Difference Between Protostomes and Deuterostomes

The key difference between Protostomes and Deuterostomes lies in the development of their embryonic cells, with protostomes forming the mouth first during embryogenesis, while deuterostomes develop the anus first. Protostomes and Deuterostomes are two types of organisms with tubes within a tube body plan

The major difference between these two is based on the fate of Blastopore. In this article, we will cover the difference between Protostomes and Deuterostomes.

Protostomes

Proto’ means first and ‘stomes’ means mouth. Protostomes meaning the animals in which Blastopore forms the mouth first and then the anus. Blastopore is an opening seen during the gastrula stage for the movement of cells and is responsible for the formation of the mouth and anus. In Protostomes, a solid and ventral nerve cord is present. They exhibit determinate and spiral cleavage.

Protostomes Examples

Protostomes includes animals belonging to lower invertebrates like Annelida, Arthropoda, and Mollusca.

• Anthropoda – Butterflies, insects, crabs, and shrimps
• Annelida – Leeches, earthworms
• Mollusca – Octopus, snails, clams

Deuterostomes

‘Deutero’ means second and ‘stomes’ means mouth. This means that Deuterostomes are the animals in which Blastopore forms the anus first and then the mouth. In Deuterostomes, a hollow nerve cord is present. They exhibit indeterminate and radial cleavage.

Deuterostomes Examples

Deuterostomes includes Echinodermata, Hemichordata, and Chordata.

• Echinodermata – Starfish, sea urchins, and sea cucumbers
• Hemichordata -acorn worms, graptolithina
• Chordata – Humans, fish, mammals

Tube Within Tube Body Plan

An organism having two separate openings, one acting as a mouth and the other acting as an anus is said to have Tube within the tube body plan. It is called so because the alimentary canal which is a tube, is present within the body wall which is also a tube. This type of body plan is found in seven kingdoms, namely, Aschelminthes, Annelida, Arthropoda, Mollusca, Echinodermata, Hemichordata, and Chordata. There are two types of tubes within tube animals – Protostomes and Deuterostomes

Differences Between Protostomes And Deuterostomes

The key difference between Protostomes and Deuterostomes is given in tabular form below:

Features	Protostomes	Deuterostomes
Fate of Blastopore	Forms the mouth first and then the anus	Forms the anus first and then the mouth
Nerve Cord	Solid and ventral	Hollow
Cleavage	Determinate and spiral	Indeterminate and radial
Mouth Formation	Forms first from the blastopore	Forms second, from a new opening
Anus Formation	Forms later by invagination or from the blastopore	Forms first from the blastopore
Nervous System	Ventral nerve cord with paired ganglia	Dorsal nerve cord with single midline ganglia
Examples	Aschelminthes, Annelida, Arthropoda, Mollusca	Echinodermata, Hemichordata, Chordata

Conclusion – Difference Between Protostomes And Deuterostomes

In conclusion, understanding the differences between protostomes and deuterostomes is crucial for learning about animal biology. Protostomes develop their mouths before their anus, while deuterostomes develop their anus first, followed by the mouth. Additionally, protostomes have a solid and ventral nerve cord, whereas deuterostomes have a hollow one. Cleavage patterns differ between the two, with protostomes having determinate and spiral cleavage, and deuterostomes having indeterminate and radial cleavage. Understanding these features helps in categorizing and understanding the diverse array of life forms on Earth.

FAQs on Difference Between Protostomes And Deuterostomes

What is the Difference Between Protostomes and Deuterostomes?

Protostomes are animals in which the blastopore forms the mouth first and then the anus, whereas Deuterostomes are animals in which the blastopore forms the anus first and then the mouth.

What is the Role of the Blastopore in Embryonic Development?

The blastopore is an opening seen during the gastrula stage that allows the movement of cells. It is responsible for the formation of the mouth and anus in a developing embryo.

What is the Difference in Nerve Cord Structure Between Protostomes and Deuterostomes?

Protostomes have a solid and ventral nerve cord, while Deuterostomes have a hollow nerve cord.

How do Protostomes and Deuterostomes Differ in their Ceavage Patterns?

Protostomes exhibit determinate and spiral cleavage, whereas Deuterostomes exhibit indeterminate and radial cleavage.

 Are Human Deuterostomes?

Yes, humans are deuterostomes.

What are the Similarities Between the Protostomes and Deuterostomes?

Both protostomes and deuterostomes are multicellular organisms with bilateral symmetry and triploblastic tissue organization.