Biology and Impacts of Pacific Island Invasive Species. 5. Eleutherodactylus coqui, the Coqui Frog (Anura: Leptodactylidae)
Karen H. Beard, Emily A. Price, and William C. Pitt, 297-316
The nocturnal, terrestrial frog Eleutherodactylus coqui, known as the Coqui, is endemic to Puerto Rico and was accidentally introduced to Hawai‘i via nursery plants in the late 1980s. Over the past two decades E. coqui has spread to the four main Hawaiian Islands, and a major campaign was launched to eliminate and control it. One of the primary reasons this frog has received attention is its loud mating call (85–90 dB at 0.5 m). Many homeowners do not want the frogs on their property, and their presence has influenced housing prices. In addition, E. coqui has indirectly impacted the floriculture industry because customers are reticent to purchase products potentially infested with frogs. Eleutherodactylus coqui attains extremely high densities in Hawai‘i, up to 91,000 frogs ha⁻¹, and can reproduce year-round, once every 1–2 months, and become reproductive around 8–9 months. Although the Coqui has been hypothesized to potentially compete with native insectivores, the most obvious potential ecological impact of the invasion is predation on invertebrate populations and disruption of associated ecosystem processes. Multiple forms of control have been attempted in Hawai‘i with varying success. The most successful control available at this time is citric acid. Currently, the frog is established throughout the island of Hawai‘i but may soon be eliminated on the other Hawaiian Islands via control efforts. Eradication is deemed no longer possible on the island of Hawai‘i.
Estimation of the Origin of Polypedates leucomystax (Amphibia: Anura: Rhacophoridae) Introduced to the Ryukyu Archipelago, Japan
Norihiro Kuraishi, Masafumi Matsui, and Hidetoshi Ota, 317-325
We attempted to estimate the origin of the exotic frog Polypedates leucomystax in the Ryukyu Archipelago. This species was first found in 1964 just in front of the U.S. military base at Kadena on Okinawajima Island and currently has established feral populations on more than 20 islands. We conducted phylogenetic analyses using mitochondrial DNA sequences of the cytochrome b gene. Samples of P. leucomystax from five islands of the Ryukyus had a single haplotype, which was identical to that of a Philippine sample but quite different from haplotypes of Vietnamese samples. Samples of P. megacephalus from Taiwan formed a clade different from the P. leucomystax clade. From these results, P. leucomystax in the Ryukyus seems to have originated through accidental transportation of very few individuals with military cargo from somewhere around the Philippines.
Endoparasites of Eleven Species of Ranid Frogs (Anura: Ranidae) from Papua New Guinea
Stephen R. Goldberg, Charles R. Bursey, and Fred Kraus, 327-337
Two hundred eighty-eight ranid frogs from Papua New Guinea collected from 2002 to 2005 were examined for endoparasites: Platymantis adiastolus, P. boulengeri, P. browni, P. gilliardi, P. papuensis, P. schmidti, Rana daemeli, R. garritor, R. jimiensis, R. milneana, and R. papua. Found were one species of Cestoda (as cysticerci), three species of Digenea (Opisthioglyphe cophixali, Diplodiscus amphichrus, and Mesocoelium monas), 18 species of Nematoda (adults of Abbreviata oligopapillata, Aplectana krausi, Aplectana macintoshii, Aplectana zweifeli, Cosmocerca novaeguineae, C. tyleri, Desmognathinema papuensis, Falcaustra papuensis, Icosiella papuensis, Meteterakis crombiei, Ochoterenella papuensis, Paracapillaria spratti, Pseudorictularia dipsarilis, Rhabdias australiensis, Seuratascaris numidica, larvae of Abbreviata sp., and Ascaridae gen. sp.), two species of Acanthocephala (Acanthocephalus bufonis and cystacanths of a second species), and one species of Pentastomida (nymphs of Kiricephalus sp.). Sixty-seven new host records, one new country record, and several new island records are reported. Nematodes composed 18/24 (75%) of the species present. Thirteen of the 24 endoparasite species found currently appear to be endemic to Papua New Guinea.
