Pacific Science, Volume 48, Numbers 1-4, 1994

48: Index - Pacific Science

Sat, 01 Jan 1994 00:00:00 GMT

Contribution to the Marine Algal Flora of San Felix Island, Desventuradas Archipelago, Chile

Meneses, I; Hoffmann, AJ — Sat, 01 Oct 1994 00:00:00 GMT

Only 12 species of marine algae were known until now from the Desventuradas Archipelago. A recent collection added 10 species yielding a total of six Chlorophyta, nine Phaeophyta, and seven Rhodophyta. Only one species, Padina tristromatica Levring, is endemic. More than half of the representatives are in common with the flora of the Juan Fernandez Archipelago, but only five species are also found on the continental coasts of Chile and Peru.

Flavonoids and Condensed Tannins from Leaves of Hawaiian Vaccinium reticulatum and V. calycinum (Ericaceae)

Bohm, Bruce A; Koupai-Abyazani, Mohammed R — Sat, 01 Oct 1994 00:00:00 GMT

The flavonoids and condensed tannins of Hawaiian Vaccinium reticulatum Smith and V. calycinum Smith have been isolated and their structures determined. Flavonoids present in both species were quercetin, quercetin-3- 0-glucoside, quercetin-3-0-galactoside, quercetin-3-0-methyl ether, isorhamnetin, and (-)-epicatechin. The condensed tannin contained procyanidin units with cis stereochemistry only. Extension and terminal units, and number-average molecular weight of the polymer were determined. A large quantity of neochlorogenic acid (a caffeic acid derivative) was also detected. The phenolic compounds of V reticulatum from a population on Mauna Kea and two populations near K11auea, both on the island of Hawai'i, and from one population of V calycinum on Kaua'i were qualitatively identical. The high degree of similarity supports the view that these species are closely related. It is suggested that the phenolic chemistry of the species may have been fixed in the progenitor of the Hawaiian Vaccinium.

Effects of Decreased Salinity on Expulsion of Zooxanthellae in the Symbiotic Sea Anemone Anthopleura elegantissima

Engebretson, Hilary; Martin, Karen LM — Sat, 01 Oct 1994 00:00:00 GMT

Many natural conditions cause expulsion of zooxanthellae from corals and sea anemones. Recent studies have focused on causes and mechanisms of this release. We examined an incidence of bleaching in a field population of the sea anemone Anthopleura elegantissima (Brandt). Our data suggest that expulsion of zooxanthellae was caused by reduced salinity from freshwater runoff after heavy rainfall. In the laboratory, A. elegantissima expelled zooxanthellae in quantities directly correlated with strength and duration of exposure to hyposalinity. The mechanism of release appears to be rupture of the host cell, followed by accumulation of clumps of zooxanthellae that are then expelled from the coelenteron. A. elegantissima has little or no ability to osmoregulate the water in its coelenteron, and internal salinity drops rapidly with external salinity reduction.

The Caridea (Decapoda) Collected by the Mid-Pacific Mountains Expedition, 1968

Allen, JA; Butler, TH — Sat, 01 Oct 1994 00:00:00 GMT

Thirty-three species of caridean decapods have been identified from samples taken from the guyots and their vicinity, a little-sampled region of the mid-Pacific Ocean. Considering the oligotrophic character of the environment, a remarkably diverse collection has been collected. For the most part the species are mesopelagic and bathypelagic and have a widespread, if not cosmopolitan, distribution. Nevertheless, for many species these records extend their distribution much farther north and east in the Pacific than was previously known. The few epibenthic species present are more circumscribed in their distribution. Two of these were found to be previously undescribed and are described here.

