Pacific Science, Volume 49, Numbers 1-4, 1995

Karyotype of a Ranid Frog, Platymantis pelewensis, from Belau, Micronesia, with Comments on Its Systematic Implications

Ota, Hidetoshi; Matsui, Masafumi — Sat, 01 Jul 1995 00:00:00 GMT

The karyotype of Platymantis pelewensis Peters, 1867, the only native, endemic amphibian in Belau, extremely isolated from other congeners, consisted of 2n = 22 homologous chromosomes largely forming a graded series. Of these, chromosomes of pairs 1, 5, 6, 8, 10, and 11 were metacentric; the remainder were submetacentric. Secondary constrictions were evident on shorter arms of pair 7. This karyotype is nearly identical with that of P. papuensis Meyer from New Guinea, but is distinct from two Philippine congeners hitherto karyotyped both in chromosome number and morphology. This suggests that the ancestral form of P. pelewensis dispersed from New Guinea or other Melanesian islands.

The Copepod Genus Herrmannella (Poecilostomatoida) Associated with Marine Bivalve Mollusks at Kodiak Island, Alaska

Humes, Arthur G — Sat, 01 Jul 1995 00:00:00 GMT

The sabelliphilid copepods Herrmannella kodiakensis Humes, n. sp., and H. saxidomi (Illg, 1949) are reported from the marine bivalve Saxidomus giganteus (Deshayes). The new species may be differentiated from its congeners by the shape of the genital double-somite in the female (with "shoulders"). Copepodids of both species were found in S. giganteus and Protothaca staminea (Conrad). These are the first records of Herrmannella in Alaska.

A Review of the Hawaiian Hydrophilidae (Coleoptera)

Hansen, Michael — Sat, 01 Jul 1995 00:00:00 GMT

The species of Hydrophilidae occurring in the Hawaiian Islands are reviewed, with all genera and species keyed and briefly diagnosed. Six adventive species are reported for the first time from Hawaii: Coelostoma segne Balfour-Browne, Coelofletium exstriatum (Orchymont), Noteropagus obliquus Orchymont, Cercyon laminatus Sharp, Paroosternum horni (Orchymont), and Oosternum costatum Sharp. Of the 21 hydrophilids now known from the Islands, two are endemic, one is certainly indigenous, three are possibly indigenous, four are purposely introduced, and 11 are adventive.

Comparison of Water Quality and Reef Coral Mortality and Growth in Southeastern Kane'ohe Bay, O'ahu, Hawai'i, 1990 to 1992, with Conditions before Sewage Diversion

Coles, Stephen L; Ruddy, Lara — Sat, 01 Jul 1995 00:00:00 GMT

Growth and mortality of the three dominant coral species occurring in Kane'ohe Bay were determined for four periods from November 1991 to January 1993 at four stations in the bay's southeast basin. Twelve water quality parameters were monitored biweekly to monthly at these stations from November 1991 to August 1992. Both water quality measurements and coral survival and growth indicated considerable improvement to conditions that prevailed when treated sewage was discharged into this area of Kane'ohe Bay. Mean concentrations for orthophosphate, nitrite + nitrate, ammonia, and chlorophyll a, and mean values for light extinction and sedimentation were significantly less than those measured during time of sewage discharge in 19761977. Means of all of these except orthophosphate were not significantly different from means measured in 1978-1979 during the first year after sewage diversion. Mean orthophosphate concentration was approximately double the mean of the first year after diversion, and this increase may relate to increased abundances of the green macroalgae Dictyosphaeria cavernosa (Forskal) Boergesen that have been observed in this section of the bay in recent years. Montipora verrucosa (Lamarck) survived and grew well throughout the study period at all four stations, including stations in areas where rapid mortality and minimal growth occurred for this species in 1969-1971. The other two species, Porites compressa Dana and Pocillopora damicornis (Linnaeus), showed different survival and growth patterns according to station location. Most rapid mortality and lowest growth generally occurred for P. compressa at the station most affected by land runoff in the southernmost section of the bay. However, the major cause of early mortality and poor growth of Porites compressa at that location was the nudibranch Phestilla sibogae (Bergh), which rapidly consumed tissues of corals transplanted to that station, suggesting that predators that control P. sibogae parasitism elsewhere in the bay are absent from that area. Pocillopora damicornis survival and growth declined at all stations throughout the study, and this species may have been affected by fish predation. Growth of M. verrucosa and P. damicornis showed significant positive relationships with water turbidity values within a range of up to ca. 1.0 NTU.

