Pacific Science 53 (1999)

Pacific Science 53, no. 1

Conservation Status of Tree Snail Species in the Genus Partulina (Achatinellinae) on the Island of Hawai’i: A Modern and Historical Perspective
Lisa J. Hadway and Michael G. Hadfield, pp. 1-14

The Hawaiian tree snail genus Partulina, from Maui, Moloka’i, Lana’i, O’ahu, and the island of Hawai’i, is the sister genus of the endangered Achatinella, found only on the island of O’ahu. Life histories of species in the two genera are similar, and undoubtedly the Partulina species have been as severely impacted by the collective effects of habitat destruction and introduced predators as have those of the genus Achatinella. Three species of Partulina have been described from the island of Hawai’i: Partulina physa, P. confusa, and P. horneri. Until 1992, there were no recorded sightings of these species for more than 46 yr. Historically, Partulina spp. were recorded at various locations in almost all districts of the island of Hawai’i, including North and South Kona, North and South Kohala, Hamakua, North and South Hilo, and Puna. Historically, Partulina physa was found nearly island wide, whereas P. confusa and P. horneri were mostly located in the Hamakua and Kohala districts. Partulina confusa and P. horneri were not found in the current surveys. Extensive field surveys on the island of Hawai’i between May 1995 and December 1997 resulted in the location of only one population of Partulina physa, inhabiting a narrow range in the Kohala Mountains. The shell length and reproductive state were recorded for eighty-two individuals of P. physa from that population. Mean adult shell length was 15.08 mm. Habitat loss, much of which occurred between 200 and 100 yr ago, has likely been the greatest factor contributing to the decline of the Partulina spp. of the island of Hawai’i. Predation and shell collecting, and possibly climatic changes and pathogens, have also contributed to the decline of the Partulina species on Hawai’i Island. A small captive population of P. physa at the University of Hawai’i at Manoa has suffered high juvenile mortality (78%).

Aspects of the Reproductive Activity of Cypraea caputdraconis from Easter Island (Mollusca: Gastrpoda: Cypraeidae)
Cecilia Osorio, Donald Brown, Ligia Donoso, and Hugo Atan, pp. 15-23

Cypraea caputdraconis Melvill, 1888 (commonly known as pure), endemic to Easter Island, is an important mollusk in Easter Island handicrafts. Knowledge about its reproduction is necessary for sustainable management of this resource. Data presented here are from 14 monthly samples taken between 1989 and 1991. As in other species of the genus, C. caputdraconis populations sampled at Easter Island had a higher proportion of females (60.28%) than males. Females averaged slightly larger than males, but there was a large degree of size overlap between the sexes and lengths were not significantly different. Reproductive activity occurs year-round, as evidenced by the presence of all three gonadal stages at every sampling date, suggesting a reproductive cycle with continuous gametogenic activity, either lacking or with a very brief period of gonadal rest. Egg mass surveys indicate agreement between egg mass presence and gonadal maturity. Egg masses were recorded throughout the year. A decrease in the percentage of animals with egg capsules corresponded to a decrease in water temperature toward winter. Observations on behavioral sex expression in relation to brooding clearly point to the female as incubator, although in one instance a male was observed on the egg mass. The reproductive activity of the Easter Island pure may be tentatively characterized by a continuous reproductive cycle, with increased activity during spring and summer. We recommend closing this fishery during the period of peak reproductive activity to prevent overexploitation.

Redescription of Mesochaetopterus selangolus (Polychaeta: Chaetopteridae), Based on Type Specimens and Recently Collected Materials from Morib Beach, Malaysia
Eijiroh Nishi, pp. 24-36

Rullier constructed the monotypic genus Sasekumaria within the family Chaetopteridae in 1976. I studied the type specimens and recently collected material and transferred Sasekumaria selangola to the genus Mesochaetopterus established by Potts in 1914. Mesochaetopterus selangolus is characterized by two middle segments with extended notopodia, associated feeding organ, a J-shaped tube, and the porous end of the tube. The species closely resembles M. japonicus Fujiwara, 1934. Mesochaetopterus selangolus can be differentiated from M. japonicus by the number of notochaetae in the middle and posterior region, the number of teeth on the uncinal plates of the middle and posterior region, the morphology of the anal region, and the structure of the tube. Mesochaetopterus selangolus is compared with other species of the genus and diagnostic keys are provided.

