Pacific Science 57, no. 1
The Butterflies of Pohnpei, Eastern Caroline Islands, Micronesia
Donald W. Buden and Jacqueline Y. Miller, pp. 1-8
Abstract: Fourteen species of butterflies are recorded from Pohnpei, Micronesia, seven for the first time. None is endemic to the island; all are widely distributed in the western Pacific, including parts of Indo-Australia, with many extending into or beyond southeastern Asia. A long history of plant introductions and agricultural experimentation may have facilitated dispersal of butterflies to the island and provided a broad selection of host plants for those arriving otherwise unassisted. At least one, and possibly two or more, unidentified species apparently confined to deep forest habitats were seen but not collected during this study. Compared with the local odonate fauna, the butterflies of Pohnpei differ in reaching their greatest abundance and species diversity in the lowlands, in lacking endemic species, and probably in having a higher turnover rate.
Occurrence of Hawksbill Turtles, Eretmochelys imbricata (Reptilia: Cheloniidae), near the Baja California Peninsula, México
Jeffrey A. Seminoff, Wallace J. Nichols, Antonio Resendiz, and Louise Brooks, pp. 9-16
Abstract: From 1997 to 2001 the occurrence of hawksbill turtles (Eretmochelys imbricata) was characterized at neritic foraging habitats along the Pacific coast of the Baja California Peninsula and in the Gulf of California, México, through in-water capture of live turtles and searches for dead carcasses. We recorded a total of 27 hawksbill turtles: 14 (four live-captured and 10 strandings [dead turtles]) along the Pacific coast of Baja California and 13 (seven live-captured and six strandings) in the Gulf of California. The range of straight carapace lengths for hawksbill turtles from the Pacific and the Gulf of California was 35.4 to 52.5 cm (mean = 42.5 cm) and 34.4 to 74.2 cm (mean = 48.0 cm), respectively. Although hawksbills are uncommon in coastal neritic habitats near Baja California, their continued presence indicates that this region should be included as a focus area for future conservation efforts.
An Update on Modes and Timing of Gamete and Planula Release in Hawaiian Scleractinian Corals with Implications for Conservation and Management
Steven P. Kolinski and Evelyn F. Cox, pp. 17-27
Abstract: Reproductive data for 24 of the 50 plus species of scleractinian corals in Hawai‘i are available. A majority of species (75%) are broadcast spawners, just over half (58%) of which are hermaphrodites. Peak reproduction of Hawaiian corals occurs during summer months, although reproduction continues year-round for some brooders. Timing, duration, mode, and location of reproductive processes have implications for disturbance management, assessment, and conservation of reef corals.
A New Species of Callulops (Anura: Microhylidae) from Papua New Guinea
Fred Kraus and Allen Allison, pp. 29-38
Abstract: We describe a new species of Callulops from the vicinity of Crater Mountain Biological Station in south-central Papua New Guinea. The species may be distinguished from its congeners by its unique dorsal color pattern, moderately expanded digital disks bearing circummarginal grooves, smooth skin, relatively long legs, and relatively short snout. The species is currently known only from the type locality, and its nearest relatives remain obscure.
Five Species of Parasitic Copepods (Siphonostomatoida: Pandaridae) from the Body Surface of a White Shark Captured in Morro Bay, California
George W. Benz, Henry F. Mollet, David A. Ebert, Corrine R. Davis, and Sean R. Van Sommeran, pp. 39-43
Abstract: Five pandarid (Copepoda) species, Dinemoura producta, D. latifolia, Echthrogaleus coleoptratus, Pandarus bicolor, and Achtheinus oblongus, were collected from the external body surface of a white shark, Carcharodon carcharias, taken from Morro Bay in the northeastern Pacific Ocean off central California. This is the first report of parasitic copepods collected from C. carcharias captured in the northeastern Pacific along the West Coast of North America. It is proposed that the species-rich infections of some white sharks may be the result of the wide wanderings of individual sharks through waters inhabited by other elasmobranchs.
A Survey of the Small Reef Fishes of Kane‘ohe Bay, O‘ahu, Hawaiian Islands
David W. Greenfield, pp. 45-76
Abstract: The small, sedentary fishes, many of which are cryptic, in Kane‘ohe Bay, O‘ahu, Hawaiian Islands, were surveyed based on 75 small rotenone stations from 10 different habitats. These stations resulted in a total of 192 species from 48 different families. An additional 10 other small species were recorded from the bay in other samples ancillary to this study for a total of 202 species from 49 families. Assemblage structure for specific taxa was investigated using detrended correspondence analysis. Only the following taxa demonstrated various levels of clustering of stations from specific habitats in ordination space: Blennioidei, Labridae, Apogonidae, Gobiidae, Serranidae, and Anguilliformes. When these taxa were combined into a single analysis the distinctiveness of sheltered patch reefs within the bay from all other habitats was reinforced. These findings support earlier conclusions based on studies in the Atlantic Ocean that a search for a single model to explain assemblage structure of coral-reef fishes is ill founded.
