09 April 1993
Vol 260, Issue 5105

About The Cover

Fishes of the suborder Scombroidei, like this school of Euthynnus affinis in the Red Sea, are capable of endothermy. A molecular phylogeny of this suborder (which includes mackerels, bonitos, tunas, and bill-fishes) indicates that endothermy has evolved three times within Scombroidei. Comparison of endothermic scombroids with their closest living ectothermic relatives provides a further understanding of how endothermy evolved. See page 210 and the News story on page 160. [Photo: Jeffrey L. Rotman/Peter Arnold, Inc.]