Black Rat (Rattus rattus) Predation on Nonindigenous Snails in Hawai‘i: Complex Management Implications
Wallace M. Meyer III and Aaron B. Shiels, 339-347
Understanding interactions among nonindigenous species that pose a threat to native species is crucial to effectively preserve native biodiversity. Captive feeding trials demonstrated that the black rat, Rattus rattus, will readily consume two of the most destructive nonindigenous snails, the giant African snail, Achatina fulica (100% predation), and the predatory snail Euglandina rosea (80% predation). Rats consumed snails from the entire size range offered (11.5 to 59.0 mm shell length), suggesting that there is no size refuge above which snails can escape rat predation. Damaged E. rosea shells from the captive feeding trials were compared with shells collected in the Wai‘anae Mountains, O‘ahu. This revealed evidence that R. rattus is responsible for at least 7%–20% of E. rosea mortality. However, this is likely a substantial underestimate because 67% of E. rosea shells in the captive feeding trials were damaged in such a way that they would not have been collected in the field. Therefore, we hypothesize that reduction or eradication of R. rattus populations may cause an ecological release of some nonindigenous snail species where these groups coexist. As such, effective restoration for native snails and plants may not be realized after R. rattus removal in forest ecosystems as a consequence of the complex interactions that currently exist among rats, nonindigenous snails, and the remaining food web.
A Recent Outbreak of the Hawaiian Koa Moth, Scotorythra paludicola (Lepidoptera: Geometridae), and a Review of Outbreaks between 1892 and 2003
William P. Haines, Mandy L. Heddle, Patricia Welton, and Daniel Rubinoff, 349-369
The koa moth, Scotorythra paludicola, is an endemic Hawaiian moth that undergoes sporadic outbreaks in koa forests in Hawai‘i, causing vast defoliations of its host plant, Acacia koa. We studied one such outbreak that occurred on East Maui in 2003, in which approximately 16 km² of forest were defoliated. We collected adult moths and larvae, and recorded size-class distribution of larvae in defoliated regions. Larvae at a given site tended to be of a similar size class, suggesting that outbreaks were synchronous, and mean development time from first instar to adulthood was 42 days under laboratory conditions. Mortality of field-collected, laboratory-reared larvae due to disease was high (80%), making it impossible to quantify meaningful parasitism rates, but three nonnative hymenopteran primary parasitoids were reared (the braconids Meteorus laphygmae and Cotesia marginiventris, and the ichneumonid Hyposoter exiguae). One ichneumonid hyperparasitoid, Gelis sp., was also reared. No native parasitoids were reared. We found no relationship between occurrence of five koa moth outbreaks on East Maui between 1920 and 2006 and annual or monthly precipitation or temperature during that period.
Short-Range Movements of Hawksbill Turtles (Eretmochelys imbricata) from Nesting to Foraging Areas within the Hawaiian Islands
Denise M. Parker, George H. Balazs, Cheryl King, Larry Katahira, and William Gilmartin, 371-382
Hawksbill sea turtles, Eretmochelys imbricata, reside around the main Hawaiian Islands but are not common. Flipper-tag recoveries and satellite tracking of hawksbills worldwide have shown variable distances in post-nesting travel, with migrations between nesting beaches and foraging areas ranging from 35 to 2,425 km. Nine hawksbill turtles were tracked within the Hawaiian Islands using satellite telemetry. Turtles traveled distances ranging from 90 to 345 km and took between 5 to 18 days to complete the transit from nesting to foraging areas. Results of this study suggest that movements of Hawaiian hawksbills are relatively short-ranged, and surveys of their foraging areas should be conducted to assess status of the habitat to enhance conservation and management of these areas.