Chemical Indicators of Anthropogenic Nitrogen-Loading in Four Pacific Estuaries
Brian Fry, Arian Gace, and James W. McClelland, pp. 77-101
Abstract: Watershed inputs of anthropogenic nitrogen (N) are altering the trophic status of estuaries worldwide. In this study we compared two chemical approaches for assessing watershed N inputs to estuaries: (1) use of conventional nutrient concentration measurements, and (2) use of nitrogen isotope ([delta]15N) measurements in estuarine sediments and biota. Of special interest was testing whether [delta]15N assays were generally robust tracers of watershed N across different estuarine systems. Four Pacific estuaries were chosen for study at widely spaced intervals on the U.S. West Coast: Padilla Bay (northern Washington State), South Slough (southern Oregon), Elkhorn Slough (central California), and Tijuana River (southern California). These estuaries are part of the National Estuarine Research Reserve (NERR) system. They are relatively small and shallow, are well flushed by tides, and can receive substantial natural N-loading from seasonally upwelled offshore waters. Results showed that none of the estuaries was truly pristine, with high watershed DIN (dissolved inorganic nitrogen) concentrations >500 [mu] M especially in Elkhorn and Tijuana estuaries that respectively received high agricultural and sewage inputs. Nitrogen isotope assays failed to detect N-loading under conditions of very high ammonium inputs from sewage, but were otherwise useful indicators of estuarine N status in all four estuaries. Overall, using a combination of nutrient and isotope measurements was the best strategy for detecting watershed N-loading in these estuaries. The combination approach could be used to generate maps of low, medium, and high inputs to each of the four study estuaries. The N isotope measurements appear to be useful especially for tracing historical development of N-based eutrophication and for showing entry of pollutant N into local food webs.
Sieve Plates and Habitat Adaptation in the Foraminifer Planulina ornata
Johanna M. Resig and Craig R. Glenn, pp. 103-110
Abstract: Planulina ornata (d’Orbigny), a coarsely perforate species of foraminifera having a low trochospiral test was recovered attached to phosphatic hardgrounds from the lower oxygen-minimum zone off Peru. Above the base of individual pores are calcified, perforate sieve plates, the largest so far described. Structure of the pores suggests a possible association with mitochondria and respiratory function. These large pores may facilitate extraction of the severely limited amount of oxygen from the ambient bottom waters at that locale.
Pacific Science Assocation, pp. 111-115
Pacific Science 57, no. 2
Human Impacts on Fluxes of Nutrients and Sediment in Waimanalo Stream, O‘ahu, Hawaiian Islands
Edward A. Laws and Lisa Ferentinos, pp. 119-140
Abstract: Waimanalo Stream, on the windward side of the island of O‘ahu in the Hawaiian Islands, has been greatly altered by human activities. Native riparian vegetation has been removed along much of the course of the stream, and significant sections of the stream have been hardened to control flooding. Absence of shade from riparian vegetation has allowed California grass (Brachia mutica), wild sugarcane (Saccharum officinarum), and other vegetation to proliferate in the stream channel. Some reaches of the stream more closely resemble a wetland than a natural watercourse. During fair weather and moderate storms, this vegetation effectively traps sediment. During a year when rainfall was [nearly equal to] 40% below average, dissolved N and P accounted for most of the N and P transported by the stream. N and P content of the suspended solids was comparable with that of terrestrial organic matter, but with a slightly lower N/P ratio, probably due to the high iron content of Hawaiian soils. Concentration of suspended solids in the stream was only about 4% of the average concentration in fluvial systems that discharge to the ocean. Base flow accounted for about 32% of the P, 58% of the suspended solids, and 96% of the N transported by the stream. The very high contribution of base flow to the N flux was apparently related to contamination of shallow groundwater in the lower reach of one tributary, in which nitrate N concentrations during base flow were about 7 mg liter–1. Flux of N in the stream was comparable with the amount of N produced by livestock waste in this predominantly agricultural watershed. Cesspool seepage and/or leaching of N from animal waste into shallow groundwater and seepage of that groundwater into the stream may account for the anomalously high N loading to the stream. Absence of a similarly high P flux probably reflects the high iron content of Hawaiian soils, which effectively immobilize P in groundwater.
