Displaying publications 21 - 40 of 995 in total

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  1. Fulltext Diversity of microfungi in sandy beach soil of teluk aling, pulau pinang
    Zakaria L, Yee TL, Zakaria M, Salleh B
    Trop Life Sci Res, 2011 May;22(1):71-80.
    PMID: 24575210 MyJurnal
    A total of 82 isolates of microfungi were isolated from 6 sandy soil samples collected from Teluk Aling beach, Pulau Pinang. The soil microfungi were isolated by using direct isolation, debris isolation and soil dilution techniques. Based on morphological characteristics, seven genera of microfungi were identified namely, Fusarium (42%), Aspergillus (24%), Trichoderma (13%), Curvularia (9%), Colletotrichum (6%), Helminthosporium (4%) and Penicillium (2%). The most common species isolated was Fusarium solani followed by Fusarium semitecum, Aspergillus niger, Trichoderma viride, Curvularia clavata, Curvularia lunata, Helminthosporium velutinum, Colletotrichum sp. and Penicillium chrysogenum. From the present study, it appears that the sandy beach contains a microfungi reservoir comprising of a variety of genera which contributes significantly to the ecological functioning of a marine ecosystem.
    Matched MeSH terms: Ecosystem
  2. Fulltext Repeated Evaluations of Testes and Semen Characteristics in Two Binturongs (Arctictis binturong)
    Zainuddin ZZ, Sipangkui S, Farqhan Kelana M, Chee YK, Tarmizi MRM, Comizzoli P
    Front Vet Sci, 2021;8:658573.
    PMID: 33778042 DOI: 10.3389/fvets.2021.658573
    The binturong is a medium size carnivore belonging to the Viverrid family that lives in dense forests of South-East Asia. In addition to the protection of this vulnerable species in its natural habitat (in situ), conservation breeding efforts (ex situ) aim at maintaining a good genetic diversity while increasing the number of individuals to reinforce wild populations. Both approaches require a solid understanding of binturong's basic biology. However, there is still a lack of precise information about reproduction. The objective of this brief research report was to analyze testicular sizes and semen characteristics at different times of the year to better understand the reproductive physiology and inform future conservation efforts. A secondary objective was to describe sperm cryotolerance for the first time in that species. Examinations of testes and semen collections were conducted on two adult males. While testicular measurements were relatively constant across multiple examinations, semen characteristics (volume, viability, sperm concentrations, sperm motility) varied between samples. However, incidence of sperm morphological abnormalities was consistently high. Sperm cryotolerance appeared to be poor but further studies are warranted. The present dataset will be useful for future research on binturong reproduction and for the development of assisted reproductive techniques and biobanking of germplasms in that species.
    Matched MeSH terms: Ecosystem
  3. Occurrence and potential risk of organophosphorus pesticides in urbanised Linggi River, Negeri Sembilan, Malaysia
    Zainuddin AH, Wee SY, Aris AZ
    Environ Geochem Health, 2020 Nov;42(11):3703-3715.
    PMID: 32488800 DOI: 10.1007/s10653-020-00604-4
    The application of organophosphorus pesticides (OPPs) increased gradually because of the rise in global food demand that triggered the agriculture sector to increase the production, leading to OPP residues in the surface water. This study elucidated the presence of OPPs and estimated its ecological risk in the riverine ecosystem of the urbanised Linggi River, Negeri Sembilan, Malaysia. The OPP concentration in surface water was determined using solid-phase extraction method and high-performance liquid chromatography coupled with diode array detection. Further, the ecological risk was estimated by using the risk quotient (RQ) method. The three OPPs, i.e. chlorpyrifos, diazinon, and quinalphos were detected with mean concentrations of 0.0275 µg/L, 0.0328 µg/L, and 0.0362 µg/L, respectively. The OPPs were at high risk (in general and worst cases) under acute exposure. The estimated risk of diazinon was observed as medium for general (RQm = 0.5857) and high for worst cases (RQex = 4.4678). Notably, the estimated risk for chlorpyrifos was high for both general and worst cases (RQm = 1.9643 and RQex = 11.5643) towards the aquatic ecosystem of the Linggi River. Chronic risk of quinalphos remains unknown because of the absence of toxicity endpoints. This study presented clear knowledge regarding OPP contamination and possible risk for aquatic ecosystems. Hence, OPPs should be listed as one of the main priority contaminants in pesticide mitigation management in the future.
