Morphology of Luvarus imperialis (Luvaridae), with a Phylogenetic Analysis of the Acanthuroidei (Pisces)

Tyler, James C, G. David Johnson, Izumi Nakamura, and Bruce B. Collette. Morphology of Luvarus imperialis (Luvaridae), with a Phylogenetic Analysis of the Acanthuroidei (Pisces). Smithsonian Contributions to Zoology, number 485,78 pages, 50 figures, 1989.—The osteology of the rarely collected epipelagic fish Luvarus imperialis Rafinesque, the louvar, is redescribed, based for the first time on cleared and stained specimens of juveniles and young adults, as well as on dried skeletons of larger adults. Knowledge of the structure of fossil luvarids, from their first occurrence in the upper Paleocene to a very well-preserved specimen from the lower Eocene, is reviewed and their status re-evaluated. Earlier comparative anatomical studies are reviewed in historical perspective with regard to previously proposed relationships. It has been postulated most frequently that Luvarus is related to carangoid or scombroid fishes, the latter hypothesis having been the most widely accepted. With cladistic methodology and with much additional detailed information on the osteology and larval morphology of Luvarus and other groups, the carangoid and scombroid hypotheses are refuted. Luvarus is actually a highly specialized pelagic member of the typically reef-associated Acanthuroidei, the surgeon fishes and their allies. Scatophagids and ephippidids, respectively, are the first and second outgroups for the Acanthuroidei. Anatomical diagnoses of all acanthuroid genera are given. A cladistic analysis of the intra-relationships of the Acanthuroidei, based on 90 characters encompassing both larval and adult morphology, provides a highly corroborated hypothesis indicating the following phyletic sequence: Siganidae—Luvaridae—Zanclidac—Acanthuridae. OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SERIES COVER DESIGN: The coral Montastrea cavernosa (Linnaeus). Library of Congress Cataloging in Publication Data Morphology of Luvarus imperialis (Luvaridae), with a phylogenetic analysis of the Acanthuroidea (Pisces) / James C. lyicr . . . [ct al.]. (Smithsonian contributions to zoology ; no. 485) Bibliography: p. 1. Louvar—Classification. 2. Louvar—Morphology. I. Tyler, James C, 1935. II. Series. QL1.S54 no. 485 [QL638.L95] 591 s-dc20 [597'.58] 89-600070