The Indo-West Pacific blenniid fish genus Istiblennius reappraised : a revision of Istiblennius, Blenniella, and Paralticus, new genus

Springer, Victor G. , and Jeffrey T. Williams. The Indo-West Pacific Blenniid Fish Genus Istiblennius Reappraised: A Revision of htiblennius, Blenniella, and Paralticus, New Genus. Smithsonian Contributions to Zoology, number 565, 193 pages, 73 figures, 45 tables, 1994. —Istiblennius Whitley, as most recently defined (Smith-Vaniz and Springer, 1971), comprises 2 monophyletic groups of species, which we recognize as separate genera, Blenniella Reid (9 species) and Istiblennius (14 species). A cladistic analysis supports the hypothesis that Blenniella and Istiblennius form a clade. The 14 species of Istiblennius include 2 new species: /. pox, from southernmost Red Sea, Persian Gulf, Gulf of Oman, and /. spilotus, from most of East African coast, Comoro Islands, Madagascar, Gulf of Oman, and Pakistan. A monotypic new genus, Paralticus, is described for Salarias amboninensis Bleeker, which had been assigned most recently (Smith-Vaniz and Springer, 1971) to Praealticus Schultz and Chapman. Although superficially similar to Istiblennius species, P. amboinensis is a member of a clade that also comprises Praealticus, Alticus, and Andamia. Most of the species we revise exhibit statistically significant meristic sexual dimorphism, as well as noticeable geographic variation. All species are illustrated, including both sexes, individual and geographic variants, and ophioblennius stage prejuveniles (for all 5 species for which these stages are known). Distribution maps for all species are presented. Cladistic analyses are given for a subset of the genera of the tribe Salariini, to which the 3 genera we revise belong, and for the species of Blenniella and Istiblennius. The generic level analysis corroborates a major portion of the analysis proposed by Williams (1990). Because of character variability, we consider the results of the generic analyses highly tentative. Discussions of the biogeography of the genera and species are presented. The Philippine Islands are noted as a general area of endemism for fishes and an explanation is proposed. The pattern of east-west disjunctly distributed species, or sister species, first noted by Springer and Williams (1990), is modified slightly and shown to be common one for fishes. The western portion of the disjunct distributions appears to be restricted to the western Indian Ocean south of the equator and west of the mid-Indian Ocean Ridge. Some species that are not disjunctly distributed are limited in distribution to the same area of the Indian Ocean as the western disjunct portions of other species. The area of disjunction almost always includes, at least, the Gulf of Thailand and the southern half of the South China Sea. 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 Springer, Victor Gruschka, 1928The Indo-West Pacific blenniid fish genus Istiblennius reppraised: a revision of Istiblennius, Blenniella, and Paralticus, new genus / Victor G. Springer and Jeffrey T. Williams p. cm. —(Smithsonian contributions to zoology ; no. 565) Includes bibliographical references. 1. Istiblennius. 2. Blenniella. 3. Paralticus. 4. Blenniidae-Classification. I.Williams, Jeffrey T. II. Title. III. Series Q11.S54 no. 565 [QL638.B6] 591 s—dc20 94-15323 [59T.58] CIP © The paper used in this publication meets the minimum requirements of the American National Standard for Permanence of Paper for Printed Library Materials Z39.48—1984.