Pacific Science Volume 53, Number 2, 1999

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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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    Description of a New Allopatric Sibling Species of Hawaiian Picture-Winged Drosophila
    (University of Hawai'i Press, 1999-04) Kaneshiro, Kenneth Y. ; Kambysellis, Michael P.
    A new picture-winged Hawaiian Drosophila species from the islands of Kaua'i and O'ahu that is morphologically indistinguishable from Drosophila grimshawi Oldenberg from the Maui Nui islands is described, based on differentiation in ecological, behavioral, cytological, and molecular characters as well as ultrastructural features of the chorion. The new species, D. craddockae, and D. grimshawi represent the first clear case of an allopatric sibling species pair among Hawaiian Drosophilidae (i.e., there is strong evidence for a profound set of intrinsic, genetically determined differences that are not easily diagnosable by the usual morphological methods). Ecologically, D. craddockae is a strict specialist, with oviposition restricted to the decaying bark of Wikstroemia. Drosophila grimshawi, on the other hand, is a generalist that breeds in the decaying parts of 10 families of plants. Data from cytological, behavioral, and molecular analyses are consistent with the geological evidence that species on the older islands are usually more ancestral than those that evolved on the younger islands. Thus, although long-standing ecological theory states that specialization is a derived condition, the biological and genetic evidence all indicate that specialism in D. craddockae is the ancestral condition and that generalism evolved in D. grimshawi on Maui Nui as a derived trait.
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    Review of the Dragonets (Pisces: Callionymidae) of the Hawaiian Islands, with Descriptions of Two New Species
    (University of Hawai'i Press, 1999-04) Randall, John E.
    Eight species of dragonets, family Callionymidae, are reported from the Hawaiian Islands: Callionymus caeruleonotatus Gilbert, known from 12 specimens taken by trawling in 43-252 m, the male with the two middle caudal rays greatly prolonged; C. comptus, a new species described from nine Hawaiian specimens, 15.0-30.3 mm SL, characterized by eight soft dorsal and seven anal rays, usually a small spinule on lower side of preopercular spine (in addition to the antrorse spine at the base), and a color pattern of a narrow midlateral yellow stripe edged in pale blue spots and overlaid with six brownish orange blotches; C. decoratus (Gilbert), known to 208 mm SL, the male with a caudal fin that may exceed the standard length; Draculo pogognathus (Gosline) from shallow water in sand, unique in lacking a membrane connecting the inner pelvic ray to the pectoral-fin base and in having a fringe of papillae on the lower lip; Synchiropus corallinus (Gilbert) with a small cirrus on the eye, previously classified in Callionymus, Paradiplogrammus, and Minisynchiropus, also known from Japan and New Caledonia; S. kinmeiensis (Nakabo, Yamamoto & Chen), a red species represented by 186 Hawaiian specimens, 56-136 mm SL, trawled from 220-532 m (previously misidentified as the Japanese species S. altivelis); S. rosulentus, a small species (largest, 21.5 mm SL) described as new from 20 specimens from the Hawaiian Islands and Johnston Island (it is one of a complex of six allopatric species, the males of which have the first dorsal fin about twice the height of the second dorsal and two small elliptical jet black spots above the base of each pelvic fin); and S. rubrovinctus Gilbert, known from three male specimens, 14.2-19.5 mm SL, trawled from 51.5-79 m between Maui and Uina'i, and one female specimen, 21.5 mm SL, collected in a tide pool at Izu Peninsula, Japan; both sexes are characterized by a long filamentous first dorsal spine and three broad red bars dorsally on the body.
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    Observations of a Probable Hybrid Angelfish of the Genus Holacanthus from the Sea of Cortez, Mexico
    (University of Hawai'i Press, 1999-04) Sala, Enric ; Aburto-Oropeza, Octavio ; Arreola-Robles, Jose L.
    A probable new hybrid angelfish was observed in Cabo San Lucas, Baja California, Mexico. Body coloration was olive brown, with a dark orange area behind the head and a vertical white bar posterior to the pectoral fin. The caudal fin was bright orange red, and pelvic fins were pale yellow. Dorsal and anal fin margins were bright blue and pointed. All characters support the hypothesis that the unidentified pomacanthid is a hybrid of Holacanthus passer and H. clarionensis, and we suggest a possible explanation for this interspecific hybridization.
