The acoelomate hypothesis says that the coelom developed from an acoelomate progenitor.
Kinds of Coelomates.
These creatures have a pseudocoel (actually “bogus cavity”), which is a completely useful body hole. Tissue got from mesoderm just halfway lines the liquid filled body cavity of these creatures. In this way, despite the fact that organs are held set up freely, they are not too sorted out as in a coelomate. All pseudocoelomates are protostomes; notwithstanding, not all protostomes are pseudocoelomates.
Lack a vascular blood framework: Diffusion and assimilation circle supplements and waste items all through the body.
Protostomia and Deuterostomia.