Local Ecological Knowledge and Biology of the Land Crab Cardisoma hirtipes (Decapoda: Gecarcinidae) at West Nggela, Solomon Islands
Simon Foale, pp. 37-49

A rich body of local knowledge on the behavior and reproductive biology of the land crab Cardisoma hirtipes (called Kakau Tina in the Nggela language) is reported here from West Nggela, Solomon Islands. Aspects of West Nggela local knowledge about C. hirtipes were verified by observation, reports, and studies of the reproductive condition of crabs during the 1995–1996 wet season at West Nggela. Local ecological knowledge appeared to inform harvesting strategies and was congruent with scientific knowledge about the crabs. A behavior known as “dipping,” displayed by C. hirtipes before mating and ovulation, is well known to the Nggela people, but has not been reported in the biological literature for this species. Nggela people harvest C. hirtipes in large numbers when the crabs are dipping and can accurately predict the diel, lunar, and seasonal timing of this event. Cardisoma carnifex (Tubala in Nggela), which occurs in smaller numbers at West Nggela, plays a relatively minor role in the subsistence economy, and comparatively little local knowledge on its behavior and breeding biology was found.

Spatiotemporal Size-Class Distribution of Turbanella mustela (Gastrotricha: Macrodasyida) on a Northern California Beach and Its Effect on Tidal Suspension
Rich Hochberg, pp. 50-60

The size-class distribution of the marine interstitial gastrotrich Turbanella mustela was analyzed at a high-energy beach in northern California. Five 100-µm size classes, each corresponding to a particular sexual phase of the species, fluctuated in percentage abundance at both temporal and spatial scales. On average, the most abundant size classes over the 3-day period were the 100–199-µm group (prereproductive juveniles) and the 200–299-µm group (male phase). Significant differences were evident spatially, where aggregations at the vertical and horizontal level contributed to patchy size-class distributions. Members of the largest size class (postreproductive or male phase) were in low abundance, and juveniles and reproductive individuals made up the bulk of the population. The smallest size class (100–199 µm) was most aggregated in the top 5 cm of sand and differed significantly in percentage abundance from all other size classes at that depth. This size class is also the only size class to decrease significantly in percentage abundance on a vertical scale and increase in percentage abundance on a horizontal scale. Three hypotheses accounting for the observed size-class variations are entertained: sexual phase stratification, interspecific interactions, and intraspecific trophic relations. All three hypotheses are important for understanding the importance of these size-class aggregations and may lead to a better understanding of the factors that influence local spatial patterns in gastrotrichs. Size-class stratification may also function in the planktonic dispersal of individuals in both tidal and longshore directions, ultimately affecting the geographic distribution of the species.

Standing Crop and Sediment Production of Reef-Dwelling Foraminifera on O‘ahu, Hawai‘i
Jodi N. Harney, Pamela Hallock, Charles H. Fletcher III, and Bruce M. Richmond, pp. 61-73

Most of O’ahu’s nearshore and beach sands are highly calcareous and of biogenic origin. The pale-colored constituent grains are the eroded remains of carbonate shells and skeletons produced by marine organisms living atop the island’s fringing reefs and in the shallow waters near shore. Previous studies have shown that the tests of symbiont-bearing benthic foraminifera compose a substantial portion (up to one-fourth) of these organically produced sands. We sampled a variety of reef flat and slope habitats to obtain standing-crop data and production estimates for several sand-producing genera of reef-dwelling Foraminifera. We found that modern communities of these shelled protists occur in dense numbers islandwide, reaching densities up to 105 individuals per square meter of suitable substrate in the more productive habitats. Further research on the contribution of Foraminifera to beach, nearshore, and offshore sands is planned for O’ahu and neighboring islands to describe their roles in the sediment budget more completely.

Latitudinal Differences in Thermal Tolerance among Microscopic Sporophytes of the Kelp Lessonia nigrescens (Phaeophyta: Laminariales)
Enrique A. Martínez, pp. 74-81