First Record of a Rhizosolenia debyana Bloom in the Gulf of California, México
Ismael Gárate-Lizárraga, David A. Siqueiros-Beltrones, and Verónica Maldonado-López, pp. 141-145
Abstract: A bloom of the diatom Rhizosolenia debyana H. Peragallo was observed in the southwestern Gulf of California. This bloom was estimated to be about 22 km long and represents the first record of this species for the area. Total abundance of R. debyana ranged from 2,576,000 to 3,684,000 cells liter–1. Chlorophyll a concentrations ranged from 17.15 to 41.45 mg/m3. Rhizosolenia debyana has a tropical and subtropical distribution.
Movement Patterns of Dark-Rumped Petrels and Newell’s Shearwaters on the Island of Hawai‘i
Robert H. Day, Brian A. Cooper, and Richard J. Blaha, pp. 147-159
Abstract: We studied movements and distribution and abundance of endangered Dark-rumped Petrels (‘Ua‘u; Pterodroma phaeopygia sandwichensis Ridgway) and threatened Newell’s Shearwaters (‘A‘o; Puffinus auricularis newelli Henshaw) on the island of Hawai‘i in May–June 2001 and 2002. We recorded radar targets of either species at 14 of the 18 sites but recorded no birds visually at any site. Movement rates of petrels and shearwaters were very low (0–3.2 targets/hr) over all except one of the sites (Waipi‘o Valley; 25.8 targets/hr). We saw radar targets moving from shortly after sunset throughout the rest of the sampling, suggesting that both petrels and shearwaters were present. The highest movement rates occurred 1–2 hr after sunset, when primarily Newell’s Shearwaters are flying. The timing of evening movements suggests that Dark-rumped Petrels fly over the northern and southern parts of the island and may dominate on Mauna Loa and Mauna Kea. In contrast, the timing suggests that Newell’s Shearwaters fly over essentially the entire island (except in the southwestern part, where no birds appear to occur), dominate numerically in the Kohala Mountains, and occur in low numbers on Mauna Loa, in the Puna District, and on the northern slopes of Mauna Kea. Evening flight directions were predominantly inland at all sites except four. The limited radar data suggest that a substantial population change did not occur in the Puna District from 1995 to 2001–2002.
Rediscovery of Blackburnia anomala (Blackburn) (Coleoptera: Carabidae), in East Maui, Hawai‘i after an 107-year Hiatus
D. A. Polhemus, Curtis P. Ewing, R. Takumi, and James K. Liebherr, pp. 161-166
Abstract: The highly distinctive and diverse, native Hawaiian carabid beetle fauna includes a suite of species not recently observed in nature. These are predominantly historical residents of the mesic Acacia koa forest formation. We report rediscovery of one of these species, Blackburnia anomala (Blackburn) (Coleoptera: Carabidae), in the shrubland formation near Paliku Cabin, and in koa forest of Kaupo Gap. Prior records of B. anomala are limited to the leeward edges of historical koa forest near Olinda, on the northwest slope of Haleakala. Rediscovery on the far southeastern side of Haleakala Crater in similar, though conserved habitats, suggests that other long-missing koa-associates may persist in similar situations on Haleakala.
Helminths of the Ezo Brown Frog, Rana pirica (Ranidae) from Hokkaido Island, Japan
Stephen R. Goldberg and Charles R. Bursey, pp. 167-169
Abstract: Rana pirica, endemic to Hokkaido Island, Japan, was examined for helminths. One species of Monogenea, Polystoma ozakii, two species of Nematoda, Oswaldocruzia socialis and Rhabdias nipponica, and one species of Acanthocephala, Acanthocephalus lucidus, were found. Rana pirica represents a new host record and Hokkaido Island a new locality record for O. socialis, R. nipponica and A. lucidus. None of the helminths found in this study are restricted to Hokkaido Island.
Wood Anatomy of Hawaiian and New Guinean Species of Tetramolopium (Asteraceae): Ecological and Systematic Aspects
Sherwin Carlquist and Timothy K. Lowrey, pp. 171-179
Abstract: Qualitative and quantitative features are reported for five Hawaiian and one New Guinean species of Tetramolopium. Tetramolopium humile differs from the other Hawaiian species in its numerous narrow vessels, numerous vasicentric tracheids, and wide rays. Although these features are adaptive in the dry alpine localities of T. humile, they would be adaptive also in the remaining species, which are from dry to moderately dry lowland localities. Thus, one can consider these features of T. humile as systematic indicators. The wood of T. pumilum (New Guinea) has distinctive wide, tall rays that may be related to the short stems in this species; T. pumilum has wood more mesomorphic than that of any of the Hawaiian species. Within Hawaiian Tetramolopium, wood anatomy correlates with dryness of habitat. The species of Tetramolopium studied have highly xeromorphic wood in comparison to woods of dicotyledons at large.