    Matched MeSH terms: Ecosystem
  4. Occurrence, potential sources and ecological risk estimation of microplastic towards coastal and estuarine zones in Malaysia
    Zainuddin AH, Aris AZ, Zaki MRM, Yusoff FM, Wee SY
    Mar Pollut Bull, 2022 Jan;174:113282.
    PMID: 34995888 DOI: 10.1016/j.marpolbul.2021.113282
    Extensive global plastic production has led to microplastic (MP) pollution of marine ecosystems. This study analysed the abundance of MPs in the surface water of tropical coastal and estuarine zones in Malaysia affected by rapid urbanisation and intense human activity. It also estimated the risk posed by MPs to the marine environment. Mean MP abundance ranged from 2.10 to 6.80 particles/L. Fourier-transform infrared spectroscopic analysis found that the MP polymers were dominated by cellophane (54%), followed by polyester (33%) and polyethylene (2%). The risk posed by MPs was estimated with the risk quotient (RQ) method which found no potential ecological risk to both coastal and estuarine areas (RQ 
    Matched MeSH terms: Ecosystem
  5. Occurrence, distribution, and ecological risk of bisphenol analogues in marine ecosystem of urbanized coast and estuary
    Zainuddin AH, Roslan MQJ, Razak MR, Yusoff FM, Haron DEM, Aris AZ
    Mar Pollut Bull, 2023 Jul;192:115019.
    PMID: 37201347 DOI: 10.1016/j.marpolbul.2023.115019
    Bisphenol analogues are prevalent globally because of rampant usage and imprecise processing techniques, prompting alerts about environmental and health hazards. The method employed in this study by solid phase extraction (SPE) and liquid chromatography-tandem quadrupole mass spectrometer (LC-MS/MS) for both quantification and qualitative analysis of the bisphenol compounds in the surface water samples. The coastal and estuarine surface water of Port Dickson and Lukut ranges from 1.32 ng/L to 1890.51 ng/L of bisphenol analogues. BPF mean concentration at 1143.88 ng/L is the highest, followed by BPA and BPS at 59.01 ng/L and 10.96 ng/L, respectively. Based on RQm for bisphenol analogues, the highest for BPF at 2.49 (RQ > 1, high risk), followed by BPS at 0.12 (0.1 
    Matched MeSH terms: Ecosystem*
  6. Fulltext Determination of Trophic Structure in Selected Freshwater Ecosystems by using Stable Isotope Analysis
    Zainordin 'F, Ab Hamid S
    Trop Life Sci Res, 2017 Jul;28(2):9-29.
    PMID: 28890758 MyJurnal DOI: 10.21315/tlsr2017.28.2.2
    Stable isotope analysis has been used extensively to establish trophic relationships in many ecosystems. Present study utilised stable isotope signatures of carbon and nitrogen to identify trophic structure of aquatic food web in river and rice field ecosystems in Perak, northern peninsular Malaysia. The mean δ(13)C values of all producers ranged from -35.29 ± 0.21 to -26.00 ± 0.050‰. The greatest δ(15)N values noted was in zenarchopterid fish with 9.68 ± 0.020‰. The δ(15)N values of aquatic insects ranged between 2.59 ± 0.107 in Elmidae (Coleoptera) and 8.11 ± 0.022‰ in Nepidae (Hemiptera). Correspondingly, with all the δ(13)C and δ(15)N values recorded, it can be deduced that there are four trophic levels existed in the freshwater ecosystems which started with the producer (plants), followed by primary consumer (aquatic insects and non-predatory fish), secondary consumer (invertebrate predators) and lastly tertiary consumer (vertebrate predators).