The strong temperature increase during the 1982/1983 El Niño event caused local extinction of many species in large coastal zones of northern Chile and Peru. One brown algal species affected by massive mortality was the intertidal kelp Lessonia nigrescens Bory, with a latitudinal distribution from Cape Horn (55° S) to Peru (12° S). Between extreme localities of this distribution, mean annual seawater temperatures may differ by around 10°C. After the massive mortality of 1982/1983, some populations survived in a few localities of northern Chile, such as Iquique (20° S). I tested the hypothesis that these populations represent thermal ecotypes. Those from the north, close to the El Niño–impacted zone, should tolerate higher temperatures than southern populations. Microscopic sporophytes, cultivated from spores of plants collected in localities at the north, center, and south of Chile, were submitted to three temperature regimes. Two of them included the same average temperature, but different extreme values. Comparisons of thermal tolerance in the microscopic progeny from plants of the three Chilean localities showed that, at higher incubation temperatures, central and northern thermal ecotypes do have higher survival and growth rates than the ecotypes from the south. At lower incubation temperatures, the growth trend was reversed. Also, as suggested in the literature, sporophytic juveniles seem less tolerant than gametophytic microthalli. However, the differences in tolerance between northern and southern thermal ecotypes do not fully explain the survival of high seawater temperatures such as those of the 1982/1983 El Niño event by the northern populations.

Ultraviolet Floral Patterns in the Native Hawaiian Flora: What Do They Mean for Island Biogeography?
C. Eugene Jones, Deborah K. Dorsett, Faith M. Roelofs, and Chirag V. Shah, pp. 82-87

We examined 104 species (13%) of the approximately 784 species of biotically pollinated plants native to Hawai’i and found 14 (13.5%) that have an ultraviolet (UV) floral pattern. However, detailed examination revealed that 32% of the Hawaiian strand species have UV floral patterns, whereas only 8% of the upland species did. All of the flowers with UV patterns measured 1 cm or more in diameter and all but two appear yellow to humans. We discuss several possible explanations for the apparent paucity of UV floral patterns in the native Hawaiian upland flora.

Lana’i Island’s Arid Lowland Vegetation in Late Prehistory
Melinda S. Allen and Gail M. Murakami, pp. 88-112

Native Hawaiian dryland forests, important from both ecological and cultural perspectives, are among the more poorly known Hawaiian vegetation types. Wood-charcoal assemblages from archaeological features offer one means for investigating not only the composition of these diverse forests, but also the timing and mechanisms of their demise. Representing short-duration events, and relatively localized catchments, wood-charcoal assemblages provide different information from time-averaged, regional-scale pollen records. Analysis of the wood-charcoal evidence from the traditional Hawaiian settlement of Kaunolu, southwestern Lana’i, suggests that arborescent dryland forest species once extended into the island’s arid lowland regions. Moreover, many dryland forest taxa apparently persisted in this region until sometime after abandonment of the Kaunolu settlement in the mid-1800s. We suggest that although Native Hawaiians may have contributed to forest loss, ultimately some other mechanism, most likely exotic herbivores, transformed the southern coast of Lana’i into the arid grasslands seen today.

Abstracts of Papers from the Twenty-third Annual Albert L. Tester Memorial Symposium, 5–7 April 1998
pp. 113-122

Book Review: Vegetation of the Tropical Pacific Islands, by Dieter Mueller-Dombois and F. Raymond Fosberg
Michael F. Doyle, pp. 123-124

Pacific Science 53, no. 2

First Highly Stratified Prehistoric Vertebrate Sequence from the Galápagos Islands, Ecuador
David W. Steadman and Valerie E. Burke, pp. 129-143

We report an assemblage of ca. 6900 vertebrate fossils from a preliminary excavation at Barn Owl Cave, Isla Floreana, Galápagos 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 (Microlophis 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 Galápagos Islands.

A Reassessment of Dubautia (Asteraceae: Heliantheae-Madiinae) on Kaua‘i
Gerald D. Carr, pp. 144-158

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.

Occurence of Indigenous Plant Species in a Middle-Elevation Melaleuca Plantation on O‘ahu (Hawaiian Islands)
D. W. Woodcock, J. L. Perry, and T. W. Giambelluca, pp. 159-167

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.

Pocillopora inflata, A New Species of Scleractinian Coral (Cnidaria: Anthozoa) from the Tropical Eastern Pacific
Peter W. Glynn, pp. 168-180

Pocillopora inflata, n. sp., a relatively rare zooxanthellate scleractinian coral, is described from live colonies collected in the Galápagos 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 Galápagos 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 Galápagos 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.

Observations of a Probable Hybrid Angelfish of the Genus Holacanthus from the Sea of Cortez, México
Enric Sala, Octavio Aburto-Oropeza, and José L. Arreola-Robles, pp. 181-184

A probable new hybrid angelfish was observed in Cabo San Lucas, Baja California, México. 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.

