Zoology 638 Thesis (Ph.D)-Zoology 66 Dissertations, Academic (Ph.D) 65 Invertebrates-- Zoology 59 Animals-- Zoology 56 Animal taxonomy-- Zoology 35 Crustacea and related animals-- Invertebrate Zoology 25 Crustacean and related animals-- Invertebrate Zoology 25 Collected works 24 Insects (Entomology)-- Invertebrate Zoology 23 Ecology 22 Mollusca & molluscoidea-- Zoology, Malacology 22 Chordate-- Vertebrate Zoology 21 Animals 19 Science 19 Marine animals-- Marine zoology 17 Physiology 17 protoplasm 17 Arthropod-- Invertebrate Zoology 16 Experimental Zoology-- Research 14 Mammals 14 Worms and related animals-- Nematology-- Helminthology-- Zoology 14 ZOOLOGY 14 enzymes 14 Malayalam; Zoology 13 Zoological Survey of India 13 Fishes 12 morphology 12 Biology 11 India 11