- decapod
- deciduous
- deep sea
- deep water
- demersal
- dentary
- denticles
- denticulate
- dentition
- dermal
- desmosomes
- detergency
- detritus
- diapause
- diatoms
- dichotomous
- dichotomy
- diel
- diffuse
- diffusion
- dilated
- dimorphic
- dinoflagellates
- dioecious
- diploid
- disjunct
- disjunct area
- disparate
- dispersal
- displacement
- dissected
- dissection
- distad
- distal
- distributed
- diurnal
- divergence
- diverticulae
- DNA
- dolphin
- domestic
- dorsal
- dorsum
- dune