Question

How many classes of Hemichordata are there?

Answer 1

Hemichordata:

1. Hemichordate animals are all marine and deuterostomic.
2. They partly resemble the chordates.
3. Hemichordates are commonly known as a corn worm.
4. They possess stomochord instead of the notochord.
5. They have no post-anal tail and have an open circulatory system.
6. Classes of hemichordates:
   1. Enteropneusta:
      • Commonly known as tongue worms.
      • Marine animals that are solitary and burrowing.
      • Separate sexes
      • With or without tornaria larva.
      • Example - Balanoglossus, Saccloglossus, etc.
   1. Pterobranchia:
      • These are solitary or colonial, sedentary marine animals.
      • Sexes may be separate or united.
      • Direct development is mostly seen.
      • Some show the budding mode of asexual reproduction.
      • Examples - Atubaria, Rhabdopleura, etc.
   2. Planctosphaeroidea:
      • Few, rounded, small, transparent, and pelagic larva are seen.
      • Adult form is not known yet.