Scleractinian Corals of Kuwait

Hodgson, G; Carpenter, K — Sat, 01 Jul 1995 00:00:00 GMT

A survey was made of the coral reefs of Kuwait to compile a species list of scleractinian corals. Twenty-eight hermatypic and six ahermatypic coral species are listed in systematic order, and a brief description is provided for each. A new species of Acropora is described. The Kuwait fauna is a small subset of the over 500 Indo-Pacific species. Several species show a higher degree of intraspecific variation than they exhibit in other locations. A range extension is reported for Acanthastrea maxima Sheppard & Salm, previously recorded from Oman (north and south coasts). A common species in the Arabian Gulf, Porites compressa Dana, has a disjunct distribution; it has not been found in the western Pacific, but occurs in the Red Sea, northern Indian Ocean, and Hawai'i. It is possible that the Gulf is one of the few places where Siderastrea and Pseudosiderastrea co-occur.

Rediscovery of Labordia triflora (Loganiaceae)

Motley, Timothy J — Sat, 01 Jul 1995 00:00:00 GMT

Labordia triflora Hillebr. is resurrected as a species distinct from L. tinifolia A. Gray based on its rediscovery on the island of Moloka'i in the Hawaiian Islands. It differs from L. tinifolia in its scandent habit, cordate leaf base, shorter petioles, slightly larger flowers and fruits, and fewer flowers per inflorescence on pistillate plants. Labordia triflora is endemic to Moloka'i, whereas L. tinifolia occurs on all major islands in the archipelago. The two taxa maintain allopatric populations on Moloka'i that are isolated by the physical and spatial barriers of a mountain range. Distinct morphology and allopatric distributions of the two taxa support resurrection of L. triflora as a separate species.

Effects of Extreme Drought on Vegetation of a Lava Flow on Mauna Loa, Hawai'i

Lohse, Kathleen A; Nullet, Dennis; Vitousek, Peter M — Sat, 01 Jul 1995 00:00:00 GMT

Effects of an extreme drought were examined along an elevational gradient on Mauna Loa Volcano, Hawai'i. The composition, vigor, and survivorship of plants were examined on a 2400-yr-old pahoehoe lava flow at three elevations: 1755,2000, and 2195 m above sea level. Three plant species, Coprosma ernodeoides A. Gray, Styphelia tameiameiae (Cham. & ScWechtend.) F. v. Muell., and Vaccinium reticulatum Sm., were encountered most frequently at the three sites. Greatest mortality occurred at the site at 2000 m elevation, where the drought caused a shift from a slight excess of precipitation over evaporation to a large excess of evaporation. Occasional severe droughts may play an important part in shaping primary succession in this region.

Factors Affecting Seed Germination of the Mauna Kea Silversword in Hawai'i

Walker, Lawrence R; Powell, Elizabeth Ann — Sat, 01 Jul 1995 00:00:00 GMT

The Mauna Kea silversword, Argyroxiphium sandwicense DC, is endemic to the slopes of Mauna Kea on the island of Hawai'i. Once abundant, it is now reduced to a total of less than 500 individuals. We examined germination of silversword seeds subjected to various experimental and field conditions. Under experimental conditions, germination was optimal in moist, shady environments. Removal of the pericarp greatly enhanced germination, but cold and heat pretreatments did not alter germination. Germination of field-collected seeds was highest for seeds < 2 yr old and for seeds collected from flower stalks. The ability to germinate was much lower for seeds collected from on or under the soil surface. In mesic environments, grasses competed with silversword seedlings. We suggest that seed germination and early seedling establishment are major obstacles to reestablishment of the Mauna Kea silversword.

