Invertebrates

Invertebrates

1. Prorifera

   • Sponges, the members of the phylum Porifera, are a basal Metazoa clade as a sister of the Diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. The branch of zoology that studies sponges is known as spongiology.

2. Cnidaria

   • Cnidaria  is a phylum containing over 10,000 species of animals found exclusively in aquatic environments: they are a predominantly marine species. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell thick.

3. Flatworm

   • They are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates. Unlike other bilaterians, they are acoelomates (having no body cavity), and have no specialized circulatory and respiratory organs, which restricts them to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both ingestion (intake of nutrients) and egestion (removal of undigested wastes); as a result, the food cannot be processed continuously.

4. Nematode

   • The nematodes or roundworms constitute the phylum Nematoda (also called Nemathelminthes).[2][3] They are a diverse animal phylum inhabiting a broad range of environments. Taxonomically, they are classified along with insects and other moulting animals in the clade Ecdysozoa, and unlike flatworms, have tubular digestive systems with openings at both ends.

5. Arthropod

   • An arthropod  is an invertebrate animal having an exoskeleton a segmented body, and paired jointed appendages. Arthropods form the phylumEuarthropoda, which includes insects, arachnids, myriapods, and crustaceans. The term Arthropoda as originally proposed refers to a proposed grouping of Euarthropods and the phylum Onychophora

6. Mollusca

   • Mollusca is the second largest phylum of invertebrate animals. The members are known as molluscs or mollusks  Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species.

7. Echinoderm

   • Echinoderm is the common name given to any member of the phylum Echinodermata  of marine animals. The adults are recognizable by their (usually five-point) radial symmetry, and include such well-known animals as sea stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies".Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone.