The sponges were considered to be plant-animal classification until 19th Century because they were not able to move, especially during their adult life where they attach themselves to a rock.
However, this paper aims to evaluate in a critical aspect about the notions that Phylum Porifera is paraphyletic rather than monophyletic. The essay achieves its purpose by providing credible sources to demonstrate the comparative knowledge of morphology and embryologoy in an effort of evaluating the suggested hypothesis. The paper demonstrates the suggestions of the notion in respect to bilaterian’s ancestors.
The sponges are among the simplest animals in the Kingdom Animalia. Their feeding system is unique among other types of animals. However, the evolution of animals is believed to transform the sponges from their earlier form of multi-cellular organisms to the present day animals. As earlier mentioned, it is learnt that Poliferans had an early branching event, which resulted to their separation from other metazoans. The sponges differentiate themselves from other animals in different nature such as lacking digestive, nervous, and circulatory systems. On their side, they adapt themselves by maintaining the constant flow of water through their pored bodies in order to get oxygen and food, as well as removing waste from the body.
In addition, their shape of the body is adaptive to maximal reliability of water flow though their central cavity, where it uses a hole called osculum to deposit the nutrients. Most of the sponge species feed on the food particles or bacteria in the water, where some of them host micro organisms for photosynthesizing processes to act as endosymbionts. Such associations ensure there is maximum production of oxygen and food in the water, as compared to what they consume. However, some sponges that live in environment with small or no food have become carnivores since they mainly prey on