There is more to the story of the creation , than what has been mentioned. One thing is that the interaction between 3 Gunas or the qualities and the 4 Mahabhutas or the Elements , 'Organs of perception ' and the organs of action ' and the body are formed , but not in the form that we see it . The Nature or the "Prakruti" has to act on it to have a final product of the body that we see. By the way in the human body Rajasic quality interacting with space element results in 'Speech ' , the element 'Air' or Wayu results in the development of the H and or the grasping ability , the element of 'Teja ' or the energy creates legs or locomotive ability. ability for the procreation and the excretion comes from the elements of the water and the earth respectively.
So the Astral body is formed by 24 principles , namely 5 organs of action , 5 organs of the perception, 5 Big Elements ( Prachamahabhuts ) , 5 Pranas ( energy ), the Mind (Manas ), the intellect ( budhhi ), the ego ( Ahankar ).and the feeling ( Chitta ). (In Revelation 8-8, there is mention of 24 'elders' which may be the same elements of the Astral body that we were talking . )
The entire visible universe is or can be divided in to 4 different categories.This has nothing to do with biology, i.e. birds, aquatic , mammals etc. But it is based on the concept of development of , or evolution of different " KOSHAS ".The 'stone' , the 'plant ' , the 'animal ' and the most evolved 'human beings '. There are 5 Koshas or the coverings . , namely the "Food " (Annamaya ) , the "Intellect " ( Dnyanmaya), the "Mind " (Manomaya ), the "Life "( Pranamaya ) and lastly the " Bliss" ( Anandamaya ) Each of these coverings are developed in the above mentioned 4 different categories in the physical universe. In the human beings all 5 are evolved , while in the " Stone "level, none is evolved. In the plant kingdom , the 'food ' and 'life ' are evolved. In animal stage the ' food ' , the 'life ' , the ' mind ' are evolved , ( may some intellect too . )The bliss covering is evolved or can be evolved only in the human beings.