    Matched MeSH terms: Ecosystem
  7. Fulltext Assessing a megadiverse but poorly known community of fishes in a tropical mangrove estuary through environmental DNA (eDNA) metabarcoding
    Zainal Abidin DH, Mohd Nor SA, Lavoué S, A Rahim M, Mohammed Akib NA
    Sci Rep, 2022 Sep 29;12(1):16346.
    PMID: 36175455 DOI: 10.1038/s41598-022-19954-3
    Biodiversity surveys are crucial for monitoring the status of threatened aquatic ecosystems, such as tropical estuaries and mangroves. Conventional monitoring methods are intrusive, time-consuming, substantially expensive, and often provide only rough estimates in complex habitats. An advanced monitoring approach, environmental DNA (eDNA) metabarcoding, is promising, although only few applications in tropical mangrove estuaries have been reported. In this study, we explore the advantages and limitations of an eDNA metabarcoding survey on the fish community of the Merbok Estuary (Peninsular Malaysia). COI and 12S eDNA metabarcoding assays collectively detected 178 species from 127 genera, 68 families, and 25 orders. Using this approach, significantly more species have been detected in the Merbok Estuary over the past decade (2010-2019) than in conventional surveys, including several species of conservation importance. However, we highlight three limitations: (1) in the absence of a comprehensive reference database the identities of several species are unresolved; (2) some of the previously documented specimen-based diversity was not captured by the current method, perhaps as a consequence of PCR primer specificity, and (3) the detection of non-resident species-stenohaline freshwater taxa (e.g., cyprinids, channids, osphronemids) and marine coral reef taxa (e.g., holocentrids, some syngnathids and sharks), not known to frequent estuaries, leading to the supposition that their DNA have drifted into the estuary through water movements. The community analysis revealed that fish diversity along the Merbok Estuary is not homogenous, with the upstream more diverse than further downstream. This could be due to the different landscapes or degree of anthropogenic influences along the estuary. In summary, we demonstrated the practicality of eDNA metabarcoding in assessing fish community and structure within a complex and rich tropical environment within a short sampling period. However, some limitations need to be considered and addressed to fully exploit the efficacy of this approach.
    Matched MeSH terms: Ecosystem
  8. Fulltext DNA-based taxonomy of a mangrove-associated community of fishes in Southeast Asia
    Zainal Abidin DH, Mohd Nor SA, Lavoué S, A Rahim M, Jamaludin NA, Mohammed Akib NA
    Sci Rep, 2021 Sep 07;11(1):17800.
    PMID: 34493747 DOI: 10.1038/s41598-021-97324-1
    The Merbok Estuary comprises one of the largest remaining mangrove forests in Peninsular Malaysia. Its value is significant as it provides important services to local and global communities. It also offers a unique opportunity to study the structure and functioning of mangrove ecosystems. However, its biodiversity is still partially inventoried, limiting its research value. A recent checklist based on morphological examination, reported 138 fish species residing, frequenting or subject to entering the Merbok Estuary. In this work, we reassessed the fish diversity of the Merbok Estuary by DNA barcoding 350 specimens assignable to 134 species initially identified based on morphology. Our results consistently revealed the presence of 139 Molecular Operational Taxonomic Units (MOTUs). 123 of them are congruent with morphology-based species delimitation (one species = one MOTU). In two cases, two morphological species share the same MOTU (two species = one MOTU), while we unveiled cryptic diversity (i.e. COI-based genetic variability > 2%) within seven other species (one species = two MOTUs), calling for further taxonomic investigations. This study provides a comprehensive core-list of fish taxa in Merbok Estuary, demonstrating the advantages of combining morphological and molecular evidence to describe diverse but still poorly studied tropical fish communities. It also delivers a large DNA reference collection for brackish fishes occurring in this region which will facilitate further biodiversity-oriented research studies and management activities.