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    Pocillopora inflata, A New Species of Scleractinian Coral (Cnidaria: Anthozoa) from the Tropical Eastern Pacific
    (University of Hawai'i Press, 1999-04) Glynn, Peter W.
    Pocillopora inflata, n. sp., a relatively rare zooxanthellate scleractinian coral, is described from live colonies collected in the Galapagos Islands (Ecuador) and from three additional localities in the tropical, far-eastern Pacific region. Distinguishing features are (1) swollen terminal or subterminal branches, (2) verrucae acute and few in number or absent, and (3) columellae prominent in calices at mid to lower branch levels. The swollen branches and acute verrucae serve to separate Pocillopora inflata from two morphologically similar species: Pocillopora diomedeae Vaughan from Easter Island and Pocillopora informis Dana from Hawai'i. Comparisons of the type colony with paratypes from the Galapagos Islands and elsewhere in the eastern Pacific revealed notable intraspecific variability in peripheral branch thickness and verrucae number and length. This new species is found at shallow depths (2-10 m), often intermixed with other species of Pocillopora. Where present at five survey sites in the Galapagos Islands, it made up from 2 to 17% of all species of pocilloporids combined, with population densities ranging from 0.2 to 2.5 colonies per hectare.
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    Occurrence of Indigenous Plant Species in a Middle-Elevation Melaleuca Plantation on O'ahu (Hawaiian Islands)
    (University of Hawai'i Press, 1999-04) Woodcock, D.W. ; Perry, J.L. ; Giambelluca, T.W.
    The occurrence of native species at a middle-elevation (265-290 m) site on the island of O'ahu is of interest because of the extremely disturbed character of the vegetation and paucity of native forest species in the vicinity and at these elevations generally. 'Ohi'a (Metrosideros polymorpha) and native shrubs are understory elements in a plantation of Melaleuca quinquenervia that was planted in the early 1930s. The relatively open character of the stand (light levels underneath the canopy 20-50% of incident radiation) may allow enough penetration of light to the subcanopy for native woody plants while excluding more light-demanding alien taxa. The variety of Metrosideros present is the smooth-leaved form (M polymorpha var. glaberrima) more prevalent in the later stages of succession. The findings presented here may be an example of a tree plantation acting to foster native species and promote forest regeneration, a phenomenon that has been reported in degraded lands elsewhere in the Tropics.
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    A Reassessment of Dubautia (Asteraceae: Heliantheae - Madiinae) on Kaua'i
    (University of Hawai'i Press, 1999-04) Carr, Gerald D.
    Aggressive botanical exploration of Kaua'i has yielded nearly 200 collections and two new species of Dubautia since the last monograph of the genus was published about a dozen years ago. This paper presents an updated key to the 13 species of Dubautia found on Kaua'i, summarizes and discusses the importance and systematic impact of recent collection data, and provides new maps to reflect the current knowledge of species distributions.
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    First Highly Stratified Prehistoric Vertebrate Sequence from the Galapagos Islands, Ecuador
    (University of Hawai'i Press, 1999-04) Steadman, David W. ; DeLeon, Valerie Burke
    We report an assemblage of ca. 6900 vertebrate fossils from a preliminary excavation at Barn Owl Cave, Isla Floreana, Galapagos Islands, Ecuador. Age of this stratified deposit ranges from historic times (less than 200 yr old) to the early Holocene (at least 8290 ± 70 radiocarbon years B.P., which equals 7485-7055 B.C.). Five of the 11 indigenous species identified thus far from the bone assemblage no longer occur on Floreana. Their extirpation is due to human influence over the past two centuries. The sedimentary and faunal compositions of the Barn Owl Cave bone deposit may reflect paleoclimatic changes, with relatively wet intervals indicated by darker, more clayey sediments and a relative scarcity of bones of the Floreana lava lizard (Micro/aphis grayii). Further excavation at Barn Owl Cave is likely to yield insights into the timing and extent of late Quaternary climatic and faunal changes in the Galapagos Islands.
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    53:2 Table of Contents - Pacific Science
    (University of Hawai'i Press, 1999-04)
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