Antidromous is a word that refers to a type of fish that migrates upstream to spawn. The spelling of this word is influenced by its Greek origin. The "anti-" prefix denotes opposite or against, while "dromous" means running or flowing. The pronunciation of this word is /ˌæntɪˈdroʊməs/, with stress on the second syllable. The correct spelling of this word can be confusing for some, but remembering its phonetic transcription can make it easier to use and understand.
Antidromous is an adjective used to describe the migratory behavior of certain animals, particularly fish, that swim against the prevailing current or flow of water during certain stages of their life cycle. This term is commonly associated with fish species that undergo a unique form of migration, often referred to as "upstream" migration.
During the antidromous migration, these fish swim from the sea or ocean, where they typically spend most of their adult life, against the current, upstream into rivers or freshwater habitats. This migration pattern is notably different from the typical "anadromous" migration, in which fish swim from freshwater rivers to the sea.
Antidromous fish species are usually motivated to migrate upstream in order to spawn or reproduce in their original freshwater habitats. After hatching from eggs, juveniles often drift downstream, flowing with the current until they reach the ocean or sea, where they will grow and mature. When they reach sexual maturity, antidromous fish return to their natal rivers or freshwater systems to lay their eggs and repeat the cycle.
Salmon and certain species of eels are well-known examples of antidromous fish. Their remarkable ability to navigate and persevere against strong currents and obstacles while migrating upstream is an essential part of their life cycle, vital for their survival as a species.
The word "antidromous" is composed of two Greek roots: "anti", meaning "against" or "opposite", and "dromos", meaning "running" or "course". When combined, "antidromous" literally means "running against" or "swimming against the current". This term is specifically used to describe certain migratory behavior of fish, such as salmon, which swim against the natural flow of water to return to their original breeding grounds.