Growth and Distribution of the Macroalgae Gracilaria salicornia and G. parvispora (Rhodophyta) Established from Aquaculture Introductions at Moloka‘i, Hawai‘i
Stephen G. Nelson, Edward P. Glenn, David Moore, and Brendan Ambrose, 383-396
Gracilaria salicornia and G. parvispora were introduced to the south reef of Moloka‘i, Hawai‘i, in the past 15–20 yr for aquaculture development. Both species have naturalized on the reef. Gracilaria salicornia is now considered an invasive species on O‘ahu due to its tendency to grow in dense beds that produce undesirable windrows of thalli on the beach. There is also concern that it reduces biodiversity and degrades habitats of reefs. We surveyed the south coast of Moloka‘i, where both species were introduced, and measured biomass density, growth rates, and thallus nutrient contents of G. salicornia in established beds. Both species are found in the silt-laden, nearshore zone of the reef within 50 m of shore. Gracilaria salicornia grows in dense beds containing 475 g dry weight m⁻² of biomass, but growth rates are low, 0.03%–1.28% day⁻¹. Tissue nitrogen levels are low, suggesting that these populations are nitrogen limited. Nevertheless, populations of G. salicornia persist and grow slowly on the reef, whereas those of G. parvsipora are only found in areas of local nitrogen enrichment from anthropogenic sources. Currently, G. salicornia does not appear to be negatively affecting the reef ecology on Moloka‘i, because it is confined to the disturbed, nearshore zone. However, its ability to grow slowly and persist under low-nitrogen conditions allows it to form dense beds and suggests that it will eventually spread farther along the coast.
The Soils of Kiritimati (Christmas) Island, Kiribati, Central Pacific: New Information and Comparison with Previous Studies
R. J. Morrison and C. D. Woodroffe, 397-411
Kiritimati, the largest land area atoll in the world, is undergoing rapid population increase, and, given the isolation of the island, local food production will have to be expanded to support the residents. Two soils investigations were completed in the 1960s, but no additional information on the soil resources of the island has been produced since that time. In this study, 15 soil profiles were described and analyzed. Where possible, comparison has been made with previous work, and discussion of the soil-forming factors is presented. Results confirm that soils are weakly developed (Entisols) with relatively low organic matter contents and low water-retention capacity. These properties are expected from the age of the parent materials and the relatively dry climate of the island. Total elemental analyses show that the soils contain very low concentrations of potassium and important trace elements (iron, manganese, copper, and zinc), which will limit any plant production. Classification of the soils identified eight soil families, mainly separated on the basis of content of larger coarse fragments and soil moisture regime, including the influence of groundwater. Comparison with previous studies showed that although different nomenclature and classification systems were used, similar soil patterns were observed, and the soils of Kiritimati are relatively unique in the Pacific islands.
Review of Octocorallia (Cnidaria: Anthozoa) from Hawai‘i and Adjacent Seamounts. Part 2: Genera Paracalyptrophora Kinoshita, 1908; Candidella Bayer, 1954; and Calyptrophora Gray, 1866
Stephen D. Cairns, 413-448
Nine deep-water primnoid octocoral species are described from Hawaiian waters, four of them as new species, bringing the total number of octocoral species known from Hawai‘i to 94. Candidella gigantea is reported for the first time subsequent to its original description from Fiji in 1889. To place the two new species of Calyptrophora in context, all 16 species in the genus are keyed and analyzed in a morphology-based phylogenetic analysis. Although the analysis did not support the species complexes and species groups established by Bayer, it did suggest two distinct clades based on characters such as the opercular cowl, inclination of the polyps, and cross section and sculpture of the basal scale spines.
Currently Known and Reported Discomycetes (Ascomycota) of Hawai‘i
George J. Wong and Richard P. Korf, 449-456
A species list of Discomycetes that occur in Hawai‘i has been compiled that includes all previously reported species in the literature. Comments are provided for reports if there are changes in nomenclature, author citation, or for taxonomic revisions based on reexamination of collections. Fifteen taxa, new to Hawai‘i, are reported. The list of accepted taxa includes a total of 47 species, one including two subspecies. Three previously reported species were misidentified and apparently do not occur in Hawai‘i. Three species formerly reported as Discomycetes are now excluded as Dothideomycetes. The relatively small number of species of Discomycetes recorded from Hawai‘i is probably due to lack of an exhaustive effort to survey this group of Fungi. Although some species are recorded as growing on endemic or indigenous host plants, species of Discomycetes were not designated as endemic or indigenous due to insufficient knowledge of species distribution and the wide range of variations in host preferences.
Association Affairs, 457