産で砂泥中や岩の割れ目，サンゴ礁の隙間，海藻の根部間，死んだツノガイの中などにすむ。世界で約140種あり，一部のものは釣りの餌に用いられている。　体は円筒状で体節はなく，前方の細い吻（ふん）と後方の太い体幹部とからなる。体長は2～20cmほどで，体色は淡紅色，灰色，黄灰色，青緑色などがある。吻の先端には口が開いていて，その周囲に指状，房状や樹枝状などの触手が数本～数十本並んでいる。…

※「Sipunculoidea」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報