The short-wavelength sensitive (S-) opsin gene OPN1SW is pseudogenized in some nocturnal primates and retained in others, enabling dichromatic colour vision. Debate on the functional significance of ...this variation has focused on dark conditions, yet many nocturnal species initiate activity under dim (mesopic) light levels that can support colour vision. Tarsiers are nocturnal, twilight-active primates and exemplary visual predators; they also express different colour vision phenotypes, raising the possibility of discrete adaptations to mesopic conditions. To explore this premise, we conducted a field study in two stages. First, to estimate the level of functional constraint on colour vision, we sequenced OPN1SW in 12 wild-caught Philippine tarsiers (Tarsius syrichta). Second, to explore whether the dichromatic visual systems of Philippine and Bornean (Tarsius bancanus) tarsiers—which express alternate versions of the medium/long-wavelength sensitive (M/L-) opsin gene OPN1MW/OPN1LW—confer differential advantages specific to their respective habitats, we used twilight and moonlight conditions to model the visual contrasts of invertebrate prey. We detected a signature of purifying selection for OPN1SW, indicating that colour vision confers an adaptive advantage to tarsiers. However, this advantage extends to a relatively small proportion of prey-background contrasts, and mostly brown arthropod prey amid leaf litter. We also found that the colour vision of T. bancanus is advantageous for discriminating prey under twilight that is enriched in shorter (bluer) wavelengths, a plausible idiosyncrasy of understorey habitats in Borneo. This article is part of the themed issue 'Vision in dim light'.
•Floral diameter remains a key differentiating trait in Philippine Rafflesia taxonomy.•An inverse relationship exists between floral diameter and latitudinal distribution.•All Philippine Rafflesia ...species, except R. speciosa, occur in only one island.
The Philippines is one of the centers of diversity of the genus Rafflesia (Rafflesiaceae). At present, 13 Rafflesia species have been recorded in the country. Prior to 2013, only 10 species of Rafflesia were found in the Philippines. Afterwards, two species have been described while one species has been resurrected. Morphological characteristics of the 13 species of Rafflesia in the Philippines were synthesized, from which an updated identification key is provided. Based on an analysis of the emerging patterns in morphology and distribution of Philippine Rafflesia, floral diameter remained a key differentiating trait in Rafflesia taxonomy. There is a significant inverse relationship between floral diameter and latitudinal distribution. The distribution map of all Philippine Rafflesia species, with their floral diameters drawn to scale, is presented wherein all species, except R. speciosa, occurred in only one island. Of the more than 7100 islands that make up the Philippine Archipelago, Rafflesia had been found in only five islands, which corresponded to three Pleistocene islands: the Greater Luzon, Greater Mindanao and the Greater Negros Panay.
Background:The Philippines serve as a habitat for at least 206 native species of terrestrial mammals, more than half of which are endemic to the country. From these, 78 bat species (order Chiroptera) ...have been described, with 26 identified as endemic. Scientific data on chiropterans is far from complete, and threats endanger many chiropteran populations. These problems necessitate the development of proper conservation and management measures, which can only be formulated to fit specific needs of certain species with enough knowledge about the taxon of concern. DNA barcodes facilitate the process of identification by providing an accurate, rapid, and more effective method of species recognition. Results: A 598-bp portion of the cytochrome c oxidase subunit 1 gene was sequenced from 130 individuals belonging to 33 species from chiropteran familes Pteropodidae, Rhinolophidae, Molossidae, Megadermatidae, Hipposideridae, Emballonuridae, and Vespertilionidae to create barcode records for these taxa. Neighbour-joining (NJ) trees of the COI sequences from this study and from GenBank and the Barcode of Life Data System (BOLD) was able to discriminate most species within each family. Several rhinolophid species, Rhinolophus arcuatus, R. inops, and R. subrufus, had low interspecific distances (<2%), and COI was not able to differentiate between them. Inspection of the NJ tree revealed distinct Philippine lineages of species recorded also from other countries as well as possible cryptic species within the different islands. Significance: This study generated new DNA barcodes for a more robust barcode data base that will aid environment officers in bio-monitoring and wildlife forensics. Results from the tree provides information about unique species lineages that can be further investigated by further studies using more comprehensive techniques, such as next-generation sequencing.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The establishment of Protected Areas is deemed of critical importance in global conservation initiatives, particularly in biodiverse regions and global biodiversity hotspots, such as the Philippines. ...However, the crucial role played by smaller Protected Areas in biodiversity conservation is frequently overlooked, making this a particular area of research interest. The Initao-Libertad Protected Landscape and Seascape (hereinafter – ILPLS) is one of the last remaining karst forests with natural vegetation and refuge for wildlife conservation on the island of Mindanao, the Philippines. However, the landscape component of this Protected Area is very small (ca. 506 000 m2), bisected by a road, and heavily disturbed by illegal logging and frequent tourist visits. From 2014 to 2018, we assessed the community structure and revealed patterns of bird diversity in ILPLS. We recorded a total of 814 individuals of birds from 36 species and nine feeding guilds from a total sampling effort of 558 230.40 mist-net hours in the Protected Areas' two management zones, namely the Special Protection Zone (SPZ) and Tourism Zone (TZ). ILPLS has a high level of endemism at 33% (12 species), including nine Philippine endemics and three Mindanao Island endemics. We also recorded Gorsachius goisagi, a globally threatened species categorised by IUCN as Vulnerable. Species richness was higher in the SPZ than in the TZ (p = 0.012), whereas no significant differences were observed in the Shannon index values (p = 0.101) and mean capture rates (p = 0.378) between the two management zones. Species and feeding guild assemblages did not differ between the two management zones (p = 0.939) but varied between vertical strata (p = 0.001). Here, we show how this small, protected landscape harbours a comparatively diverse bird community, including restricted-range species and species with high conservation priority. This suggests that forest fragments, even of this size, are important habitats for bird conservation efforts and should not be undervalued. We recommend extending such studies to other fragments, especially those that are still not protected, to improve our biodiversity database, further our understanding of biodiversity and fragment dynamics, and make a case for the protection of other forest fragment habitats.
