The monotypic sardines, Sardina and Sardinops: their taxonomy, distribution, stock structure, and zoogeography

Both genera are monotypic. Differences between populations of Sardinops in different current systems are not large enough to consider them distinct subspecies. Analysis of biochemical genetics information, fossil evidence, and present and paleoclimatic conditions suggests that Sardinops did not achieve its present distribution until the Pleistocene and that westward exchange of sardines via the northern and southern west wind drift regions is possible with present climatic conditions. Transequator exchange appears to be possible only during glacial maxima and only in the E tropical Pacific. -from Authors