Phylogeny and Biogeography of Pacific Rubus subg. Idaeobatus (Rosaceae) Species: Investigating the Origin of the Endemic Hawaiian Raspberry R. macraei
Clifford W. Morden, Donald E. Gardner, and Dana A. Weniger, pp. 181-197
Abstract: The endemic Hawaiian raspberries, Rubus hawaiensis and R. macraei (both subg. Idaeobatus), had been thought to be closely related species until recent molecular studies demonstrated otherwise. These studies suggest that they are the products of separate colonizations to the Hawaiian islands. Affinities of R. hawaiensis to R. spectabilis of western North America were clearly confirmed. However, no clear relation to R. macraei has been published. This study was initiated to examine species of subg. Idaeobatus from the surrounding Pacific region as well as species from other subgenera to better evaluate biogeographic and phylogenetic affinities of R. macraei by means of chromosome analysis and molecular data using the chloroplast gene ndhF. Results show that R. macraei clusters in a clade with species of blackberries, subg. Rubus, and of these it is most closely linked to R. ursinus. Chromosomally, R. macraei is 2n = 6x = 42, a number that would be a new report for subg. Idaeobatus. However, polyploidy is common in subg. Rubus. Analyses indicate that R. macraei and R. hawaiensis are derived from separate colonizations from North America and that similarities between them are due to convergent evolutionx in the Hawaiian environment.
Morphological and Genetic Variation in the Endemic Seagrass Halophila hawaiiana (Hydrocharitaceae) in the Hawaiian Archipelago
Karla J. McDermid, Monica C. Gregoritza, Jason W. Reeves, and D. Wilson Freshwater, pp. 199-209
Abstract: The endemic seagrass, Halophila hawaiiana Doty and Stone, is found in discrete populations throughout the Hawaiian Archipelago. Morphological characteristics of plants from Midway Atoll, Pearl and Hermes Reef, Kaua‘i, O‘ahu, Moloka‘i, and Maui were measured and compared. Striking variation in leaf length, leaf width, leaf length to width ratio, and internode length was evident among the 18 collection sites sampled at depths ranging from 0.32 m to 18 m. DNA sequence analyses of a chloroplast-genome, single-base repeat locus in ramets from nine different collections found only two repeat haplotypes. Repeat haplotypes were fixed at all collection sites and for all islands except O‘ahu.
Charcoal Stratigraphies for Kaua‘i and the Timing of Human Arrival
Lida Pigott Burney and David A. Burney, pp. 211-226
Abstract: Evidence from microscopic charcoal particle stratigraphy is presented from nine locations distributed throughout Kaua‘i in the Hawaiian Islands, including windward and leeward coastal sites and interior bogs at elevations ranging up to 1220 m. The overall trends are comparable to those reported for other mesic tropical island areas lacking strong seasonality, beginning with a general dearth of charcoal in sediments that predate evidence for humans on the island, followed by an increase of an order of magnitude or more at a time that probably represents first human presence at the site. In most cases, this initial peak or plateau of increased charcoal from presumably anthropogenic sources is followed by a prehistoric decrease and a second peak after European contact. Charcoal evidence presented here suggests a human presence in leeward coastal areas beginning ca. 830 ± 50 yr BP (1050–1095, 1140–1280 cal yr AD). One windward site, Limahuli Bog, may show charcoal evidence for humans as early as 1470 ± 60 yr BP (440–670 cal yr AD), but resolution is poor in the upper part of this core. Charcoal and sedimentological evidence suggests that Hawaiians were constructing fishponds as early as about eight centuries ago, and that the massive stoneworks forming the Alekoko or Menehune Fishpond, probably the largest prehistoric stone structure in the Hawaiian Islands, may have been completed by 580 ± 30 yr BP (1305–1420 cal yr AD). Charcoal peaks in prehuman times, particularly at 3800 ± 40 yr BP (4080–4290 cal yr BP), may be associated with prolonged drought conditions. Charcoal particles are virtually absent from the late Pleistocene sediments collected from interior bogs.
Pacific Science Association, pp. 243
Pacific Science 57, no. 3
Pteridophytes of Moorea, French Polynesia, with a New Species, Tmesipteris gracilis (Psilotaceae)
A. G. Murdock and A. R. Smith, pp. 253-265
Abstract: We examined collections of pteridophytes from Moorea and others of the Society Islands, as well as literature relevant to the pteridophytes of Polynesia. This resulted in a list of species known to occur on Moorea, along with a list of species reported for Moorea but lacking voucher specimens, and a list of species perhaps to be found on Moorea based on collections from nearby Tahiti and adjacent islands in the archipelago, at suitable elevations. We include habitat, locality, and appropriate taxonomic commentary for each known species. A new species in the family Psilotaceae, Tmesipteris gracilis Chinnock, is described from the Society and Marquesas Islands. We also include a discussion of pteridophyte collection history on Moorea and biogeographic notes for species on the island.