Background: This study analyzed species boundaries within the genus Sardinella, focusing on the relationship between S. tawilis and S. hualiensis, the latter only recently reported from Philippine ...waters. Since fishes of the genus Sardinella are all marine, except for the S. tawilis, previous studies were designed to determine the closest marine relative of this Philippine-endemic species. Sardinella hualiensis was found to be morphologically similar to S. tawilis, so further molecular analysis was required to determine their relationship. Results: Mitochondrial cytochrome c oxidase I (COI) gene was used in this study. A neighbour-joining tree was constructed using sequence divergence values determined by the Kimura 2-parameter model. A single clade with 100% bootstrap support was formed, and the interspecific divergence ranged from 0% to 0.5220%, which is clearly below the suggested 3%-3.5% cutoff for species discrimination. An interesting outcome is the 0% genetic distance between S. tawilis and a Taiwanese specimen of S. hualiensis. Incipient allopatric speciation is a possible explanation for the low genetic distance between S. hualiensis and S. tawilis. A nuclear gene region, recombination activating gene 1 (RAG1), was used to further validate the findings of the study. Low interspecific genetic distances (0% to 1.1714%) provide additional evidence that S. tawilis and S. hualiensis belong to a single species. Significance: A more thorough understanding of the genetic status of S. tawilis could help with sustainability and management studies for this fish species, as it is the main source of income and livelihood for most of the locals in the Taal Lake area, where S. tawilis is endemic.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Water level fluctuations due to reservoir operations often cause spatial and temporal differences in water chemistry, which in turn can have considerable biological effects. Nonetheless, few studies ...have investigated the effects of fluctuating water levels on water quality and benthic macroinvertebrates in reservoirs in tropical countries, and none in the Philippine archipelago. We investigated the littoral zone of a Philippine reservoir subject to strong water level fluctuations and determined whether (i) water quality and macroinvertebrate community health is reduced when water levels are low, (ii) water quality declines with increasing water depth regardless of the overall water level, and (iii) water quality and community health decrease more strongly with water depth during low water level periods. Our study included five sites and four depths at each site, with three collections each during high and low water levels. Low water levels may have negatively affected four water quality and 10 biological metrics, whereas depth may have negatively affected two water quality and five biological metrics. Significant overall water levels by depth interactions were detected for four common taxa but none for water physicochemistry. Our findings show that tropical reservoirs may experience reduced water quality at low water levels, which can affect their biodiversity and potentially their ecological functioning.
Flower and fruit development of Rafflesia consueloae were studied between February 2014 and April 2016 in Pantabangan, Nueva Ecija, Philippines. Flower development was divided into five distinct ...phases: (1) emergence, (2) post-emergence, (3) bract, (4) perigone, and (5) anthesis. Fruit development was monitored from flower senescence until fruiting and maturation. A total of 512 individual buds were monitored – discovered at different stages of bud development. Only nine buds were monitored from post-emergence until the perigone phase. A bloom rate of 19.73% and an overall mortality rate of 77.34% were recorded. Mortality was highest during the early phases (post-emergence and bract) and lowest at the perigone phase. R. consueloae exhibited nocturnal flowering; wherein anthesis usually begins at dusk, signaled by the detachment of the first lobe, and from there on, full bloom took 15 ± 5.85 h to complete. Flowering was at its highest during the coldest and driest months of the year – between December and April. The growth rate is exponential, with an overall diameter growth of 1.80% every 4 d. The highest growth rate was recorded during the perigone phase. Six fruits, considered as dehiscent berries, ripened mostly in July – within 145 ± 11.03 d from anthesis.
An analytical biogeographlc analysis of urban bird diversity and abundance was conducted in the University of the Philippines Diliman campus from February to April 2005. Using the Jokimaeki urban ...bird census technique on four different land use subplots we observed 36 species of birds and 4036 cumulative counts individuals of these species. The open field area had the highest number of species (23) while the residential area had the lowest species number (14). The residential area has the highest bird counts and the College of Science complex had the lowest number of counts. Linear regression analysis of landscape features on bird abundances reveals that the number of trees and buildings are most significant predictors of abundances. Spatial features and the trophic characteristics of the bird species are not significant factors to account for abundance. Trees and buildings affect the distribution and abundance of urban exploiting species Passer montanus and Pycnonotus goiavler with the former favoring built spaces and the latter favoring trees. Analysis of species area curves suggests that the bird community of the campus is not homogenized and that certain habitats allow uncommon species to persist. We recommend that In order to increase bird biodiversity existing green spaces must be preserved, fruit trees planted and in areas reserved for building development, pocket gardens and rooftop gardens be included in the landscape architectural design.
PDF
