26 research outputs found
Purtscher-like retinopathy following valsalva maneuver effect: case report
<p>Abstract</p> <p>Introduction</p> <p>Purtscher's retinopathy is a rare condition that is noted in cases related to various types of trauma. The characteristic finding in the fundus is the presence of multiple Purtscher flecken. Purtscher-like retinopathy has a similar presentation in the fundus, but without an association with trauma.</p> <p>Case presentation</p> <p>A 43-year old Malay man presented with a sudden onset of central foggy vision in the left eye after holding his breath for two minutes while catching a falling object. It was not associated with floaters, flashes of light, or head trauma. His vision in the right eye was 6/6, and in his left eye it was finger counting. He had bilateral temporal sub-conjunctival hemorrhages. An examination of his left fundus revealed multiple white cotton wool spots and dot-blot retinal hemorrhages with diffuse retinal edema at the posterior pole. His right fundus was noted to have only mild temporal peri-papillary edema associated with a few dot-blot hemorrhages. Fundus fluorescein angiography showed good arterial perfusion and no evidence of leaking or neo-vascularization. A diagnosis of Purtscher-like retinopathy was made, and the patient was treated with indomethacin tablets for six weeks. At his six-week follow-up examination, his left eye visual acuity had improved to 6/12. His bilateral sub-conjunctival hemorrhage had resolved. His left fundus showed residual multiple cotton wool spots and reduced retinal edema.</p> <p>Conclusions</p> <p>Treatment with non-steroidal anti-inflammatory drugs seems to be effective in reducing edema in patients with Purtscher-like retinopathy.</p
Hybridization between damselfishes Dascyllus aruanus and D. reticulatus on the Great Barrier Reef
[Extract] Hybridization among closely related species is relatively common in marine fishes thatspawn mid-water. Although at least 81 species of tropical coral-reef fish have been reported to hybridize in nature (primarily Chaetodontidae, Pomacanthidae and Labridae), hybridization is thought to be exceedingly rare among benthic-nesting species that engage in pair spawning, such as the Pomacentridae (Montanari et al.2016 ). The Pomacentridae include >385 species, most of which form breeding pairs and nest on the benthos. Yet only four Pomacentridae hybridshave been confirmed based on strong molecular evidence (e.g., Yaakub et al. 2006), and only from areas where one or both species are rare, such as degraded habitats and/or geographic zones of overlap
Naturally occurring hybrids of coral reef butterflyfishes have similar fitness compared to parental species.
Hybridisation can produce evolutionary novelty by increasing fitness and adaptive capacity. Heterosis, or hybrid vigour, has been documented in many plant and animal taxa, and is a notable consequence of hybridisation that has been exploited for decades in agriculture and aquaculture. On the contrary, loss of fitness in naturally occurring hybrid taxa has been observed in many cases. This can have negative consequences for the parental species involved (wasted reproductive effort), and has raised concerns for species conservation. This study evaluates the relative fitness of previously documented butterflyfish hybrids of the genus Chaetodon from the Indo-Pacific suture zone at Christmas Island. Histological examination confirmed the reproductive viability of Chaetodon hybrids. Examination of liver lipid content showed that hybrid body condition was not significantly different from parent species body condition. Lastly, size at age data revealed no difference in growth rates and asymptotic length between hybrids and parent species. Based on the traits measured in this study, naturally occurring hybrids of Chaetodon butterflyfishes have similar fitness to their parental species, and are unlikely to supplant parental species under current environmental conditions at the suture zone. However, given sufficient fitness and ongoing genetic exchange between the respective parental species, hybrids are likely to persist within the suture zone
ABCC5, a Gene That Influences the Anterior Chamber Depth, Is Associated with Primary Angle Closure Glaucoma
Anterior chamber depth (ACD) is a key anatomical risk factor for primary angle closure glaucoma (PACG). We conducted a genome-wide association study (GWAS) on ACD to discover novel genes for PACG on a total of 5,308 population-based individuals of Asian descent. Genome-wide significant association was observed at a sequence variant within ABCC5 (rs1401999; per-allele effect size = -0.045 mm, P = 8.17×10-9). This locus was associated with an increase in risk of PACG in a separate case-control study of 4,276 PACG cases and 18,801 controls (per-allele OR = 1.13 [95% CI: 1.06-1.22], P = 0.00046). The association was strengthened when a sub-group of controls with open angles were included in the analysis (per-allele OR = 1.30, P = 7.45×10-9; 3,458 cases vs. 3,831 controls). Our findings suggest that the increase in PACG risk could in part be mediated by genetic sequence variants influencing anterior chamber dimensions