The Liagoraceae (Rhodophyta: Nemaliales) of the Hawaiian Islands. 1: First Record of the Genus Gloiotrichus for Hawai‘i and the Pacific Ocean
John M. Huisman and Isabella A. Abbott, pp. 267-273
Abstract: Gloiotrichus fractalis Huisman & Kraft is documented for the first time from the island of Hawai‘i, Hawaiian Islands, which also represents the first record for the Pacific Ocean. The single specimen on which the record is based is 12 cm in height, extremely mucilaginous, with percurrent primary axes and irregularly arranged lateral branches. Carpogonial branches are borne on the basal one to three cells of cortical fascicles; when mature they are five to eight cells long and straight. Before fertilization cells of the carpogonial branch produce several lateral branches similar in morphology to cortical filaments. After presumed fertilization the zygote (= postfertilization carpogonium) divides transversely and gonimoblast initials are produced from both of the resultant cells. Mature carposporophytes are spherical, with terminal carposporangia and a fusion cell formed from the cells of the carpogonial branch and basal cells of lateral filaments. The Hawaiian specimen is identical in virtually all respects to those from the Indian Ocean type locality in the Houtman Abrolhos Islands of Western Australia.
New Records and Notes on Hawaiian Marine Benthic Chlorophyta, including Pseudochlorodesmis abbreviata (Gilbert), n. comb. (Udoteaceae) and Cladophora luxurians (Gilbert), n. comb. (Cladophoraceae)
Isabella A. Abbott and John M. Huisman, pp. 275-285
Abstract: Morphology, taxonomy, and nomenclature of three species of Hawaiian green algae (Chlorophyta) are examined. Udotea? abbreviata Gilbert is shown to be incorrectly placed in that genus and more appropriately allied to Pseudochlorodesmis. The complex nomenclatural relationships of Cladophora tildeniae Brand in Tilden, Cladophora tildeniae Brand, and Cladophora hawaiiana Tilden are described, with the latter deemed the appropriate name and Microdictyon japonicum var. laxum Gilbert regarded as a synonym. An examination of Cladophoropsis luxurians Gilbert has shown it to have delayed formation of transverse walls at the bases of lateral branches, a feature not consistent with inclusion in Cladophoropsis but rather with Cladophora. The new combinations Pseudochlorodesmis abbreviata (Gilbert) Abbott & Huisman and Cladophora luxurians (Gilbert) Abbott & Huisman are made, and nine species of marine benthic Chlorophyta are newly recorded for the Hawaiian Islands.
Marine Isopod Crustaceans from Easter Island
Brian Kensley, pp. 287-317
Abstract: Isopods from 29 shallow-water stations around Easter Island were identified. Thirteen species in three suborders are described as new: suborder Anthuridea, Mesanthura pascuaensis, Sauranthura rapanui, Califanthura dodecaseta, Paranthura nordenstami; suborder Asellota, Joeropsis acoloris, Joeropsis bicornis, Joeropsis limbatus, Joeropsis trilabes, Salvatiella islapascua, Uromunna biloba, Paramunna pellucida, Santia longisetae; suborder Flabellifera, Exosphaeroides quadricosta. Seven species were identified only to genus: Apanthura sp., Eisothistos sp., Carpias sp., Maresiella sp., Metacirolana sp., Munna sp., Panathura sp. The shallow-water marine isopods show an endemism of over 90%.
Natural Diet of Juvenile Abalone Haliotis fulgens and H. corrugata (Mollusca: Gastropoda) in Bahía Tortugas, Mexico
Sergio A. Guzmán del Próo, Elisa Serviere-Zaragoza, and David Siqueiros-Beltrones, pp. 319-324
Abstract: Diet of juvenile (10–100 mm in length) abalone (Haliotis fulgens and H. corrugata) in their natural environment was examined in specimens collected at Bahía Tortugas, Baja California Sur. Nine macroalgae species, one polychaete worm, one amphipod, one hydrozoan, and one sea grass were identified. A high percentage of stomachs analyzed were empty. In those with contents, Phyllospadix torreyi (Anthophyta), Laurencia sp., Gelidiales (Rhodophyta), and Phaeophyta (Dictyotales) were the most common items. Most specimens with macroalgal material came from depths in which H. fulgens (shallow) and H. corrugata (>6 m) are more abundant. Benthic diatoms were almost absent from ingested material.
