Unsustainable urbanization in the Indo-Pacific continues to threaten terrestrial and aquatic ecosystems due to habitat disturbances driven by human pressures. The Marikina Watershed, one of the most critical watersheds in the Philippines, has been exposed to economic and population growth resulting in landscape modification and water quality degradation. This led to establishment of the Upper Marikina River Basin Protected Landscape (UMRBPL) to rehabilitate the watershed ecosystem. To strengthen this conservation initiative, we aimed to assess whether the establishment of UMRBPL has been effective in conservation of benthic macroinvertebrate diversity in streams of the Marikina Watershed. Sixteen streams, eight from UMRBPL and eight from adjoining unprotected areas, were monitored for benthic macroinvertebrate assemblages and their habitat environments, such as pH, water temperature, dissolved oxygen, total dissolved solids, conductivity, salinity, and canopy openness. Principal component analysis and non-metric multidimensional scaling based on the environmental variables and biological metrics, respectively, revealed that habitat quality and benthic macroinvertebrate assemblages significantly differed between the protected and unprotected streams, with the former having better environment and higher biodiversity. More precisely, protected streams have significantly higher dissolved oxygen and lower canopy openness and material loadings as compared to unprotected streams. Consequently, taxon richness was four-fold higher in protected streams while stream quality indices based on abundance of key invertebrate groups (EPT and EPTC) were ten-fold higher in protected streams, as compared to unprotected streams. This study demonstrates that freshwater protected areas play crucial roles in the conservation of stream ecosystems and biodiversity under rapid urbanization in developing countries, like the Philippines.

Six alien frogs have been introduced in the Philippines: chronologically, Hylarana erythraea, Rhinella marina, Lithobates catesbeianus, Hoplobatrachus rugulosus, Kaloula pulchra, and Eleutherodactylus planirostris. Here, we collected and synthesized historical and geographical data to reconstruct their history of invasion and to update their current invasion status and distribution in the Philippines. Four pathway categories (falling in 8 subcategories) have facilitated their introduction: (1) intentional ‘release’ for biological control and hunting in the wild; (2) ‘escape’ from farms; (3) ‘contamination’ of agricultural commodities, fish stocks, and ornamental plants/nursery materials; and (4) ‘stowaway’ on container/bulk and (hitchhiker on) ship/boat – of which the last two were important in most recent introductions. Their spatio-temporal pattern of distribution showed a stratified-diffusion process of spread involving primarily leading-edge and long-distance dispersal. The pathways that facilitated their secondary (post-introduction) long-distance dispersal were either the same as those of their introduction or shifted over time. Estimation of rate of spread showed that H. erythraea, R. marina, H. rugulosus, and K. pulchra have not reached spatial saturation and are conditioning to spread, with the latter spreading fastest. The status of Lithobates catesbeianus, whether it successfully established or not, is undetermined. Meanwhile, the other alien frogs are now considered fully invasive species, of which R. marina is the most widespread, whereas E. planirostris is the least distributed. Our study provides science-based information that can help guide the development and implementation of pathway-specific measures to prevent and control future and current invasions by alien frogs.

Pollinator populations are in decline worldwide. These declines are likely to impact native Hawaiian species and their interactions. To explore spatial heterogeneity in interactions between a foundational native Hawaiian tree and flower visitors, we examined how flower visitation varied for Metrosideros polymorpha over an elevational gradient, on the Island of Hawai‘i. We conducted a short-term, observational study at sites of high human activity, spanning a 1,500-m elevational gradient. We predicted that native flower visitors would be most important, where importance is defined as the product of the number of flower visitors observed and the number of flowers visited per visitor, at the highest elevations where human impacts have historically been less consistent and human populations are lower. We predicted that non-native bee visitation would be most important at the lowest elevations where human impact is highest. Contrary to our expectations, we found that the non-native honeybee, Apis mellifera, was the most important visitor at both the lowest and highest-elevation sites and second only to native species of Hylaeus bees in visitor importance at mid-elevation sites. We recorded A. mellifera interacting with flowers during 16.3% of all observation blocks and Hylaeus spp. during 9.4% of observation blocks, with all other visitors appearing more rarely. Although this study was short in duration and occurred at only six study sites in disturbed areas, our results suggest that the high importance of A. mellifera as a flower visitor of M. polymorpha is consistent across a range of environmental conditions. Hawai‘i's shifting suite of pollinators may impact gene flow and reproduction for M. polymorpha, a species with immense ecological and cultural importance.