49:3 Table of Contents - Pacific Science

Sat, 01 Jul 1995 00:00:00 GMT

Callidictyon abyssorum, gen. et sp. nov. (Rhodophyta), A New Deep-water Net-forming Alga from Hawai'i

Norris, James N; Abbott, Isabella A; Agegian, Catherine R — Sat, 01 Apr 1995 00:00:00 GMT

Callidictyon abyssorum, gen. et sp. nov., an unusual, net-forming red alga, is described from deep-water Pacific collections made from the research submersible Makati'i at 80-m depths on Penguin Bank, off the island of Moloka'i, Hawai'i. Though no reproductive structures were found, the new genus shares vegetative similarities with three tribes of the Ceramiaceae. The vegetative structure of C. abyssorum is similar to that of genera of the tribe Antithamnieae in having: (1) distinct basal cells on all primary lateral branches that are isodiametric and smaller than other cells of the primary laterals; (2) a central axis that is prostrate except for the portions near the apices of branches; and (3) axes that are completely without cortication. Some characters of C. abyssorum also suggest affinities to genera of the Callithamnieae, including: (1) the oblique apical cell division resulting in a strictly alternate branching pattern; (2) the absence of gland cells; and, (3) the presence of short, branching rhizoids on the basal cells of the primary lateral branches and long slender rhizoids on the main axial cells. Finally, the regularly alternate branching pattern, blunt apices, formation of anastomoses, and different .types of rhizoidal filaments, all characteristics of C. abyssorum, are also features present in members of the Compsothamnieae. Based on vegetative features, Callidictyon is tentatively placed in the Ceramiaceae until reproductive structures are found.

Vesicular-arbuscular Mycorrhizal Inoculation of Hawaiian Plants: A Conservation Technique for Endangered Tropical Species

Koske, RE; Gemma, JN — Sat, 01 Apr 1995 00:00:00 GMT

Forty species of plants (including 28 species endemic to the Hawaiian Islands) were evaluated in the greenhouse for their response to inoculation with the vesicular-arbuscular mycorrhizal fungus Glomus intraradices Schenck & Smith. Seedlings, cuttings, and established plants were inoculated. Several kinds of growth media were used. Increased growth and survival most frequently occurred when plants were grown in a gravel or fine sand medium that included calcined clay (up to 50% by volume) or sphagnum peat (up to 20%). Significant increases in height, weight, leaf number and size, and survival were noted in 10 of 14 species of seedlings grown in media in which peat content was 20% or less. Mycorrhizae were only rarely present in the noninoculated plants except for plants grown from cuttings. The latter routinely formed mycorrhizae in the absence of added inoculum. Addition of mycorrhizal fungi to potting mixes appears to have value as a conservation technique for some plants that are difficult to propagate.

Mycorrhizae in Hawaiian Epiphytes

Gemma, JN; Koske, RE — Sat, 01 Apr 1995 00:00:00 GMT

In surveys in the Hawaiian Islands, mycorrhizae occurred frequently in epiphytic, nonorchidaceous angiosperms and pteridophytes. Both vesicular-arbuscular (VA) and ericoid mycorrhizae were present in epiphytes growing 1-3 m above the forest floor on dead and living tree trunks and on living tree ferns in montane wet forest sites. All eight angiosperm species were mycorrhizal, and 13 of 22 pteridophytes possessed VA mycorrhizae. The high frequency of mycorrhizae in epiphytic species suggests that propagules of mycorrhizal fungi routinely are dispersed to these microsites. Possible means of dispersal are discussed.

Notes on Ceramium (Rhodophyta: Ceramiales) from the Hawaiian Islands

Meneses, Isabel — Sat, 01 Apr 1995 00:00:00 GMT

Ceramium is widely distributed and recorded from the coasts of the North Pacific Ocean. Thus, it is not surprising to find new species and new records of this genus among the numerous islands spread in this oceanic region. Extensive examination of material collected around O'ahu and other Hawaiian Islands has yielded two new records: Ceramium aduncum Nakamura (previously known from Japan), Ceramium clarionensis Setchell & Gardner (previously recorded for the Pacific coast of Mexico), and a new species, Ceramium cingulum Meneses.