Regressions of Length and Width to Predict Arthropod Biomass in the Hawaiian Islands
Daniel S. Gruner, pp. 325-336
Abstract: Biologists in many fields use published regression equations to predict biomass from simple linear body measurements. Power functions are used with arthropods, facilitating biomass estimation of a sample when destructive techniques are not feasible. Resulting predictive coefficients vary widely depending on region and taxa. There are no published biomass regressions for oceanic island fauna, despite the widely accepted conclusion that their arthropod assemblages are unusual in composition. I present a suite of general and taxonomically and morphologically restricted regression equations developed for arthropods in the Hawaiian Islands. General regression equations were hightly significant when only length was used to predict biomass, but fits were usually improved by including body width. In regressing restricted sets of taxa, the addition of width did little to improve the fit of the functions. Thus, the choice of regression equations involves a trade-off in taxonomic resolution: precise biomass estimates will come either from (1) low taxonomic resolution measured for both length and width, or (2) high taxonomic resolution measured only for body length. These equations have a high predictive capacity for a broad range of arthropod taxa common in the Hawaiian Islands and, in the absence of locally developed equations, the arthropods of other oceanic islands.
Pacific Science Association, pp. 337-341
Pacific Science 57, no. 4
Revegetation in Dead Dicranopteris (Gleicheniaceae) Fern Patches Associated with Hawaiian Rain Forests
Peter A. Follett, Puanani Anderson-Wong, M. Tracy Johnson, and Vincent P. Jones, pp. 347-357
Abstract: Dieback of Dicranopteris linearis (Burm. f.) Underwood on wet, open valley slopes and ridgelines of Maui, O‘ahu, and Kaua‘i has been attributed to feeding by the introduced leafhopper Sophonia rufofascia Kuoh & Kuoh. We studied early plant succession at a variety of low-elevation D. linearis dieback sites to assess the vulnerability of these disturbances to invasion by nonnative weeds. Dead patches of D. linearis were colonized by both native and alien plant species; the number and assemblage of colonizing plant species was site specific. Clidemia hirta (L.) D. Don and Nephrolepis multiflora (Roxb.) Jarrett ex C. Morton were the most common invasive species colonizing and spreading in dieback patches. Recolonization of dead patches by live D. linearis spreading from the margins was also common. In a simulated fern decomposition study, seedling germination increased as the depth of the thicket decreased. Fern dieback may enhance regeneration of the native tree Acacia koa A. Gray.
Importance of Benthic Prey for Fishes in Coral Reef–Associated Sediments
Ralph C. DeFelice and James D. Parrish, pp. 359-384
Abstract: The importance of open, sandy substrate adjacent to coral reefs as habitat and a food source for fishes has been little studied in most shallow tropical waters in the Pacific, including Hawai‘i. In this study, in Hanalei Bay, Hawai‘i, we identified and quantified the major invertebrate fauna (larger than 0.5 mm) in the well-characterized sands adjoining the shallow fringing reefs. Concurrently, we identified the fish species that seemed to make substantial use of these sand habitats, estimated their density there, sampled their gut contents to examine trophic links with the sand habitat, and made other observations and collections to determine the times, locations, and types of activity there. A variety of (mostly small) polychaetes were dominant in the sediments at most sampling stations, along with many small crustaceans (e.g., amphipods, isopods, ostracods, and small shrimps) and fair numbers of mollusks (especially bivalves) and small echinoids. Fish guts examined contained ~77% of the total number of benthic taxa collected, including nearly all those just listed. However, fish consumption was selective, and the larger shrimps, crabs, and small cryptic fishes were dominant in the diets of most of the numerous predator taxa. Diets of benthic-feeding fishes showed relatively low specific overlap. The fish fauna in this area included substrate-indifferent pelagics, species with various degrees of reef relatedness, reef-restricted species, and (at the other extreme) permanent cryptic sand dwellers. Data on occurrence and movements of fishes indicated that a band of sandy substrate several tens of meters wide next to the reef was an active area for fishes, and activity was considerably different at different times of day and for fish of different ages. These results imply an important trophic role for the benthos in these near-reef habitats in support of reef-associated fishes.
Nesting Behavior of Palila, as Assessed from Video Recordings
Megan E. Laut, Paul C. Banko, and Elizabeth M. Gray, pp. 385-392
Abstract: We quantified nesting behavior of Palila (Loxioides bailleui), an endangered Hawaiian honeycreeper, by recording at nests during three breeding seasons using a black-and-white video camera connected to a videocassette recorder. A total of seven nests was observed. We measured the following factors for daylight hours: percentage of time the female was on the nest (attendance), length of attendance bouts by the female, length of nest recesses, and adult provisioning rates. Comparisons were made between three stages of the 40-day nesting cycle: incubation (day 1–day 16), early nestling stage (day 17–day 30 [i.e., nestlings &Mac178; 14 days old]), and late nestling stage (day 31–day 40 [i.e., nestlings > 14 days old]). Of seven nests observed, four fledged at least one nestling and three failed. One of these failed nests was filmed being depredated by a feral cat (Felis catus). Female nest attendance was near 82% during the incubation stage and decreased to 21% as nestlings aged. We did not detect a difference in attendance bout length between stages of the nesting cycle. Mean length of nest recesses increased from 4.5 min during the incubation stage to over 45 min during the late nestling stage. Mean number of nest recesses per hour ranged from 1.6 to 2.0. Food was delivered to nestlings by adults an average of 1.8 times per hour for the early nestling stage and 1.5 times per hour during the late nestling stage and did not change over time. Characterization of parental behavior by video had similarities to but also key differences from findings taken from blind observations. Results from this study will facilitate greater understanding of Palila reproductive strategies.
