The Significance of Body Size, Dispersal Potential, and Habitat for Rates of Morphological Evolution in Stomatopod Crustacea

Reaka, Marjorie L., and Raymond B. Manning. The Significance of Body Size, Dispersal Potential, and Habitat for Rates of Morphological Evolution in Stomatopod Crustacea. Smithsonian Contributions to Zoology, number 448, 46 pages, 11 tables, 1987.—This study reviews the world-wide distribution and status of all families and genera of stomatopod Crustacea, and tests a number of hypotheses about factors that alter rates of morphological evolution of stomatopods from the Atlanto-East Pacific region. The degree of morphological divergence of lineages among geographic subregions (East Pacific, West Atlantic, East Atlantic) and the incidence of local species radiation is both inversely and highly significantly related to species body size. Similarly, postlarval size and dispersal potential are significantly and inversely related to morphological divergence among subregions; local species multiplication is especially highly correlated with small postlarvae and restricted dispersal. Our data suggest that speciation may be higher for taxa inhabiting reef and rock substrates than level bottoms; these taxa also experience greater competition for resources and exhibit more complex behavior than those from level bottoms. However, other environmental attributes, such as depth, temperature, and latitude, were consistently unrelated to measures of divergence and speciation. Although further study is needed, extinctions appear to be more common in the gonodactyloids than in the lysiosquilloids or squilloids, in taxa with small postlarvae and restricted dispersal, in lineages inhabiting coral reefs compared to level bottoms, in tropical versus temperate latitudes, and in the East Atlantic followed by the East Pacific and then the West Atlantic geographic subregions. 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 ofCongress Cataloging in Publication Data Reaka, Marjorie L. The significance of body size, dispersal potential, and habitat for rates of morphological evolution in stomatopod Crustacea. (Smithsonian contributions to zoology ; no. 448) Bibliography: p. Includes index. Supt. of Docs, no.: SI 1.27 : 448 1. Stomatopoda—Morphology. 2. Stomatopoda—Evolution. 3. Crustacea—Morphology. 4. Crustacea— Evolution. 1. Manning, Raymond B., 1934-11. Title. Ill Series QLI.S54 no. 448 591s 86-600272 [QL444.M375] [595.3'82]