Latitudinal Differences between Palau and Yap in Coral Reproductive Synchrony

Kenyon, Jean C — Sat, 01 Apr 1995 00:00:00 GMT

Twenty-seven species of coral were examined for reproductive activity in Palau during late spring and early summer 1993, and 10 species in Yap during the last week of May 1993. Thirteen species in Palau were gravid, and six were observed spawning during the week following Mayor June full moon. Spawning occurs over a minimum of 4 months in Palau. By contrast, all 10 coral species sampled in Yap, 420 km to the northeast, were well synchronized for a mass spawning event after June full moon. Intra- and interspecific spawning at equatorial latitudes is less tightly synchronized than at higher latitudes in the central Pacific. Opportunities for hybridization are a function, in part, of interspecific spawning synchrony. If hybridization serves as a mechanism for speciation in corals, then regions characterized by multispecies spawning events are more likely to serve as sites of speciation than those where spawning is more asynchronous.

Aspects of the Natural History of Pelagic Cephalopods of the Hawaiian Mesopelagic-Boundary Region

Young, Richard Edward — Sat, 01 Apr 1995 00:00:00 GMT

Pelagic cephalopods of the mesopelagic-boundary region in Hawai'i have proven difficult to sample but seem to occupy a variety of habitats within this zone. Abralia trigonura Berry inhabits the zone only as adults; A. astrosticta Berry may inhabit the inner boundary zone, and Pterygioteuthis giardi Fischer appears to be a facultative inhabitant. Three other mesopelagic species, Liocranchia reinhardti (Steenstrup), Chiroteuthis imperator Chun, and Iridoteuthis iris (Berry), are probable inhabitants; the latter two are suspected to be nonvertical migrants. The mesopelagic-boundary region also contains a variety of other pelagic cephalopods. Some are transients, common species of the mesopelagic zone in offshore waters such as Abraliopsis spp., neritic species such as Euprymna scolopes Berry, and oceanic epipelagic species such as Tremoctopus violaceus Chiaie and Argonauta argo Linnaeus. Others are apparently permanent but either epipelagic (Onychoteuthis sp. C) or demersal (Nototodarus hawaiiensis [Berry] and Haliphron atlanticus Steenstrup). Submersible observations show that Nototodarus hawaiiensis commonly "sits" on the bottom and Haliphron atlanticus broods its young in the manner of some pelagic octopods.

Larvae of Nearshore Fishes in Oceanic Waters of the Central Equatorial Pacific

Clarke, Thomas A — Sat, 01 Apr 1995 00:00:00 GMT

Larvae of 72 taxa of nearshore fishes were identified from midwater trawl samples taken in oceanic waters between Hawai'i and Tahiti. Catches of nearshore fish larvae and number of taxa caught declined with distance from the closest island. Most of the taxa were taken only within 300 km of the nearest island; only eight taxa were taken more than twice at greater distances. Highest catches were at stations close to major island groups, the Hawaiian or Society islands. Among stations closest to small isolated islands, densities were higher relative to distance from shore within the North Equatorial Countercurrent and the Equatorial Undercurrent; these strong eastward- flowing currents routinely transport larvae > 1000 km from likely sources upstream. Even in the zones of higher abundance, densities of nearshore larvae were much lower than in coastal waters, and adequate sampling in oceanic waters requires larger, faster nets than those typically used for ichthyoplankton studies.

A Small Collection of Skinks and Geckos from the Northwestern Islands of Fiji (Yasawa and Mamanuca Groups)

Shea, GM — Sat, 01 Apr 1995 00:00:00 GMT

Three species of geckos and six species of skinks are recorded from the small islands of the Yasawa and Mamanuca groups of Fiji. All are common, widespread species occurring throughout Fiji. Habitat and other ecological data for these species are provided.

