EVERYDAY SCIENCE

Detailed explanation-1: -The Hemichordata consist of three classes: Enteropneusta, Pterobranchia, and Planctosphaeroidea. Enteropneusts, or acorn worms (about 70 species), are solitary, wormlike, bilaterally symmetrical animals, often brilliantly coloured.

Detailed explanation-2: -acorn worm, also called enteropneust, any of the soft-bodied invertebrates of the class Enteropneusta, phylum Hemichordata.

Detailed explanation-3: -Balanoglossus and Saccoglossus are two hemichordata species.

Detailed explanation-4: -These animals are also called as Acorn Worms. They were initially grouped under Phylum Chordata. But, research has proven that none of these organisms does not have a post-anal tail or even the notochord, which is a distinguishing feature of chordates.

Detailed explanation-5: -Hemichordata /ˌhɛmikɔːrˈdeɪtə/ is a phylum which consists of triploblastic, enterocoelomate, and bilaterally symmetrical marine deuterostome animals, generally considered the sister group of the echinoderms.