    Matched MeSH terms: Ecosystem*
  9. Fulltext An automated solid waste detection using the optimized YOLO model for riverine management
    Zailan NA, Azizan MM, Hasikin K, Mohd Khairuddin AS, Khairuddin U
    Front Public Health, 2022;10:907280.
    PMID: 36033781 DOI: 10.3389/fpubh.2022.907280
    Due to urbanization, solid waste pollution is an increasing concern for rivers, possibly threatening human health, ecological integrity, and ecosystem services. Riverine management in urban landscapes requires best management practices since the river is a vital component in urban ecological civilization, and it is very imperative to synchronize the connection between urban development and river protection. Thus, the implementation of proper and innovative measures is vital to control garbage pollution in the rivers. A robot that cleans the waste autonomously can be a good solution to manage river pollution efficiently. Identifying and obtaining precise positions of garbage are the most crucial parts of the visual system for a cleaning robot. Computer vision has paved a way for computers to understand and interpret the surrounding objects. The development of an accurate computer vision system is a vital step toward a robotic platform since this is the front-end observation system before consequent manipulation and grasping systems. The scope of this work is to acquire visual information about floating garbage on the river, which is vital in building a robotic platform for river cleaning robots. In this paper, an automated detection system based on the improved You Only Look Once (YOLO) model is developed to detect floating garbage under various conditions, such as fluctuating illumination, complex background, and occlusion. The proposed object detection model has been shown to promote rapid convergence which improves the training time duration. In addition, the proposed object detection model has been shown to improve detection accuracy by strengthening the non-linear feature extraction process. The results showed that the proposed model achieved a mean average precision (mAP) value of 89%. Hence, the proposed model is considered feasible for identifying five classes of garbage, such as plastic bottles, aluminum cans, plastic bags, styrofoam, and plastic containers.
    Matched MeSH terms: Ecosystem*
  10. Towards online surface water quality monitoring technology: A review
    Zaidi Farouk MIH, Jamil Z, Abdul Latip MF
    Environ Res, 2023 Dec 01;238(Pt 1):117147.
    PMID: 37716398 DOI: 10.1016/j.envres.2023.117147
    The exponential growth of human population and anthropogenic activities have led to the increase of global surface water contamination especially in river, lakes and ocean. Safe and clean surface water sources are crucial to human health and well-being, aquatic ecosystem, environment and economy. Thus, water monitoring is vital to ensure minimal and controllable contamination in the water sources. The conventional surface water monitoring method involves collecting samples on site and then testing them in the laboratory, which is time-consuming and not able to provide real-time water quality data. In addition, it involves many manpower and resources, costly and lack of integration. These make surface water quality monitoring more challenging. The incorporation of Internet of Things (IoT) and smart technology has contributed to the improvement of monitoring system. There are different approaches in the development and implementation of online surface water quality monitoring system to provide real-time data collection with lower operating cost. This paper reviews the sensors and system developed for the online surface water quality monitoring system in the previous studies. The calibration and validation of the sensors, and challenges in the design and development of online surface water quality monitoring system are also discussed.
    Matched MeSH terms: Ecosystem*
  11. Spatial and temporal variations in Strombus canarium (Gastropoda: Strombidae) abundance at Merambong Seagrass Bed, Malaysia
    Zaidi Che Cob, Aziz Arshad, Japar Sidik Bujang, Mazlan Abd Ghaffar
    Sains Malaysiana, 2014;43:503-511.
    The abundance of marine benthic organisms often exhibits distinct distributional patterns, which is generally governed by many physical and biological factors specific to the habitat. In this study, the spatial and temporal variations in abundance of the dog conch, Strombus canarium Linnaeus 1758, a commercially important marine gastropod, was investigated. Assessment of conch abundance at Merambong seagrass bed, Malaysia, was conducted using a transect belt method. Sampling stations were randomly selected and environmental parameters associated with the habitat were recorded. The species showed distinct spatial distributional pattern. Conch densities were significantly higher in sheltered areas, mainly in mixed seagrass bed dominated by Halophila spp. and with high sediment organic content. The densities were relatively very low in areas dominated by the tape seagrass, Enhalus acoroides. The species studied also showed distinct temporal variation in abundance. The abundance value was seasonally varied with highest density recorded during the wet monsoon season (p<0.05). The densities were otherwise very low during the dry season, except for a slight peak in July. Since the conch is a very important fishery species within the Johor Straits and regulations on their harvesting is still lacking, this information would be very important for their sustainable management.
