Lower and Higher Invertebrates with their differences

by

The invertebrates are usually classified as Lower Invertebrates and Higher Invertebrates.

Lower Invertebrates

  • The lower invertebrates are simple in body organization.
  • They are generally small in size.
  • These are thought to have originated in the main lines of evolution, near the base of the phylogenetic tree of Animal kingdom.
  • Lower Invertebrates includes Protozoa, Porifera, Coelenterata (Cnidaria), Platyhelminthes and Nematoda.

Higher Invertebrates

  • They possess a complex body organization.
  • They are generally larger in size.
  • These occupy a higher position in the phylogenetic tree of Animal kingdom.
  • Higher Invertebrates include Mollusca, Annelida, Arthropoda, and Echinodermata.

Lower and Higher Invertebrates

On the basis of some important features, there are some differences between lower and higher invertebrates as shown below:

Table 1: Differences between Lower Invertebrates and Higher Invertebrates

S.N.

Characteristics

Lower Invertebrates

Higher Invertebrates
1. Size Smaller in size Larger in size
2. Body organization Body organization simple Body organization complex
3. Symmetry Radial, biradial or no symmetry Bilateral symmetry
4. Germ Layers Germ layers wanting or 2 or 3 germ layers Three germ layers present
5. Coelom No Coelom or a pseudo-coelom True Coelom
6. Mouth and Anus Generally, no separate mouth and anus Mouth and Anus are separate
7. Muscular Gut Absent Present
8. Blood Vascular System Not well developed Well developed

Read Also:

 References

  1. Kotpal RL. 2017. Modern Text Book of Zoology- Invertebrates. 11th Edition. Rastogi Publications.
  2. Jordan EL and Verma PS. 2018. Invertebrate Zoology. 14th Edition. S Chand Publishing.

About Author

Sagar Aryal

Sagar Aryal is a microbiologist and a scientific blogger. He attended St. Xavier’s College, Maitighar, Kathmandu, Nepal, to complete his Master of Science in Microbiology. He worked as a Lecturer at St. Xavier’s College, Maitighar, Kathmandu, Nepal, from Feb 2015 to June 2019. After teaching microbiology for more than four years, he joined the Central Department of Microbiology, Tribhuvan University, to pursue his Ph.D. in collaboration with Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Saarbrucken, Germany. He is interested in research on actinobacteria, myxobacteria, and natural products. He has published more than 15 research articles and book chapters in international journals and well-renowned publishers.

4 thoughts on “Lower and Higher Invertebrates with their differences”

  2. Thanks so much for your service and sacrifice to find out this contents helpful for us university students in biology

    Reply

Leave a Comment