Review of the Dragonets (Pisces: Callionymidae) of the Hawaiian Islands, with Descriptions of Two New Species
John E. Randall, pp. 185-207

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 Lana’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.

Description of a New Allopatric Sibling Species of Hawaiian Picture-Winged Drosophila
Kenneth Y. Kaneshiro and Michael P. Kambysellis, pp. 208-213

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.

Pacific Science 53, no. 3

A Case Study of Efficacy of Freshwater Immersion in Controlling Introduction of Alien Marine Fouling Communities: The USS Missouri
Richard Brock, Julie H. Bailey-Brock, and John Goody, pp. 223-231

The historically significant battleship USS Missouri was recently decommissioned and moved from Bremerton, Washington, to Hawai‘i to become a memorial museum at Pearl Harbor, O‘ahu, Hawai‘i. Dry-docking was completed in January 1993, and since that time the vessel has been part of the inactive fleet. In this 5-yr period, a dense growth of fouling organisms had developed on the outer surfaces of the hull. Out of concern that the fouled hull could become a source for the introduction of alien aquatic nuisance species to Hawaiian waters, an evaluation of the fouling community was conducted. In this study we found 116 taxa among 12 phyla in 10 samples scraped from the vessel’s hull. Seventy-six species were identified: 11 known from Hawaiian waters, 17 with known temperate-boreal distributions, and the remaining 48 known only from the Pacific Northwest. Forty percent of the taxa in this fouling community were not identified to species, so there remained some potential for alien species introduction. As a precaution to prevent accidental introductions, the ship was moved from Bremerton to the Columbia River in Oregon for a 9-day sojourn in freshwater before its transoceanic crossing to Pearl Harbor. Inspection of the vessel’s hull upon arrival in Pearl Harbor revealed more than 90% of the hull to be completely clear of any fouling organisms. Only 11 species were found to be alive: 3 species probably recruited to the hull on the transoceanic crossing that may routinely arrive in Hawaiian waters, 4 species already present in Hawai‘i, 3 Pacific Northwest species that appeared to be close to death on their arrival in Hawai‘i, and 2 euryhaline amphipod species probably recruited to the hull while in the Columbia River. The amphipods were not reproductive and brooding young, suggesting that these species would not be successful colonists. A final inspection and sampling of the hull 83 days after arriving at Pearl Harbor failed to find live or dead Columbia River amphipods nor were the three Pacific Northwest species alive. Freshwater exposure for 9 days coupled with increased water temperatures during the journey to Hawai‘i appear to be an extremely effective means of eliminating the temperate marine fouling community. This action substantially reduced the probability that an alien species would be introduced with the arrival of this historic vessel in Hawai‘i.

Rate of Spread of Introduced Rhodophytes Kappaphycus alvarezii, Kappaphycus striatum, and Gracilaria salicornia and Their Current Distributions in Kane‘ohe Bay, O‘ahu, Hawai‘i
S. Ku’ulei Rodgers and Evelyn F. Cox, pp. 232-241

Spread of the introduced macroalgae Kappaphycus alvarezii (Doty), Kappaphycus striatum Schmitz, and Gracilaria salicornia C. Ag. was measured on reefs in Kane‘ohe Bay, O‘ahu, Hawai‘i. The red algae Kappaphycus alvarezii and Gracilaria salicornia were introduced to specific sites in Kane‘ohe Bay in the 1970s. Since that time their distributions have increased, and the algae have spread through the bay. To assess the current extent of these algae in the bay and determine their rate of spread, we performed surveys with a manta towboard. In addition, abundance of these species was determined by detailed reef transects in the central bay in three habitats: barrier reef, patch reef, and fringing reef. All three species have become well established. These algae were found in all areas of Kane‘ohe Bay. Distributions are not uniform within the central bay. Abundance of Kappaphycus spp. was highest on patch reefs in shallow water. Gracilaria salicornia was most abundant on the fringing reef. Kappaphycus alvarezii and K. striatum have spread 6 km from their points of introduction in 1974, an average rate of spread of approximately 250 m/yr. Gracilaria salicornia has spread over 5 km since its introduction in 1978, an average rate of spread of approximately 280 m/yr. High abundance of these introduced species appears to be associated with moderate water motion.

