Pacific Science Volume 47, Number 3, 1993

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Pacific Science is a quarterly publication devoted to the biological and physical sciences of the Pacific Region.


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Now showing 1 - 5 of 11
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    Elattostachys (Blume) Radlk. (Sapindaceae) in Fiji
    (University of Hawaii Press, 1993-07) Adema, Frits
    Elattostachys vitiensis Seemann ex Radlk. is separated from E. falcata (A. Gray) Radlk., as a distinct species. Elattostachysfalcata is reduced to E. apetala (Labill.) Radlk. A key to the species of Elattostachys (Blume) Radlk. in Fiji and some distributional notes are given.
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    New and Noteworthy Malesian Myrsinaceae, VI. Scherantha, a New Subgenus of Ardisia
    (University of Hawaii Press, 1993-07) Stone, Benjamin C.
    Eight species originally described in Ardisia Sw., plus a ninth species newly described here, are grouped together to compose a new subgenus, Scherantha, within the genus Ardisia. A key to the species, illustrations, descriptions, and a distribution map of the taxa are provided. The question of generic limits and the characterization of Ardisia, Tapeinosperma, and Discocalyx are addressed.
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    The Relationship between Shell Morphology and Microhabitat Flow in the Endemic Hawaiian Stream Limpet (Hihiwai), Neritina granosa (Prosobranchia: Neritidae)
    (University of Hawaii Press, 1993-07) Way, Carl M. ; Burky, Albert J. ; Lee, Michael T.
    The Hawaiian stream limpet, Neritina granosa Sowerby, has three shell morphologies: conic (smooth, narrow shell), intermediate (rugose, narrow shell), and winged (flattened, rugose, and flared shell margin). We studied the relationship between shell morphology and water flow in a laboratory flume and in populations from Palauhulu Stream, Maui. Winged morphs represented 82% of the population at the mouth below the terminal waterfall. At sites above the falls, conic and intermediate morphs dominated. Limpets from the mouth had significantly lower shell-length/shell-width and body-weight/shellweight ratios and occurred in areas of lower benthic and surface velocities than upstream populations. Field determinations of velocities (measured with a thermistor-based microcurrent meter) around individual N. granosa in the field that were oriented parallel to flow demonstrated that conic and intermediate morphs experienced significantly less drag than winged morphs; there was no significant effect when shells were oriented perpendicular to flow. In a laboratory flume, conic and intermediate shells oriented parallel to flow exhibited significantly greater lift and less drag than a winged morph. There was no significant difference in lift and drag for conic and winged morphs in a perpendicular orientation. Because field orientation of the three shell morphs is unpredictable, we hypothesize that microhabitat flow has little or no effect on the phenotypic expression of shell morphology in N. granosa. We feel that the transition between winged and conic/intermediate morphs in upstream populations is restricted by bioenergetic constraints on the partitioning of energy between the competing demands of shell and tissue growth.
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    Behavioral Basis of Depth Regulation in the First Zoeal Stage of the Pacific Shore Crab, Hemigrapsus oregonensis (Brachyura: Grapsidae)
    (University of Hawaii Press, 1993-07) Arana, Marielise ; Sulkin, Stephen
    The behavioral basis of depth regulation is determined for the first pelagic larval stage of the shore crab Hemigrapsus oregonensis Dana. Larvae are negatively buoyant, passively sinking at 0.79 em/sec in 25 parts per thousand (ppt) salinity (S) seawater and at 0.67 em/sec in 30 ppt S. At 30 ppt S, larvae are negatively geotactic and move upward. At 25 ppt S, larvae remain negatively geotactic, but a low level of locomotor activity results in net downward movement. Swimming speed is higher at 30 ppt S than at 25 ppt S; however, there is no response to incremental increases in hydrostatic pressure up to 0.8 atm at either salinity. Behavioral responses should promote upward migration of the hatching stage similar to the case with other intertidal crab species; however, low precision in depth regulation contrasts with results from other species.
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    The Herpetofauna of the Senkaku Group, Ryukyu Archipelago
    (University of Hawaii Press, 1993-07) Ota, Hidetoshi ; Sakaguchi, Noriaki ; Ikehara, Sadao ; Hikida, Tsutomu
    The herpetofauna of the Senkaku Group, western Ryukyus, was reviewed on the basis of recent fieldwork, as well as museum specimens and literature records. As a result, six species of reptiles were recorded from the islands. They are Gekko hokouensis Pope, Eumeces elegans Boulenger, Scincella sp., Ramphotyphlops braminus (Daudin), Elaphe carinata carinata (Gunther), and Dinodon rufozonatus rufozonatus (Cantor). No amphibian species were recorded. The herpetofauna of the Senkaku Group is distinct from that of other parts of the Ryukyu Archipelago and is more similar to that of Taiwan and eastern continental China. These conclusions conform with paleogeographical evidence indicating that most islands of the Senkaku Group and Taiwan were connected to the eastern margin of the continent during the most recent glacial period, when the remaining Ryukyu Islands were never connected by dry land with the continent.
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