Deep-sea Benthic Fish of the Hawaiian Archipelago, Cross Seamount, and Johnston Atoll

Chave, EH; Mundy, BC — Sat, 01 Oct 1994 00:00:00 GMT

More than 250 benthic fish taxa were photographed and videotaped by Hawaii Undersea Research Laboratory submersibles at depths between 40 and 2000 m in the Hawaiian Archipelago, Johnston Atoll, and Cross Seamount. Most of the 213 identified fish species occurred close to hard substrates with holes, ledges, or caves. Twenty-two species (notably the larger sharks, lutjanids, and carangids) are cosmopolitan. Seventy-six species are restricted to various Indo-Pacific areas, 64 in the Pacific, and 51 in the Hawaiian Archipelago including Cross Seamount and Johnston Atoll. There is a rapid decrease in the number of species from 200 to 400 m depth. One hundred eight species were seen 20 m deeper than previously reported. Eleven of the deeper-dwelling animals were found 20 m shallower than previously recorded. Faunal zones were not recognized at any depth. Species newly recorded in Hawai'i include Bathypterois grallator (Goode & Bean), Bodianus cylindriatus (Tanaka), Centrophorus cf. granulosus (Bloch & Schneider), Chaunax fimbriatus Hilgendorf, Caelorinchus spilonotus Sazonov & Iwamoto, Notocanthus sp., Paratrachichthys prosthemius Jordan & Fowler, Prognathodes guezei (Mauge & Bauchot), and Sladenia remiger Smith & Radcliffe. New species collected and reported elsewhere are Centrodraco rubellus Fricke et al., Epigonus glossodontus Gon, Owstonia sp., and Pseudanthiasfucinus (Randall & Ralston). Caelorinchus sp. 2 and Callanthias sp. are probably undescribed. It appears that the Hawaiian deep-sea fish fauna has multiple origins and affinities with many regions.

The Terrestrial Herpetofauna of the Ile des Pins, New Caledonia

Bauer, Aaron M; Sadlier, Ross A — Sat, 01 Oct 1994 00:00:00 GMT

The herpetofauna of the Ile des Pins, New Caledonia, is documented on the basis of 269 specimens representing 14 species. Included among new material collected by the authors are all but one of the seven taxa previously reported for the island. The fauna is a subset of that of the New Caledonian mainland, but a lack of elevational and habitat diversity has resulted in a relatively depauperate assemblage. Most of the species are endemic to the New Caledonian region, although several pan-Pacific geckos are also present. The scincid lizard Marmorosphax euryotis (Werner), previously regarded as rare, was found to be extremely abundant in rain forest on a pavement of raised reef. This species shares sexual dichromatism with its congener, but unlike M. tricolor (Bavay) it is apparently oviparous. The status of specimens of M. euryotis from the New Caledonian mainland remains unclear.

Subsistence Harvest of Birds, Fruit Bats, and Other Game in American Samoa, 1990-1991

Craig, Peter; Morrell, Tom E; So'oto, Kiso — Sat, 01 Oct 1994 00:00:00 GMT

Terrestrial birds and large pteropodid fruit bats are hunted year-round for subsistence in American Samoa. To determine harvest levels, 13-18% of the hunters on the main island of Tutuila were interviewed at 3-month intervals in 1990-1991. A high opportunistic harvest occurred after extensive habitat damage caused by a hurricane in February 1990. Adjusting for this factor, we estimated an annual take of 2100-4200 Pacific pigeons (Ducula pacifica Gmelin), 500-1000 purple-capped fruit doves (Ptilinopus porphyraceus Temminck), 500-1600 fruit bats (Pteropus tonganus Quoy & Gaimard and P. samoensis Peale, species combined), and small numbers of other species. Even this adjusted harvest rate is extremely high compared with current population sizes of game animals, which are at low levels due to adverse impacts from three hurricanes in the past 5 yr and subsequent opportunistic hunting. For example, after the hurricane in 1990, more bats were harvested than remain alive today. Consequently, a 3-yr ban on all hunting was enacted, but the situation remains critical because hunting restrictions are neither well known nor enforced.

Type Specimens of Hawaiian Birds Named by Sanford Ballard Dole

Olson, Storrs L — Sat, 01 Oct 1994 00:00:00 GMT

Sanford B. Dole described five nominal new taxa of Hawaiian birds in 1878, but because several of these names were quickly synonymized, their probable type specimens have been overlooked. Holotypes are here identified for Accipiter hawaii Dole (=Buteo solitarius Peale), Drepanis rosea Dole (=Vestiaria coccinea [Forster]), and D. aurea Dole (=Loxops coccineus [Gmelin]). The five specimens of Pennula millei Dole (=Porzana sandwichensis millsi [Dole]) have equal status as syntypes. Of the two supposed syntypes of Fringilla anna Dole (= Ciridops anna [Dole]), only one matches the original description and this is here considered to be the holotype.