A proposed decision support tool for prioritising conservation planning of Southeast Asian seagrass meadows: Combined approaches based on ecosystem services and vulnerability analyses
AbstractSeagrass habitats provide a range of goods and benefits to coastal communities by supporting ecosystem functioning, food provisioning, and cultural values. However, they are at risk worldwide from anthropogenic activities, climate change impacts and limited resources, which hamper efforts to protect them. Effective conservation planning requires prioritisation of sites based on multiple factors, including their relative value and vulnerability (VU). The current study examines the efficacy of combining two well-established approaches – ecosystem service assessments and habitat VU analyses – to test a method for determining conservation priority for selected seagrass meadows in Southeast Asia. Seven seagrass meadows around Southeast Asia were selected and scored by the authors based on (1) the cumulative contribution of 12 ecosystem services (ES) and the condition of the meadows, (2) VU from 16 anthropogenic threats, which were each ranked against five factors (spatial scale, frequency, functional impact, resistance and recovery time) and (3) the combination of the two approaches to create a single numerical index. Prioritisation of sites differed when meadows were scored solely for the ES they provide, compared to how vulnerable they are to anthropogenic threats. The new combined analysis brought the two metrics together to give conservation priority to sites where management intervention will yield maximum conservation benefits from conservation effort, and resulted in the prioritisation of three sites: Barrang Lompo (Indonesia), Cape Bolinao (Philippines) and Beting Tanjung Kupang (Malaysia). This method is easy to use and does not require great technical expertise. It is also auditable, allowing for clear and transparent understanding of decision-making process.</jats:p
Seagrass in Southeast Asia: A review of status and knowledge gaps, and a road map for conservation
AbstractSoutheast Asia has the highest diversity of seagrass species and habitat types, but basic information on seagrass habitats is still lacking. This review examines the known distribution, extent, species diversity, and research and knowledge gaps of seagrasses in Southeast Asia by biogeographic region of the Marine Ecoregions of the World (MEOW). The extent of seagrass meadows in Southeast Asia is ~36,762.6 km2but this is likely an underestimate as some ecoregions were not well-represented and updated information was lacking. There is a paucity of information from the Western Coral Triangle Province, with no areal extent data available for the Indonesian regions of Kalimantan, Central and Southeast Sulawesi, the Maluku Islands, and West Papua. Regional research output has increased in the last two decades, with a trend towards more experimental, rather than descriptive research. However, there are knowledge gaps in socio-cultural-economic themed research, despite growing awareness of the importance of seagrass-human relationships in this region. Obstacles to advancing seagrass research, knowledge and conservation are rooted in either lack of expertise and training or the failure of effective management and policies. We propose a roadmap for seagrass conservation, with suggested solutions, including 1) encouraging collaboration between research institutions and scientists in the region to build capacity and share knowledge; 2) engaging with policymakers and governments to encourage science-based policies; 3) engaging with communities to raise awareness and foster stewardship of seagrass in the region.</jats:p
Distribution, Temporal Change, and Conservation Status of Tropical Seagrass Beds in Southeast Asia: 2000–2020
