Answer: Decreased surface to volume ratios to increase the efficiency of the gas exchange in air
Explanation:
The protostomes are coelomate invertebrates in which the mouth is been formed firstly from an opening called the blastopore. They are arthropods, mollusks, and annelids.The important difference between protostomes and deuterostomes is between the point of the blastopore. In protostomes, the blastopore is been developed into the mouth, and the opposite cavity develops into the anus. While In deuterostomes (the group that includes echinoderms and vertebrates ), the blastopore in been developed into the anus.