A Specimen of Nuku pu'u (Aves: Drepanidini: Hemignathus lucidus) from the Island of Hawai'i

Olson, Storrs L; James, Helen F — Sat, 01 Oct 1994 00:00:00 GMT

A specimen of Nuku pu'u (Hemignathus lucidus Lichtenstein), collected by the U.S. Exploring Expedition in 1840 or 1841, is shown to have come from the island of Hawai'i. This is the first specimen evidence of the species for that island and the first evidence of probable sympatry of H. lucidus with the 'Akia pola'au (H. wilsoni Rothschild). Skull morphology provides additional evidence that these two species do not constitute a superspecies.

48:4 Table of Contents - Pacific Science

Sat, 01 Oct 1994 00:00:00 GMT

Ratio of Energy and Nutrient Fluxes Regulates Symbiosis between Zooxanthellae and Corals

Dubinsky, Z; Jokiel, PL — Fri, 01 Jul 1994 00:00:00 GMT

Ambient irradiance levels determine the rate of carbon influx into zooxanthellae at any given time, and thereby the energy available for the whole coral symbiotic association. Long-term photoacclimation of zooxanthellae to the time-averaged light regime at which the host coral grows results in optimization of light harvesting and utilization. Under high irradiance light harvesting is reduced, thereby avoiding photodynamic damage, whereas under low light, photon capture and quantum yield are maximized. Most of the photosynthate produced by the algae is respired. However, the capability of the zooxanthellae and the coral to retain carbon beyond that required to meet their respiratory needs depends on the availability of the commonly limiting nutrients, nitrogen and phosphorus. Therefore, the ratio of the flux of these nutrients into the colony to that of the photosynthetically driven carbon flux will regulate the growth of the zooxanthellae and of the animal. Nutrients acquired by predation of the coral on zooplankton are available first to the animal, whereas those absorbed by the zooxanthellae from seawater as inorganic compounds lead first to growth of the algae.

Resource Partitioning by Reef Corals as Determined from Stable Isotope Composition II. 15N of Zooxanthellae and Animal Tissue versus Depth

Muscatine, L; Kaplan, IR — Fri, 01 Jul 1994 00:00:00 GMT

The pattern of resource partitioning versus depth for corals collected in February, 1983, from Jamaica was investigated by analyzing their stable nitrogen isotope composition. Observations were made on isolated zooxanthellae and corresponding algae-free animal tissue from nine species of symbiotic corals at four depths over a 50-m bathymetric range, and from a nonsymbiotic coral at 1 m. 5 15N values versus depth ranged from +3.54 to -2.15 %0 for zooxanthellae and from +4.71 to +0.23 %0 for animal tissue. In those species that occurred over a 30- to 50-m depth range, both animal tissue and zooxanthellae tended to be depleted in 15N as depth increased to 30 m. In a few species animal tissue was enriched in 15N from 30 to 50 m. Depletion of 15N in zooxanthellae with increasing depth may be the result of depth-dependent differences in their nitrogen-specific growth rates. Animal tissue was consistently more depleted in 15N than for the nonsymbiotic coral Tubastrea coccinea (Ellis) at the same depth, but it was still slightly more enriched in 15N than corresponding zooxanthellae in 16 of 25 paired samples. The latter trend was not correlated with depth. A comparison of 5 13C and 5 15 N for zooxanthellae and animal tissue over 50 m revealed a tendency toward depletion of heavy isotopes as depth increases. Increased carbon fixation appears to be accompanied by decreased nitrogen fractionation.

Effects of Water Velocity on Respiration, Calcification, and Ammonium Uptake of a Porites compressa Community

Atkinson, MJ; Kotler, E; Newton, P — Fri, 01 Jul 1994 00:00:00 GMT

Colonies of Porites compressa Dana were placed in a 10-m-long flume to form a community of coral. Ammonium uptake (N uptake) rate, respiration rate, and calcification rate were measured at different water velocities, ranging from 1 to 57 cm sec-1. N uptake was proportional to concentration from 20 to 0.15 uM N. The first-order rate constant for N uptake varied from 6.8 to 15.6 day-1, only an average of 2.1 times over a l0-fold change in water velocity. First-order rate constants for respiration were less than those for N uptake and ranged from 4.8 to 6.6 day-1. Respiration rate and calcification rate were not correlated with water velocity. The relative turnover of N compared with oxygen (O2) indicates that 94-98% of N flux must be retained within this coral community.