    Matched MeSH terms: Ecosystem
  12. Fulltext A comprehensive review of various approaches for treatment of tertiary wastewater with emerging contaminants: what do we know?
    Zahmatkesh S, Bokhari A, Karimian M, Zahra MMA, Sillanpää M, Panchal H, et al.
    Environ Monit Assess, 2022 Oct 14;194(12):884.
    PMID: 36239735 DOI: 10.1007/s10661-022-10503-z
    In the last few decades, environmental contaminants (ECs) have been introduced into the environment at an alarming rate. There is a risk to human health and aquatic ecosystems from trace levels of emerging contaminants, including hospital wastewater (HPWW), cosmetics, personal care products, endocrine system disruptors, and their transformation products. Despite the fact that these pollutants have been introduced or detected relatively recently, information about their characteristics, actions, and impacts is limited, as are the technologies to eliminate them efficiently. A wastewater recycling system is capable of providing irrigation water for crops and municipal sewage treatment, so removing ECs before wastewater reuse is essential. Water treatment processes containing advanced ions of biotic origin and ECs of biotic origin are highly recommended for contaminants. This study introduces the fundamentals of the treatment of tertiary wastewater, including membranes, filtration, UV (ultraviolet) irradiation, ozonation, chlorination, advanced oxidation processes, activated carbon (AC), and algae. Next, a detailed description of recent developments and innovations in each component of the emerging contaminant removal process is provided.
    Matched MeSH terms: Ecosystem
  13. Fulltext Partial mtDNA sequencing data of vulnerable Cephalopachus bancanus from the Malaysian Borneo
    Zahidin MA, Jalil NA, Naharuddin NM, Abd Rahman MR, Gani M, Abdullah MT
    Data Brief, 2019 Aug;25:104133.
    PMID: 31321260 DOI: 10.1016/j.dib.2019.104133
    Tarsier is an endangered nocturnal primate in the family Tarsiidae and is an endemic to Sundaic islands of Philippine (Carlito syrichta), Sulawesi (Tarsius tarsier-complex) and Borneo (Cephalopachus bancanus). Recent records indicated that most molecular studies were done on the Eastern Tarsier and little information for the other group of tarsiers. Here, we present a partial cytochrome b data set of C. bancanus in Sarawak, Malaysian Borneo. Standard mist nets were deployed at strategic locations in various habitat types. A total of 18 individuals were caught, measured and weighed. Approximately, 2 × 2 mm of tissue samples were taken and preserved in molecular grade alcohol. Out of 18, only 11 samples were screened with partial mtDNA (cytochrome b) and the DNA sequences were registered in the GenBank (accession numbers: KY794797-KY794807). Phylogenetic trees were constructed with 20 additional mtDNA sequences downloaded from GenBank. The data are valuable for the management authorities to regulate the type of management units for the metapopulation to sustain population genetics integrity of tarsiers in the range countries across the Sunda Shelf.
    Matched MeSH terms: Ecosystem
  14. Exploring nanocellulose frontiers: A comprehensive review of its extraction, properties, and pioneering applications in the automotive and biomedical industries
    Yusuf J, Sapuan SM, Ansari MA, Siddiqui VU, Jamal T, Ilyas RA, et al.
    Int J Biol Macromol, 2024 Jan;255:128121.