Alien Rainbow Trout (Oncorhynchus mykiss) (Salmoniformes: Salmonidae) Diet in Hawaiian Streams
Michael H. Kido, Donald E. Heacock, and Adam Asquith, pp. 242-251

Diet of rainbow trout, Oncorhynchus mykiss (Walbaum), introduced by the State of Hawai‘i into tropical headwater streams of the Waimea River in the Koke‘e area of the Hawaiian island of Kaua‘i, is examined in this study through gut content analysis. In Wai‘alae Stream, rainbow trout were found to be opportunistic general predators efficient at feeding on invertebrate drift. Foods eaten ranged from juvenile trout, to terrestrial and aquatic arthropods, to algae and aquatic mosses. Native aquatic species, particularly dragonfly (Anax strennus) and damselfly (Megalagrion heterogamias) naiads, lymnaeid snails (Erinna aulacospira), and atyid shrimp (Atyoida bisulcata), were determined to be major foods for alien trout. Terrestrial invertebrates (primarily arthropods), however, provided a substantial (albeit unpredictable) additional food supply. Based on results of the study, it is cautioned that large numbers of rainbow trout indiscriminantly released into lower- to middle-elevation reaches of Hawaiian streams could do substantial damage to populations of native aquatic species through predation, competition, and/or habitat alteration.

Annual Dispersal Cycle of the Small Indian Mongoose (Herpestes auropunctatus) (Carnivora: Herpestidae) in Hawai‘i
Warren S. T. Hays, pp. 252-272

Four small Indian mongoose removal plots were monitored on two islands in Hawai’i during a 3-yr period. Both males and females showed natal dispersal in the fall. Males also dispersed during the breeding season. The capture rate of male dispersers decreased greatly between the beginning and the end of the breeding season, possibly indicating high seasonal mortality rates. Ramifications for population management are discussed.

Island Environment and Landscape Responses to 1997 Tropical Cyclones in Fiji
James P. Terry and Rishi Raj, pp. 257-272

Principal responses of the physical environment of the Fiji Islands to tropical cyclones Gavin and June in 1997 were investigated. These cyclones, which entered Fiji waters in March and May 1997, respectively, were the first severe tropical depressions to traverse Fiji since 1993. Northern and western islands were the most severely affected. Hurricane-force winds, intense rainfall, and temporary storm surge caused damaging effects, including widespread flooding, landslides, and coastal degradation. Different tropical cyclones produce contrasting patterns of landscape change on Pacific islands, depending on strength and duration of the storms, proximity of the storm tracks to land, rainfall totals and maximum intensities, hydrological behavior of the vegetation and soils, and many other factors influencing the environmental susceptibility of the islands concerned. Spatial patterns in the environmental responses of Fiji to cyclones Gavin and June were assessed using satellite images of the storms’ movements and data on rainfall, river rises, landslide occurrence, and coastal inundation. Field observations at some of the worst affected areas demonstrate the magnitude of these effects.

Botany and Genetics of New Caledonian Wild Taro, Colocasia esculenta
Anton Ivancic and Vincent Lebot, pp. 273-285

Taro, Colocasia esculenta (L.) Schott, is considered to be an introduced crop in New Caledonia and has been cultivated since its introduction by Melanesian farmers. Wild germplasm exists on the main (continental) island and is represented by three easily distinguished morphotypes: a morphotype with purple leaves, another with green leaves, and a third with green leaves and a purple vein junction on the lamina. All three morphotypes are diploids (2n = 2x = 28) and have well-established wild populations in many valleys and gulches of the main island. The morphotype with purple leaves has all typical traits of a wild genotype (inedible corms; long, thin stolons); the other two produce edible corms. The purple and the green morphotypes flower and produce fertile pollen. The spathes of the green morphotype can be more than 40 cm long and the spadix is characterized by an extremely long appendix atypical for Pacific taros. Isozyme analysis conducted using four enzyme systems (EST, PGM, PGI, SkDH) indicated that New Caledonian wild taros differ from most widely grown local cultivars and Pacific cultivated and wild genotypes. Evidence presented in this study suggests that C. esculenta is an endemic species to New Caledonia. Cultivars were probably introduced as clones from what is now Vanuatu by early Melanesian migrants and were not domesticated locally from existing wild forms, which appear to be genetically distant from other Melanesian wild taros.

Ecological Observations on Dialommus fuscus (Labrisomidae), the “Four-Eyed Blenny” of the Galápagos Islands
Jürgen Nieder, pp. 286-288

Information is presented on the behavior, abundance, and distribution of Dialommus fuscus Gilbert in its intertidal habitat on the island of Santa Cruz, Galápagos Archipelago, Ecuador.