Effect of Ammonium-supplemented Seawater on Glutamine Synthetase and Glutamate Dehydrogenase Activities in Host Tissue and Zooxanthellae of Pocillopora damicornis and on Ammonium Uptake Rates of the Zooxanthellae

Yellowlees, D; Rees, TAV; Fitt, WK — Fri, 01 Jul 1994 00:00:00 GMT

Host glutamine synthetase activity decreases in Pocillopora damicornis (Linnaeus) following exposure of the coral to seawater containing elevated ammonium (20 uM). Zooxanthellae isolated from these corals exhibited lower ammonium uptake capacity and glutamine synthetase activity compared with those from the control corals. Ammonium concentration of the surrounding seawater had no effect on the NADPH-dependent glutamate dehydrogenase activity in the host.

Effect of Ammonium Enrichment on Respiration, Zooxanthellar Densities, and Pigment Concentrations in Two Species of Hawaiian Corals

Stambler, Noga; Cox, Evelyn F; Vago, Razi — Fri, 01 Jul 1994 00:00:00 GMT

Small branch tips or "nubbins" of two species of Hawaiian corals, Pocillopora damicornis (Linnaeus) and Montipora verrucosa Vaughan, were exposed to four ammonium concentrations, ammonium-stripped < 2 uM), ambient (~2 uM), and two enriched (20 uM and 50 uM) in microcosm tanks. Nubbins represent replicates of a single coral colony. We examined the effect of ammonium enrichment on zooxanthellar densities, pigment concentrations, and respiration rates of the nubbins. Nubbins of both P. damicornis and M. verrucosa showed a trend of increased pigment concentration with elevated ammonium concentration. Pocillopora damicornis increased from 9.3 ug chlorophyll a cm-2 in the ammonium-stripped treatment to 24.8 ug cm-2 in the 50-uM ammonium treatment. Similarly, M. verrucosa increased from 1.9 to 19.4 ug chlorophyll a cm-2. There were no significant differences in algal densities, pigment concentrations per cell, pigment ratios, or respiration rates.

Effect of Ammonium Enrichment on Animal and Algal Biomass of the Coral Pocillopora damicornis

Muller-Parker, G; McCloskey, LR; Hoegh-Guldberg, O; McAuley, PJ — Fri, 01 Jul 1994 00:00:00 GMT

Algal and animal biomass parameters of colonies of the Pacific coral Pocillopora damicornis (Linnaeus) were measured as a function of time of exposure to elevated concentrations of seawater ammonium (20 and 50 uM [(NH4)2S04]) ranging from 2 to 8 weeks. Areal concentrations of zooxanthellae, chlorophyll, and protein increased with 20 uM ammonium addition. During the 8-week period of exposure to 20 uM ammonium, the population density of zooxanthellae increased from 3.5 to 7.5 x 105 cells cm-2, chlorophyll a content of zooxanthellae increased from 5.7 to 8.6 pg, and animal protein concentration doubled (from 0.74 to 1.38 mg cm-2). These data indicate that both the coral animal and the zooxanthellae respond to the addition of exogenous dissolved inorganic nitrogen provided as 20 uM ammonium. Growth of the symbiotic association in response to the addition of 20 uM ammonium adds further evidence to support the argument that growth of tropical symbioses is limited by the availability of nitrogen. However, the coral response is likely to depend on the concentration of ammonium provided, because the biomass parameters of corals held at 50 uM ammonium did not change significantly with time of exposure to the added nutrient.

