Thigmotaxis is not shown by

While trying to find out the characteristics of a newly found animal,a researcher performed histology on the adult animal and observed a cavity with the presence of mesodermal tissue towards the body wall,but no mesodermal tissue was observed towards the alimentary canal. What could be the possible coelom of that animal?

Megalecithal eggs are a characteristic of ..........

The cross-section of an animal body is given below:
Which of the following animals will satisfy the above cross-section?

Which of the following groups of animals are bilaterally symmetrical and triploblastic?

Which of the following is a pseudocoelomate animal?