A Phylogeny of the Spiny-Rayed Fish

Phylogeny and tempo of diversification in the superradiation of spiny-rayed fishes

Authors:

1. Thomas J. Neara,1,
2. Alex Dornburga,
3. Ron I. Eytana,
4. Benjamin P. Keckb,
5. W. Leo Smithc,
6. Kristen L. Kuhna,
7. Jon A. Moored,
8. Samantha A. Pricee,
9. Frank T. Burbrinkf,
10. Matt Friedmang, and
11. Peter C. Wainwrighte

Affiliations:

a. Department of Ecology and Evolutionary Biology and Peabody Museum of Natural History, Yale University, New Haven, CT 06520;

b. Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996;

c. Division of Fishes, The Field Museum, Chicago, IL 60605;

d. Wilkes Honors College and Harbor Branch Oceanographic Institution, Florida Atlantic University, Jupiter, FL 33458;

e. Department of Evolution and Ecology, University of California, Davis, CA 95616;

f. Biology Department, College of Staten Island/City University of New York, Staten Island, NY 10314; and

g. Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, United Kingdom

Abstract:

Spiny-rayed fishes, or acanthomorphs, comprise nearly one-third of all living vertebrates. Despite their dominant role in aquatic ecosystems, the evolutionary history and tempo of acanthomorph diversification is poorly understood. We investigate the pattern of lineage diversification in acanthomorphs by using a well-resolved time-calibrated phylogeny inferred from a nuclear gene supermatrix that includes 520 acanthomorph species and 37 fossil age constraints. This phylogeny provides resolution for what has been classically referred to as the “bush at the top” of the teleost tree, and indicates acanthomorphs originated in the Early Cretaceous. Paleontological evidence suggests acanthomorphs exhibit a pulse of morphological diversification following the end Cretaceous mass extinction; however, the role of this event on the accumulation of living acanthomorph diversity remains unclear. Lineage diversification rates through time exhibit no shifts associated with the end Cretaceous mass extinction, but there is a global decrease in lineage diversification rates 50 Ma that occurs during a period when morphological disparity among fossil acanthomorphs increases sharply. Analysis of clade-specific shifts in diversification rates reveal that the hyperdiversity of living acanthomorphs is highlighted by several rapidly radiating lineages including tunas, gobies, blennies, snailfishes, and Afro-American cichlids. These lineages with high diversification rates are not associated with a single habitat type, such as coral reefs, indicating there is no single explanation for the success of acanthomorphs, as exceptional bouts of diversification have occurred across a wide array of marine and freshwater habitats.