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Title: Semelparous  
Author: World Heritage Encyclopedia
Language: English
Subject: Salmon run, Evolution of ageing
Publisher: World Heritage Encyclopedia


Semelparity and iteroparity refer to the reproductive strategy of an organism. A species is considered semelparous if it is characterized by a single reproductive episode before death, and iteroparous if it is characterized by multiple reproductive cycles over the course of its lifetime. Some plant scientists use the parallel terms monocarpy and polycarpy. (See also plietesials.)


This distinction is also related to the difference between annual and perennial plants. An annual is a plant that completes its life cycle in a single season, and is usually semelparous. Perennials live for more than one season and are usually (but not always) iteroparous.[1]



The word semelparity was coined by evolutionary biologist Lamont Cole,[2] and comes from the Latin semel 'once, a single time' and pario 'to beget'. Semelparity is also known as "big bang" reproduction, since the single reproductive event of semelparous organisms is usually large as well as fatal.[3] A classic example of a semelparous organism is Pacific salmon (Oncorhynchus spp.), which lives for many years in the ocean before swimming to the freshwater stream of its birth, spawning, and dying. Other semelparous animals include many insects, including some species of butterflies, cicadas, and mayflies, many arachnids, and some molluscs such as some species of squid and octopus.

Semelparity also occurs in smelt and capelin, but is very rare in vertebrates other than bony fish. In amphibians, it is known only among some Hyla frogs including the gladiator frog;[4] in reptiles only a few lizards such as Labord's chameleon of southwestern Madagascar[5] and Sceloporus bicanthalis of the high mountains of Mexico;[6] and among mammals only in a few didelphid and dasyurid marsupials.[7] Annual plants, including all grain crops and most domestic vegetables, are semelparous. Long-lived semelparous plants include century plant (agave), Lobelia telekii, and some species of bamboo.[8]



Semelparity vs. iteroparity



Models based on non-linear trade-offs



Bet-hedging models


Cole's Paradox and demographic models



In his analysis, Cole assumed that there was no mortality of individuals of the iteroparous species, even seedlings. Twenty years later, Charnov and Schaffer [12] showed that reasonable differences in adult and juvenile mortality yield much more reasonable costs of semelparity, essentially solving Cole's paradox. An even more general demographic model was produced by Young.[13]


r/K selection

Semelparity can be a characteristic of r strategists, and iteroparity a characteristic of K strategists.[16]

See also


Further reading

  • (peer-reviewed) Nature Education Knowledge entry on Semelparity