Discovery of the Sea Grass Halophila decipiens (Hydrocharitaceae) in the Diet of the Hawaiian Green Turtle, Chelonia mydas
Dennis J. Russell, George H. Balazs, Ron C. Phillips, and Alan K. H. Kam, pp. 393-397
Abstract: The herbivorous Hawaiian green turtle (Chelonia mydas L.) has expanded its forage to include a newly reported sea grass species, Halophila decipiens Ostenfeld, that is closely related to the previously documented food item, Halophila hawaiiana Doty & Stone. Halophila decipiens was first reported in Hawai‘i in the literature in 2001, but our investigations have found it in reef specimens preserved from 1979 and in more recent samples from green turtle forestomachs. Its presence as a dietary item indicates that green turtles probably began utilizing this species after 1998. The status of H. decipiens as an indigenous species to Hawai‘i, its effects on turtle pastures, and the adjustment of feeding behavior of C. mydas to the presence of a species abundant and available as a food source are discussed.
The Odonata of Kosrae, Eastern Caroline Islands, Micronesia
Donald W. Buden and Dennis R. Paulson, pp. 399-407
Abstract: A recent collection of 69 specimens together with survey counts and incidental observations during June–July 2002 provide new information on the odonate fauna of Kosrae, Micronesia. The fauna comprises one zygopteran (Ischnura aurora) and six anisopterans. It appears to have remained stable with no known extinctions or colonizations over the past half century. The fauna is nearly a subset of that of Pohnpei and the islands to the west, and it comprises six widespread weedy species and one endemic, Hemicordulia erico. Upland aquatic habitats appear largely unexploited or underutilized by odonates, and the absence of any Teinobasis species on Kosrae is in marked contrast to the presence of six species on the nearest high island, Pohnpei.
Ants (Hymenoptera: Formicidae) of Samoa
James K. Wetterer and Donald L. Vargo, pp. 409-419
Abstract: The ants of Samoa have been well studied compared with those of other Pacific island groups. Using Wilson and Taylor’s (1967) specimen records and taxonomic analyses and Wilson and Hunt’s (1967) list of 61 ant species with reliable records from Samoa as a starting point, we added published, unpublished, and new records of ants collected in Samoa and updated taxonomy. We increased the list of ants from Samoa to 68 species. Of these 68 ant species, 12 species are known only from Samoa or from Samoa and one neighboring island group, 30 species appear to be broader-ranged Pacific natives, and 26 appear to be exotic to the Pacific region. The seven-species increase in the Samoan ant list resulted from the split of Pacific Tetramorium guineense into the exotic T. bicarinatum and the native T. insolens, new records of four exotic species (Cardiocondyla obscurior, Hypoponera opaciceps, Solenopsis geminata, and Tetramorium lanuginosum), and new records of two species of uncertain status (Tetramorium cf. grassii, tentatively considered a native Pacific species, and Monomorium sp., tentatively considered an endemic Samoan form).
Macroalgae from 23 Stream Segments in the Hawaiian Islands
Nanda R. Filkin, Alison R. Sherwood, and Morgan L. Vis, pp. 421-431
Abstract: Twenty-three stream segments (seven on O‘ahu, eight on Kaua‘i, and eight on Hawai‘i) were sampled for macroalgae in the Hawaiian Islands. Stream segments ranged greatly in size from 1.2 to 40 m in width. Water temperature was uniformly warm (17–24°C), but other chemical parameters differed from site to site (pH 5.5–8.9, specific conductance 20–200 µS · cm–1). Mean species richness per site was 3.9 with one to eight species collected per stream segment. Ninety populations of 42 infrageneric taxa were identified from the Cyanobacteria (19), Chlorophyta (17), Rhodophyta (3), and Chrysophyta (3). The most abundant taxa were Spirogyra sp. 1, Audouinella pygmaea, and Phormidium retzii. All three of these taxa are widespread among the Islands. Other species collected on all three islands were Cloniophora plumosa and Hildenbrandia angolensis. Eighteen taxa are new records for streams and 15 of these for aquatic habitats. Ten of the new records for the Hawaiian Islands were collected on Kaua‘i, six on O‘ahu, and one on Hawai‘i (two new records shared for Kaua‘i and O‘ahu). The large percentage (36%) of new taxa reported in this study suggests that more research is needed to fully catalog the Hawaiian stream macroalgal diversity. This study extends the number of micro- and macroalgal taxa known from streams in the Hawaiian Islands to 299 infrageneric taxa.
