Phylum: Porifera
Classification information for Poriferans:
Poriferans, better known as sponges, consist of 5000 known species, all located primarily in marine and fresh waters (Myers, 2001a). They are multicellular, heterotrophic, invertebrates with an irregular shape and no distinct pattern of symmetry (Myers, 2001a). Overall, they are the simplest of animals; thus, lacking any true tissue and/or germ layers (Myers, 2001a). Furthermore, they are known to be highly sessile, and feed by collecting bacteria from the water that streams through their porous bodies (Myers, 2001a). Feeding is known to be distinct, as their flagellated cells called choanocytes, trap bacteria in mucus, which allows them to then engulf the food …show more content…
Scyphozoa Alcyonacea Hydrozoa (class) (order) (class)
Kingdom: Animalia
Phylum: Platyhelminthes
Classification information for Platyhelminthes:
Platyhelminthes are known to be the simplest of bilateral animals- in addition to being multi-cellular, heterotrophic, and invertebrates (Myers, 2002). Typically, they can be found in marine water, freshwater, and general damp terrestrial habitats, being free living, but more than often parasitic (Myers, 2002). Additionally, platyhelminths are known to have three germ layers: an endoderm, ectoderm, and a mesoderm. The addition of the mesoderm allows animals to form true organ systems; however, this is all truly possible due to the mesoderm’s key feature, the coelom- a fluid-filled cavity that stores and protects the major organs (Myers, 2002). Furthermore, it should be noted that although platyhelminths have a cephalized nervous system that includes the head ganglion and interconnected nerve cords, they do not have respiratory or circulatory systems, or even a complete gut- which tells us that they are not that advanced (Myers, …show more content…
They are characterized to be multi-cellular, heterotrophic, invertebrates with bilateral symmetry, typically with simple body plans (Myers, 2001c). Specifically, nematodes are also classified as pseudocoloates- meaning that they have an incomplete body cavity; thus, they are unlike a true coelomate, whose body cavity is contained within the mesoderm, instead, they rather improvise one between the mesoderm and the endoderm (Myers,