Ecomorph: A population of a species having small differences in morphology. Represents adaptations to very local environmental variations. Became reproductively isolated from others very recently.
Ecotone: Narrow but fairly defined transition zone between two or more different communities or ecosystems. Arise naturally. Species rich. Example: Transition zone between a grassland & a forest.
Ecotype: Subspecies or population of a widespread species adapted to local particular set of environment i.e. a locally adapted population of a species. Show minor changes in morphology and/or physiology w.r.t. their habitat. Changes are genetically induced. Able to reproduce with other ecotypes of same species.
Enteric fever: It is a clinical syndrome characterized by fever, headache, cough, splenomegaly & leucopenia)