Two New Pacific Ocean Species of Hyocrinid Crinoids (Echinodermata), with Comments on Presumed Giant-Dwarf Gradients Related to Seamounts and Abyssal Plains
Michel Roux and David L. Pawson, pp. 289-298

Hyocrinus foelli, n. sp. is a small hyocrinid sea lily from the abyssal ferromanganese nodule fields of the North Pacific Ocean. Hyocrinus giganteus, n. sp. is a very large hyocrinid from Horizon Seamount in the eastern Pacific that shows close affinities to H. cyanae from the western Pacific, off New Caledonia. A possible giant-dwarf heterochronic gradient, related to scarcity of food supply in abyssal plains and its abundance in seamount environments, is discussed.

Nerillidae of Hawai‘i: Two New Records of Interstitial Polychaetes
Julie H. Bailey-Brock, pp. 299-304

Two species of the polychaete family Nerillidae are reported from sand collected from the south shore of O‘ahu, Hawai‘i. Nerilla antennata O. Schmidt was collected from a shallow fringing reef, and Mesonerilla fagei Swedmark with coarse sand from Honolulu Harbor. Both are less than 0.5 mm in length and occupy an interstitial habitat. Nerilla antennata has a broad geographic distribution including Atlantic, Pacific, and Indian Oceans, and M. fagei is known from the North Atlantic. The morphology of Hawaiian specimens is described and reproductive stages of M. fagei are illustrated.

Abundance and Horizontal Distribution of Meiofauna on a Northern California Beach
Matthew D. Hooge, pp. 305-315

Distribution and abundance of meiofauna on a sandy beach in Big Lagoon, California, were studied during a 3-week period in the summer of 1996. Sediment cores were taken to a depth of 10 cm at three tidal levels. In addition to quantitative counts of meiofauna, exposure to air, percentage water content, and grain size composition were determined for each sample. Results of Spearman rank correlations revealed that median grain size, percentage exposure to air, and sediment saturation were strongly correlated to differences in meiofauna abundance at the mid and low water stations. Mean meiofauna abundance was 779 individuals per 100 cm3 of sand. Nematodes and oligochaetes made up approximately 80% of the mean abundance at the mid water stations. Although polychaetes accounted for approximately 70% of the mean total meiofauna at the low water stations, the most numerically dominant group varied on different sampling days and included polychaetes, gastrotrichs, turbellarians, and nematodes. New distributional records for Northern California include Nematoplana nigrocapitula (Turbellaria, Proseriata), Turbanella mustela (Gastrotricha, Macrodasyida), and Microcerberus abbotti (Isopoda, Microcerberoidea).

Pacific Science 53, no. 4

New Behavioral, Ecological, and Biogeographic Data on the Avifauna of Rennell, Solomon Islands
Christopher E. Filardi, Catherine E. Smith, Andrew W. Kratter, David W. Steadman, and H. Price Webb, pp. 319-340

During an expedition to Rennell, Solomon Islands, from 20 to 30 June 1997, we collected specimen and observational data that add to our understanding of this island’s unique avifauna. We observed three species previously unrecorded on Rennell: a putative caprimulgid species, the Tree Martin (Hirundo nigricans), and the Black-faced Cuckoo-shrike (Coracina novaehollandiae), suggesting that further research will add to the known Rennell avifauna. In combination with previous work, our specimen data suggest that many Rennellese land birds have prolonged breeding seasons typical of those of birds of lowland tropical regions. Our observations indicate that two species, the Great Cormorant (Phalacrocorax carbo) and the Singing Starling (Aplonis cantoroides), have colonized Rennell and increased in abundance over the past several decades. Reported initially as vagrants, the population establishment and increases of these two species portend the importance of vagrant species on islands subjected to increased human disturbance.

Rare Sighting of a North Pacific Right Whale (Eubalaena glacialis) in Hawai‘i
Dan R. Salden and Jill Mickelsen, pp. 341-345

On 2 April 1996, a North Pacific right whale (Eubalaena glacialis) was sighted in the company of three humpback whales (Megaptera novaeangliae) off the western coast of Maui, Hawai‘i (20° 56′ N, 156° 46′ W). The right whale appeared to initiate social interactions with the humpback whales. The right whale was estimated to be 13 m in length. Its sex was undetermined. This represents the first confirmed sighting of a right whale in Hawaiian waters since 1979. The 1996 sighting was similar to those in 1979 in that a solitary right whale was observed interacting with humpback whales during a 17-day period in late March and early April. In all but one instance, there were three or more humpbacks present.