Introduced pathogens causing emerging infectious diseases (EIDs) are serious contemporary threats to animal, plant, and ecosystem health. The invasive fungus, Pseudogymnoascus destructans, has established populations of European origin in North America, resulting in mass mortality of several hibernating bat species. Extensive monitoring for this pathogen exists in Europe and North America, but limited screening is taking place elsewhere. We report results from cave surveys on Hawai‘i Island. Substrates in 10 lava-tube caves with elevations up to 3,045 m were swabbed providing samples for screening P. destructans. Interior cave air temperatures spanned temperatures suitable for the growth and survival of P. destructans. Using quantitative PCR, all 85 samples tested were negative for the presence of P. destructans. The biology of the Hawaiian hoary bat (Lasiurus cinereus semotus) in relation to its unusual use of high elevation caves is discussed because these bats could come into contact with P. destructans should it arrive in Hawai‘i. Large numbers of cave enthusiasts visit Hawaiian caves from across the world after having been inside caves elsewhere including areas with P. destructans. Thus, resource managers in Hawai‘i and other remote areas may want to consider the potential for P. destructans to arrive unintentionally via human activities. Biosecurity measures and periodic screening for P. destructans are especially important in Hawai‘i given the presence of high elevation caves with suitable temperatures for its growth. If P. destructans was introduced to Hawaiian caves, it could affect the local fauna but also act as a source population for colonisations elsewhere.

Aphis gossypii Glover is cosmopolitan pest aphid, known to be represented by host-associated lineages. Although it is widespread in the Pacific Basin, there has been no assessment of this species in this region. We examined patterns of morphological variation within and among populations collected across hosts and islands using multivariate morphometric analyses. Genetic variation was determined using microsatellite flanking region sequences and mitochondrial cytochrome oxidase subunit 1. This study confirmed the existence of genetically distinct host-associated lineages. We found that host plant affects morphological expression and therefore morphological criteria cannot be used to identify lineages. Comments are provided on the origin and maintenance of these host lineages and implications for management of this important pest aphid species.

Age, growth and mortality of the goldlined seabream, Rhabdosargus sarba, were estimated based on 593 and 6516 specimens that were collected in waters off southwestern Taiwan from September 2015 to August 2016, and April 2015 to December 2017, respectively. The body weight (BW) and total length (TL) relationship (all data-pooled) was expressed as: BW = 0.01511 TL^3.0346 (r² = 0.95; n = 593). Growth rings (identified as opaque and translucent zones) were counted on 447 sectioned sagittal otoliths using a microscope under transmitted light and were counted up to 8 (42.0 cm TL) for both sexes. Edge analysis indicated that growth rings in otoliths were deposited once per year, and the opaque zone was formed in December. The von Bertanlanffy growth function (VBGF) best fit the observed length at age data for R. sarba. The growth parameters (±standard error) of VBGF for R. sarba (all data-pooled) were estimated as: L_∞ = 53.94 ± 3.71 cm TL, k = 0.217 ± 0.033 yr^-1, t₀ = –0.182 ± 0.167 yr (n = 447). Total mortality estimated from a length converted catch curve was 0.655 yr^-1, age-specific natural mortality and fishing mortality were estimated as 0.789–0.293 yr^-1 and 0.109–0.365 yr^-1, respectively. The exploitation rate was estimated to be 0.440.

Plant–parasitic green algae in the genus Cephaleuros infect leaves, twigs and fruits of numerous host plants worldwide. The reproductive structures of Cephaleuros are important in the infection process. The goal of this study was to determine the in vitro morphology and behavior of the zoospores and gametes of five Cephaleuros species: Cephaleuros karstenii, C. pilosa, C. solutus, C. virescens and Cephaleuros sp. Microscopic observations revealed that zoospores were ellipsoidal, rod-shaped, or spherical with four flagella. Gametes were spherical in shape with two flagella. Zoospores were released from all five Cephaleuros species, but gametes were released only by C. karstenii, C. solutus and Cephaleuros sp. After their release from gametangia, gametes swarmed in a water drop in irregular and circular motions until the resting stage; some gametes attached to each other, and others burst. Zoospores were released from papilla-pores located at the base of zoosporangia and swarmed in a water drop in irregular and circular motions. Some zoospores germinated and others burst, similar to the gametes. In this study, germinated zoospores formed germ tubes, and filaments containing carotenoid pigment, and then died without forming thalli.

Chromosome data are reported for 42 formally recognized angiosperm taxa and one natural hybrid, comprising 21 genera and 17 families occurring in the Hawaiian Islands, Fiji (Viti Levu) and Western Samoa (Upolu, Savaii). Included are first chromosome counts for 20 species. The relevance of the chromosome numbers to systematics and speciation of the investigated native taxa and the significance of counts obtained for non-native taxa are discussed.