Are Arthropods Acoelomates Pseudocoelomates or Coelomates?

The protostome coelomates (acoelomates and pseudocoelomates are also protostomes) include the mollusks, annelids, arthropods, pogonophorans, apometamerans, tardigrades, onychophorans, phoronids, brachiopods, and bryozoans. Deuterostomes include the chaetognaths, echinoderms, hemichordates, and chordates.

Do acoelomates have a pseudocoelom?

Coelom is sometimes incorrectly used to refer to any developed digestive tract. Some organisms may not possess a coelom or may have a false coelom (pseudocoelom). Animals having coeloms are called coelomates, and those without are called acoelomates.

What are acoelomates pseudocoelomates and coelomates?

Bilateral animals can be characterized as lacking a body cavity (acoelomates). Those that have a body cavity, coelom, may have one that is incompletely lined with mesoderm (pseudocoelomates), or one that is completely lined with mesoderm (coelomates).