Molecular systematics, zoogeography, and evolutionary ecology of the Atlantic parrotfish genus Sparisoma

Parrotfishes of the genus Sparisoma (Scaridae) are ecologically important t ropical reef fishes restricted to the Atlantic Ocean. We investigated phylo genetic relationships among the eight extant species within this genus usin g mitochondrially encoded 12S and 16S ribosomal genes. Our molecular data s upport the view that (i) Sparisoma originated similar to 14-35 million year s ago (mya), probably in the tropical western Atlantic, off Brazil; (ii) th ere have been at least four discrete bouts of cladogenesis within the genus , with the most recent one (similar to 2.8-5.6 mya) involving four events i n both the east and the west Atlantic and across the Atlantic; and (iii) th e genus invaded the eastern Atlantic on two different occasions, probably b y at least two different routes. The data also offer support for Bellwood's ideas concerning the evolutionary changes in adult feeding patterns and ha bitat use within Scarids. Specifically, they support the evolutionary posit ion of the ecological traits of Sparisoma as intermediate within the family . (C) 2000 Academic Press.