Population Dynamics of Symbiotic Zooxanthellae in the Coral Pocillopora damicornis Exposed to Elevated Ammonium [(NH4)2 SO4] Concentrations

Hoegh-Guldberg, Ove — Fri, 01 Jul 1994 00:00:00 GMT

Division synchrony and growth rate of symbiotic zooxanthellae was investigated for populations living in colonies of the reef-building coral Pocillopora damicornis (Linnaeus) exposed to different concentrations of ammonium [(NH4)2S04] in seawater. Presence of low concentrations of ammonium (0.2 uM) did not affect (compared with corals growing in ammoniumstripped seawater) either division synchrony or growth rate. Exposure to higher concentrations of ammonium (20 or 50 uM), however, affected the population dynamics of the zooxanthellae residing in P. damicornis. Zooxanthellae in corals exposed to 20 uM ammonium had mitotic indices (percentage of total cells dividing) that were two to three times higher than mitotic indices of zooxanthellae in control (0.2 uM) corals. Although division of zooxanthellae was still phased in corals exposed to 20 uM ammonium, there were many more cells dividing out of phase compared with control corals. Division of zooxanthellae in corals exposed to 50 uM was not phased. Calculated growth rates of zooxanthellae exposed to 20 or 50 uM ammonium were higher than those representative of zooxanthellae living in control corals, although growth rate of both carbon and nitrogen pools was lower in 50 uM as compared with 20 uM ammonium. These data support the conclusion that the population dynamics of symbiotic zooxanthellae within P. damicornis are affected by concentrations of ammonium in seawater that are equal to or higher than 20 uM and that 50 uM ammonium concentrations may be toxic to some extent. These data taken in isolation, however, do not constitute an effective test of the hypothesis that zooxanthellae are limited by the supply of ammonium under ambient conditions and further emphasize the importance of enrichment studies concentrating on growth and nitrogen incorporation rates measured for the entire symbiotic association.

Effect of Exogenous Nitrogen Levels on Ultrastructure of Zooxanthellae from the Hermatypic Coral Pocillopora damicornis

Berner, Tamar; Izhaki, Ido — Fri, 01 Jul 1994 00:00:00 GMT

Branches of the hermatypic coral Pocillopora damicornis (Linnaeus) were exposed for 2, 4, 6, and 8 weeks to ammonium concentrations of < 1 uM (nutrient-stripped), 2 uM (seawater as a control), 20 uM, and 50 uM (enriched), after which their symbiotic zooxanthellae were examined for changes in their ultrastructure. No significant differences among treatments were detected in cell diameter or in relative volume of any of the cellular organelles of zooxanthellae subjected to the various nitrogen levels. The surface density of thylakoids was higher in cells from the elevated-nitrogen treatments. However, there was a significant increase in accumulation of starch grains and lipid droplets in zooxanthellae in corals maintained in unenriched and nutrient-stripped seawater, occupying about 15% of the cell volume. Storage of these N-free compounds showed that under N-limited conditions photosynthate cannot be used as carbon skeletons in synthesis of amino and nucleic acids, both required for cell doubling. We believe that our results further demonstrate the uncoupling of photosynthesis from population growth under C : N ratios deviating from those needed to support balanced growth.

Amino Acid Content of Zooxanthellae Freshly Isolated from Pocillopora damicornis

McAuley, PJ — Fri, 01 Jul 1994 00:00:00 GMT

Total amino-N content and glutamine to glutamate ratios (gln: glu) were determined in zooxanthellae freshly isolated from colonies of the coral Pocillopora damicornis (Linnaeus) incubated in ambient seawater or in seawater supplemented with ammonium to give a final concentration of 20 or 50 uM. Addition of ammonium did not change total amino-N content but did increase gln: glu from 0.25 to 0.47-0.48, suggesting that ammonium was directly utilized by the symbiotic zooxanthellae. Gln: glu in zooxanthellae from corals maintained in seawater "stripped" of ammonium fell to 0.18. Sizes of pools of most free amino acids in zooxanthellae from P. damicornis were roughly two to five times those of zooxanthellae from the temperate sea anenome Anemonia viridis, but the latter, which is not believed to be N-limited, exhibited higher gln: glu ratios. These data indicate that gln: glu is a sensitive measure of the response of symbiotic zooxanthellae to exogenous dissolved nitrogen, but despite an increase in gln: glu when seawater is supplemented with ammonium, it cannot be concluded that individual zooxanthellae are normally N-limited.