The Freshwater Ichthyofauna of Bougainville Island, Papua New Guinea
J. H. Powell and R. E. Powell, pp. 346-356

Tailings disposal from the Bougainville Copper Limited open-cut porphyry copper mine on Bougainville Island, Papua New Guinea (1972-1989) impacted the ichthyofauna of the Jaba River, one of the largest rivers on the island. To assess the extent of this impact, comparative freshwater ichthyological surveys were conducted in five rivers on the island during the period 1975-1988. Fifty-eight fish species were recorded, including one introduction of Oreochromis mossambicus. The icthyofauna are dominated by euryhaline marine species consistent with that of the Australian region, but more depauperate. There are more than 100 species present on mainland New Guinea that are absent from Bougainville streams. Oreochromis mossambicus was the most abundant species in the sampled streams, accounting for 45% of the catch. The most abundant native fishes were the mainly small Gobiidae and Eleotridae. There were very few native fish of potential value as food and these were restricted to an eleotrid gudgeon (Ophieleotris aporos), tarpon (Megalops cyprinoides), eel (Anguilla marmorata), and snappers (Lutjanus argentimaculatus and Lutjanus fuscescens). Fish production in the rivers is limited by the morphology of the streams and the depauperate ichthyofauna. Fish yield from the Jaba River in its pre-mining state is estimated to range from 7 to 12 t/yr. The population living in the Jaba catchment in 1988 (approximately 4,600 persons) shared this resource, resulting in an extremely low per-capita fish consumption rate of less than 3 kg/yr.

Caranx caballus, a New Immigrant Carangid Fish to the Hawaiian Islands from the Tropical Eastern Pacific
John E. Randall and Bruce A. Carlson, pp. 357-360

Caranx caballus Günther, a wide-ranging tropical eastern Pacific carangid fish, was reported from Hawaiian Islands as C. kuhlii (later as C. kalla) from only two specimens collected in 1922. As no further specimens have been collected, these two fish were regarded as strays from the eastern Pacific; however, beginning in the summer of 1998, this small jack was found in such numbers in the Hawaiian Islands that it seems to have established a breeding population. It is distinguished by having 22-24 dorsal soft rays, 19-20 anal soft rays, 43-52 scutes, chest fully scaled, 42-46 gill rakers, no large teeth in jaws, a relatively slender body (depth 3.5-3.75 in fork length), a black spot on edge of opercle, and no dark bars on the body. Because it is a valuable food fish, it is expected to be commercially exploited in Hawai’i.

Some Preliminary Findings on the Nutritional Status of the Hawaiian Spiny Lobster (Panulirus marginatus)
Frank A. Parrish and Theresa L. Martinelli-Liedtke, pp. 361-366

Data on the nutritional status of spiny lobster (Panulirus marginatus) were collected on the commercial trapping grounds of Necker Bank, Northwestern Hawaiian Islands, in the summers of 1991, 1994, and 1995. Glycogen levels measured in abdominal tissue of intermolt males were used as an index of nutritional health of the field population. The range of glycogen sampled from wild lobster was less than half the level measured in captive lobster fed to satiation in a previous study. An analysis of covariance identified significant interannual and spatial effects explaining 46% of the variance in the sample of wild lobsters. Most significant was a decline in lobster glycogen levels between samples collected in 1991 and 1994-1995. Seasonal influences on lobster nutrition are unknown and were identified as an obvious direction for future ecological research.

Intrusion of Anchialine Species in the Marine Environment: The Appearance of an Endemic Hawaiian Shrimp, Halocaridina rubra, on the South Shore of O‘ahu (Hawaiian Islands)
Julie H. Bailey-Brock, Vernon R. Brock, and Richard E. Brock, pp. 367-369

A single specimen of the endemic anchialine shrimp Halocaridina rubra was collected on the reef under a brick in a fresh water extrusion in the lower intertidal at Kawaiku‘i Beach Park, Niu Valley, O‘ahu, Hawai‘i, on 25 December 1998. Repeated collecting efforts at low tides failed to produce more shrimp. The associated fauna includes an anadromous eleotrid fish, Eleotris sandwicensis (the ‘o’opu ‘akupa), isopods Apanthura inornata and Talitroides sp., alpheid shrimp (Alpheus crassimanus), an oligochaete, and gobioid fish (Bathygobius fuscus). Fresh water seeping out across the sand and visible in the area at low tides may have been the source of the specimen. This find may represent a rare occurrence of H. rubra in the reef flat habitat or the intrusion of anchialine species may occur with some frequency after heavy rains when the groundwater flow increases.

