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Pre‐adaptive plasticity in atherinids and the estuarine seat of teleost evolution
Author(s) -
Bamber R. N.,
Henderson P. A.
Publication year - 1988
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/j.1095-8649.1988.tb05554.x
Subject(s) - biology , estuary , generalist and specialist species , intraspecific competition , genetic algorithm , phenotypic plasticity , pelagic zone , habitat , ecology , range (aeronautics) , ecological niche , fishery , materials science , composite material
With the aid of models and selected examples, an analysis of speciation within the family Atherinidae is presented. This is a large family of pelagic fish, many members of which look strikingly similar. They are primarily a marine coastal group, favouring sheltered estuaries and lagoons, although in some regions they have invaded fresh waters. Many atherinids show a high degree of intraspecific morphological variability which can be linked to their estuarine habitat. It is argued that estuarine and lagoonal environments are physically highly variable and this has acted to select for generalist genotypes able to adjust their morphology, physiology and behaviour to a wide range of conditions. Such plasticity pre‐adapts atherinids to invade and rapidly speciate in fresh waters containing vacant niches. Examples of such invasions and speciation are presented, and the rate of evolution discussed. The selective forces acting on atherinids should be common to other fish groups, suggesting that many freshwater fish may have estuarine ancestors. The influence of estuaries in evolution may be out of all proportion to their size.