Embryological Characteristics of Protostomes and Deuterostomes

The upcoming discussion will update you about the difference between embryological characteristics of Protostomes and Deuterostomes.

Difference # Protostomes:

1. Cleavage of Protostomes are spiral, determinate or mosaic. Bilateral-mosaic cleavage of some protostomes (e.g., nematodes).

2. In Protostomes, the blastopore either becomes the mouth, the anus forms a new structure (e.g., most of molluscs) or the blastopore gives rise to both mouth and anus (e.g., some molluscs, polychaetes, onychophores).

3. In Protostomes, modes of mesoderm development is from mesentoblast (some-times called 4d; it indicates the blastomere in 8-cell stage and by proliferation, develops mesoderm).

4. Coelom formation in protostomes is schizocoely (splitting of mesodermal bands).

5. Type of larva of protostomes is trochophore.

Difference # Deuterostomes:

1. Cleavage of Deuterostomes is  radial, inderminate or regulative of many deuterostomes. Bilateral-mosaic cleavage of some deuterostomes (e.g., sea squirts).

2. In Deuterostomes, the blastopore usually be-comes the anus and mouth forms a new structure.

3. Deuterostomes develops as out-folds of the archenteron.

4. Coelom formation in Deuterostomes is enterocoely (coelom is segregated as epithelial out pockets of the archenteron).

5. Type of larva of deuterostomes is  dipleurula.