Although Southeast Asia is a hotspot of global seagrass diversity, there are considerable information gaps in the distribution of seagrass beds. Broad-scale seagrass distribution has not been updated in the global seagrass database by UNEP-WCMC since 2000, although studies on seagrasses have been undertaken intensively in each region. Here we analyze the recent distribution of tropical seagrass beds, their temporal changes, causes of decline and conservation status in Southeast Asia (plus southern mainland China, Taiwan and Ryukyu Island of Japan) using data collected after 2000. Based on the 195 literature published since 2000, we identified 1,259 point data and 1,461 polygon data showing the distribution of seagrass beds. A large discrepancy was found in the seagrass bed distribution between our updated data and the UNEP-WCMC database, mostly due to inaccurate and low resolution location information in the latter. Temporal changes in seagrass bed area analyzed for 68 sites in nine countries/regions demonstrated that more than 60% of seagrass beds declined at an average rate of 10.9% year–1, whereas 20% of beds increased at an average rate of 8.1% year–1, leading to an overall average decline of 4.7% year–1. Various types of human-induced threats were reported as causes for the decline, including coastal development, fisheries/aquaculture, and natural factors such as typhoons and tsunamis. The percentage of seagrass beds covered with existing marine protected areas (MPAs) varied greatly among countries/regions, from less than 1% in Brunei Darussalam and Singapore to 100% in southern Japan. However, the degree of conservation regulation was not sufficient even in regions with higher MPA coverage. The percentage of seagrass beds within EBSAs (Ecologically and Biologically Significant Area determined by the Convention of Biological Diversity) was higher than that within MPAs because EBSAs cover a greater area than MPAs. Therefore, designating EBSAs as legally effective MPAs can greatly improve the conservation status of seagrass beds in Southeast Asia.</jats:p
Isolation and characterization of twenty microsatellite markers for the study of hybridization in butterflyfish of the genus Chaetodon
Twenty polymorphic microsatellite loci were developed via 454 sequencing for two hybridizing sister species of butterflyfish: the spot-band butterflyfish (Chaetodon punctatofasciatus) and peppered butterflyfish (Chaetodon guttatissimus), which are widely distributed in the Western Pacific and Indian Ocean, respectively. All loci were genotyped in samples collected from Christmas Island: C. guttatissimus (n = 25), C. punctatofasciatus (n = 17) and hybrids (n = 16). Mean alleles per locus (N a ) were: 9.05 for C. guttatissimus, 9.95 for C. punctatofasciatus and 9.45 for hybrids. Observed heterozygosity (H O ) ranged from 0.00 to 1.00 for C. guttatissimus; from 0.08 to 0.88 for C. punctatofasciatus; and from 0.19 to 0.94 for hybrids. Most loci conformed to Hardy–Weinberg expectations, were in linkage equilibrium, and did not contain null alleles. These markers will be useful for testing population genetic hypotheses including patterns of hybridization in this pair of butterflyfishes.Stefano R. Montanari, Michael G. Gardner, Jean-Paul A. Hobbs, Morgan S. Pratchett, Line K. Bay, Lynne van Herwerde
Hybridisation among groupers (genus Cephalopholis) at the eastern Indian Ocean suture zone: taxonomic and evolutionary implications
Hybridisation is a significant evolutionary process that until recently was considered rare in the marine environment. A suture zone in the eastern Indian Ocean is home to numerous hybridising sister species, providing an ideal opportunity to determine how hybridisation affects speciation and biodiversity in coral reef fishes. At this location, hybridisation between two grouper (Epinephelidae) species: Cephalopholis urodeta (Pacific Ocean) and C. nigripinnis (Indian Ocean) was investigated to determine the genetic basis of hybridisation and to compare the ecology and life history of hybrids and their parent species. This approach aimed to provide insights into the taxonomic and evolutionary consequences of hybridisation. Despite clear phenotypic differences, multiple molecular markers revealed hybrids, and their parent species were genetically homogenous within and (thousands of kilometres) outside of the hybrid zone. Hybrids were at least as fit as their parent species (in terms of growth, reproduction, and abundance) and were observed in a broad range of intermediate phenotypes. The two species appear to be interbreeding at Christmas Island due to inherent biological and ecological compatibilities, and the lack of genetic structure may be explained by three potential scenarios: (1) hybridisation and introgression; (2) discordance between morphology and genetics; and (3) incomplete lineage sorting. Further molecular analyses are necessary to discriminate these scenarios. Regardless of which applies, C. urodeta and C. nigripinnis are unlikely to evolve in reproductive isolation as they cohabit where they are common (Christmas Island) and will source congeneric mates where they are rare (Cocos Keeling Islands). Our results add to the growing body of evidence that hybridisation among coral reef fishes is a dynamic evolutionary factor. © 2016 Springer-Verlag Berlin Heidelberg