49: Index - Pacific Science

Sun, 01 Jan 1995 00:00:00 GMT

Mercury Accumulation in Sediments of the Ala Wai Canal and in Soils and Stream Sediments of the Central Honolulu Watershed

Raine, Laurence M; Siegel, Barbara Z; McMurtry, Gary M — Sun, 01 Oct 1995 00:00:00 GMT

In this study we determined the historical trend of both natural and anthropogenic sources of mercury deposition as preserved in anoxic estuarine sediments of the Ala Wai Canal, an estuary situated within a heavily urbanized area of Honolulu. Analysis of sediments from the Ala Wai Canal revealed that the total mercury content is highest at the Ala Wai Yacht Harbor (0.054-2.810 ug/g) and decreases exponentially toward the most distal portion of the canal (0.009-0.237 ug/g). In contrast, the mercury content of soil and stream samples taken from the central Honolulu watershed ranges from only 0.001 to 0.058 ug/g. This pattern suggests tidal transport of mercury into the canal from the Ala Wai Yacht Harbor. A chronological analysis of core samples shows a peak in mercury concentrations in the late 1950s, which corresponds to the use of antifouling paints on boats in the harbor and is the probable source of the majority of the mercury found in the Ala Wai Canal. High mercury accumulation ends in the early 1970s in two of the cores investigated, suggesting that antifouling paint-based accumulation ceased rapidly after the U.S. Environmental Protection Agency (EPA) ban. An exception is noted in a comparatively smaller peak coincident with 1986, the last year of a 3-yr intense fire-fountaining period of the ongoing Pu'u '0'o eruption of nearby Kilauea Volcano.

Isotopic Clues to Sources of Natural and Anthropogenic Lead in Sediments and Soils from O'ahu, Hawai'i

Spencer, Khalil J; De Carlo, Eric H; McMurtry, Gary M — Sun, 01 Oct 1995 00:00:00 GMT

Stable Pb isotopes, Pb elemental concentrations, and, for some samples, Nd and Sr isotopes and concentrations have been analyzed on soils and on stream and estuarine sediments to evaluate the provenance of major inputs of Pb to the O'ahu, Hawai'i, environment. Core samples from the Ala Wai Canal, a major estuary draining urban Honolulu, preserve a historical record of anthropogenic lead input that peaked during the 1970s, the period of heaviest leaded-gas usage in Hawai'i. The timing of the Pb concentration peak and the simultaneous rise in Zn and Cd concentrations, two elements used in tire vulcanization, strongly suggest that the source of this Pb was tetraethyl Pb used in leaded gasoline. The changing Pb isotopic composition in these sediments reflects changing sources of ore from which tetraethyllead was produced. These isotopic signatures can be used to fingerprint anthropogenic Pb elsewhere on O'ahu. Although leaded gasoline has been phased out of production in the United States and in many other countries, elevated amounts of lead continue to deposit from the Ala Wai Canal's watershed. Sediment samples from Manoa Stream, a principal tributary, suggest that relatively uncontaminated sediments are eroded from its headwaters while a source (or sources) of lead continues to discharge into the stream as it nears the south end of Manoa Valley. The isotopic composition of this lead is similar to that measured in recently deposited sediments cored from the Ala Wai Canal. An atmospheric dust-enriched soil collected on the island of Hawai'i contains elevated Pb concentrations (55 ppm) and a Pb isotopic composition similar to North Pacific pelagic sediment. In addition, this sample contains unradiogenic Nd (E = -6) and radiogenic Sr (87Sr/86Sr = 0.722527) confirming an old, continentally derived provenance. Soils collected in Ha'ikii Valley, a windward O'ahu valley subject to high rainfall, contain variable Pb concentrations and Sr, Nd, and Pb isotopes trending toward the isotopic composition of the dust-enriched sample. This confirms that the Ha'ikii Valley soils contain an aerosol component. Soils enriched in this component could have natural lead concentrations higher than soils made up solely of weathered Hawaiian rocks. Hawai'i's soils and sediments have naturally derived variations in Pb concentration that are caused by differences in provenance and degree of weathering. Superimposed on this natural concentration variation is a variable anthropogenic signal. These variations should be factored into environmental monitoring programs.