Variation in Structure of the Subcanopy Assemblage Associated with Southern California Populations of the Intertidal Rockweed Silvetia compressa (Fucales)
Stephanie A. Sapper and Steven N. Murray, pp. 433-462
Abstract: Variation in structure of the subcanopy communities associated with southern California Silvetia compressa ( J. Agardh) Serrão, Cho, Boo & Brawley populations was examined at eight sites, including four long-standing intertidal Marine Protected Areas (MPAs). Although sea temperature and salinity showed little variation, maximum wave force and sand influence differed significantly among sites. Seaweed and sessile macroinvertebrate cover and mobile macroinvertebrate densities were determined in 10 quadrats during both autumn 1995 and spring 1996. A total of 111 taxa was distinguished at the eight sites, including 47 macroalgae, 20 sessile macroinvertebrates, and 44 mobile macroinvertebrates; however, only a few species consistently dominated abundances in the subcanopy assemblage. Silvetia compressa cover varied significantly among sites during both sampling periods; cover was significantly greater at all but one site during the autumn. Morphologies of Silvetia compressa thalli were qualitatively similar except at Monarch Bay, where plants were the least densely aggregated and frond lengths were two to three times greater than at other sites. Seaweeds contributed 71.2% of the subcanopy cover averaged over all sites compared with 23.8% sessile macroinvertebrate cover; mobile invertebrate densities averaged 363.9 m–2 over all sites. The three most abundant seaweeds (Pseudolithoderma nigra, Pseudolithophyllum neofarlowii, and Corallina pinnatifolia/C. vancouveriensis) and macroinvertebrates (Phragmatopoma californica, Mytilus californianus, and Anthopleura elegantissima) accounted for approximately 67% and 20%, respectively, of total understory cover. The three most abundant mobile macroinvertebrates (Littorina scutulata, Lepidochitona hartwegii, and Macclintockia scabra/Lottia conus) accounted for nearly 60% of all mobile animals. An average of 27 macrophytes and sessile macroinvertebrates and 19 mobile macroinvertebratesoccurred at a site; site H’ diversity based on macrophyte and sessile macroinvertebrate cover averaged 1.91; mobile macroinvertebrate H’ diversity based on density averaged 2.03. Neither cluster analysis nor multidimensional scaling produced clear site patterns based on geographic location or sampling period; long-standing MPA sites did not form a distinct group and did not differ significantly in community structure from nonhistorical MPAs based on Analysis of Similarity (ANOSIM) tests. Communities representing autumn and spring were more closely associated with each other than with communities from other sites. Differences in community structure were detected among individual sites in all ANOSIM tests despite strong similarities in abundant taxa. ANOSIM tests also showed that understory communities differed between sampling periods, except for analyses based on cover in recently established MPAs. Significant differences in the cover and density of many abundant subcanopy populations also were found among sites using univariate statistical procedures. Only weak relationships could be established between variations in species types and environmental factors. These results suggest the importance of localized and stochastic histories in generating site variation among rockweedassociated populations and the difficulties in establishing post hoc relationships between environmental patterns and variations in species abundances.
Three New Species of Saccocirrus (Polychaeta: Saccocirridae) from Hawai‘i
J. H. Bailey-Brock, J. Dreyer, and R. E. Brock, pp. 463-478
Abstract: Three new species of saccocirrids from interstitial sand habitats off O‘ahu, Hawai‘i, are described. Two are from subtidal depths, 9–33 m, and the third is from the intertidal to 3.5 m deep on a fringing reef and at Hanauma Bay, the Marine Life Conservation District and public park. The two deeper-water species, Saccocirrus oahuensis, n. sp. and S. waianaensis, n. sp., have 76–119 and 157–210 segments, respectively; they also have bilateral gonads but lack a pharyngeal pad. The third, S. alanhongi, n. sp., has 35–47 segments, unilateral gonads, and a muscular pharyngeal pad. These species are distinguished from 18 known Saccocirrus spp. by their unique chaetation, number of segments, presence or absence of ventral cilia, and pygidial adhesive structures. Saccocirrus oahuensis consumes foraminiferans, and S. alanhongi contained diatoms, unicellular algae, and ostracods. These species add to the interstitial fauna of O‘ahu and cooccur with polychaetes Nerilla antennata (Nerillidae) and protodrilids (Protodrilidae), and Kinorhyncha. Saccocirrus alanhongi withstands almost daily disturbance by 600–1200 bathers per day entering the sandy swimming holes in the reef at Hanauma Bay.
Pacific Science Assocation
Index to Volume 57, pp. 485-490