- echinoderms
- echolocation
- ecologist
- ecology
- ecosystem
- ectoderm
- ectoparasite
- ectotherms
- edentate
- egg
- eglantina
- electrophoresis
- element
- elongate
- emarginate
- embayment
- embedded
- embryo
- endangered
- endemic
- endoderm
- endoparasitic
- engraulids
- entomologist
- entomology
- environment
- Eocene
- epaxial
- epibenthic
- epibiosis
- epidermal
- epidermis
- epigonus
- epihyal
- epimesopelagic
- epipelagic
- epiphyte
- equator
- erectile
- estrus
- estuary
- ethmoid
- euhaline
- eukaryote
- euphausids
- euphotic
- euryhaline
- eurythermal
- eurytropical distribution:
- eusocial
- eutrophic
- evolution
- exserted
- extant
- external
- extinct
- extirpate
- extralimital
- eye