New and Previous Records of Scleractinian Corals from Clipperton Atoll, Eastern Pacific
Juan P. Carricart-Ganivet and Héctor Reyes-Bonilla, pp. 370-375

Clipperton Atoll was visited from 23 to 25 November 1997. A total of 109 specimens of stony corals belonging to two orders, seven families, and 15 species was collected. Five taxa of Scleractinia represent new records for the atoll: Porites lutea, Porites australiensis, Psammocora superficialis, Astrangia sp., and Balanophyllia sp. With these new records and species previously reported in the literature, the total number of scleractinians now known at Clipperton Atoll is 18 species. Observations on the fossil terraces on the island and on the dead coral fauna of the inner lagoon are presented.

Twenty Years of Disturbance and Change in Fagatele Bay National Marine Sanctuary, American Samoa
A. L. Green, C. E. Birkeland, and R. H. Randall, pp. 376-400

Fagatele Bay National Marine Sanctuary contains a moderately diverse coral reef community (150 coral species, 259 fish species) is protected from most human activities. The coral community was devastated by a crown-of-thorns starfish invasion in 1979 and has recently been affected by two major hurricanes (1990 and 1991) and a period of unusually high water temperature (1994). Long-term monitoring of the sanctuary allows for the description of the effects of these disturbances in the absence of anthropogenic processes. The crown-of-thorns damaged the deeper portions of the coral communities most severely, while the hurricanes and warm water affected shallower portions to a greater degree. Soon after these disturbances, corals started recruiting abundantly and the reefs began to recover. This is in contrast to some other areas in American Samoa, where chronic anthropogenic affects appear to have inhibited coral recruitment and reef recovery. Fish communities were affected by the habitat degradation associated with the crown-of-thorns outbreak, but have remained relatively unchanged ever since.

Hawaiian Plant DNA Library II: Endemic, Indigenous, and Introduced Species
Rebecca A. Randell and Clifford W. Morden, pp. 401-417

The Hawaiian Plant DNA Library of endemic and indigenous plant species preserves genetic material from all Hawaiian Islands. DNA accession numbers are reported here for 155 native species representing 92 genera and 48 families. The federal status of endangered species is indicated where applicable. Accessions for 71 species in 52 genera and 10 families of introduced species are also reported. Pest and invasive species are also indicated.

Measuring Stem Growth Rates for Determining Age and Cohort Analysis of a Tropical Evergreen Tree
Grant Gerrish and Dieter Mueller-Dombois, pp. 418-429

Metrosideros polymorpha (Myrtaceae) is the dominant canopy tree in many Hawaiian lowland and montane rain forests. It is a shade-intolerant species that persists throughout forest succession. Stands usually regenerate following synchronized dieback of the canopy cohort. Like most tropical evergreen trees, Metrosideros does not form growth rings, making determination of tree age and stand turnover rates difficult. This study measured the annual stem diameter growth rate for 3 yr in cohorts of six different stem size classes on young volcanic substrates at 1100 m above sea level on the island of Hawai’i. These side-by-side cohorts were assumed to represent a chronosequence of stand development in early primary succession. The growth rates were used to predict mean cohort tree age based on mean tree diameter, adjusting for variation in growth rate during the life cycle of the trees. The mean annual growth rate was about 2 mm/yr for all the cohorts except the largest, which was significantly lower. This cohort was undergoing stand dieback, with regeneration of a new cohort, and is assumed to represent the terminal stage of the cohort life cycle. The predicted age of this cohort was about 200 years; this appears to be a reasonable estimate of the turnover rate for cohorts in this environment. Individual growth rates within cohorts were highly variable. Other parameters, such as crown area and nearest neighbor distances, could not account for the variation. Analysis indicates that the growth rate of each individual tree probably fluctuates about the mean growth rate throughout its life. Year-to-year variation in mean cohort growth rates was significant only for the two largest cohorts. For these large trees, mean growth rate was negatively associated with rainfall. It is suggested that these trees may be light limited, because solar radiation itself is known to be negatively correlated with annual rainfall in the study area.

Pacific Science 53, Index


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