    PMID: 37984579 DOI: 10.1016/j.ijbiomac.2023.128121
    Material is an inseparable entity for humans to serve different purposes. However, synthetic polymers represent a major category of anthropogenic pollutants with detrimental impacts on natural ecosystems. This escalating environmental issue is characterized by the accumulation of non-biodegradable plastic materials, which pose serious threats to the health of our planet's ecosystem. Cellulose is becoming a focal point for many researchers due to its high availability. It has been used to serve various purposes. Recent scientific advancements have unveiled innovative prospects for the utilization of nanocellulose within the area of advanced science. This comprehensive review investigates deeply into the field of nanocellulose, explaining the methodologies employed in separating nanocellulose from cellulose. It also explains upon two intricately examined applications that emphasize the pivotal role of nanocellulose in nanocomposites. The initial instance pertains to the automotive sector, encompassing cutting-edge applications in electric vehicle (EV) batteries, while the second exemplifies the use of nanocellulose in the field of biomedical applications like otorhinolaryngology, ophthalmology, and wound dressing. This review aims to provide comprehensive information starting from the definitions, identifying the sources of the nanocellulose and its extraction, and ending with the recent applications in the emerging field such as energy storage and biomedical applications.
    Matched MeSH terms: Ecosystem*
  15. Microhabitat Factors Influenced the Prevalence of Pathogenic Leptospira spp. in Small Mammal Host
    Yusof MA, Mohd-Taib FS, Ishak SN, Md-Nor S, Md-Sah SA, Mohamed NZ, et al.
    Ecohealth, 2019 06;16(2):260-274.
    PMID: 31124020 DOI: 10.1007/s10393-019-01419-1
    Leptospirosis, a widespread zoonotic disease, is a public health problem, especially in major urban centres, and is mainly reported to be associated with rats. In Malaysia, focus has been primarily given to the Leptospira prevalence in rodents per se, but there is lack of information on the microhabitat structure of the outbreak areas. We aimed to determine the diversity of small mammal species, microhabitat types, and their prevalence of pathogenic Leptospira spp. in the outbreak areas, which were categorized as urban, semi-urban, and recreational forests. Sampling involved deploying 100 to 300 live traps at each study site. Kidney samples were extracted from selected individuals, for screening of pathogenic Leptospira spp. by PCR. Out of 537 individuals from 15 small mammal species captured, 4 species were recorded from urban, 13 from semi-urban, and 11 from recreational forest sites. From 389 individuals screened, 58 were tested positive for pathogenic Leptospira. Recreational forests recorded the highest prevalence with 19.4% (n = 93), followed by urban, 16.6% (n = 163) and semi-urban sites with 9.8% (n = 133). Seven rodent species were tested positive for pathogenic Leptospira from all areas. R. norvegicus was found to harbour the highest prevalence (66.7%) in urban, R. rattus (53.8%) in semi-urban, whereby M. whiteheadi (44.4%) in recreational forest sites. Microhabitat analysis revealed that rubbish quantity contributed especially strongly to a high prevalence of Leptospira. This study contributes to understanding of the host and microhabitat preferences of Leptospira, which is important in controlling the spread of this disease in human's landscapes.
    Matched MeSH terms: Ecosystem*
  16. First evidence of microplastic pollution in the surface water of Malaysian Marine Park islands, South China Sea during COVID-19
    Yusof KMKK, Anuar ST, Mohamad Y, Jaafar M, Mohamad N, Bachok Z, et al.
    Mar Pollut Bull, 2023 Sep;194(Pt B):115268.
    PMID: 37451046 DOI: 10.1016/j.marpolbul.2023.115268
    Malaysia is bounded by the South China Sea with many islands that support species megadiversity and coral reef ecosystems. This study investigates the distribution of microplastics (MPs) in the surface water around the four marine park islands (Perhentian, Redang, Kapas, and Tenggol) during COVID-19. The global pandemic has reset human activities, impacting the environment while possibly reducing anthropogenic contributions of microplastic pollution near the South China Sea islands. It was found that Pulau Perhentian recorded the most abundance of MPs (588.33 ± 111.77 items/L), followed by Pulau Redang (314.67 ± 58.08 items/L), Pulau Kapas (359.8 ± 87.70 items/L) and Pulau Tenggol (294.33 ± 101.64 items/L). Kruskal-Wallis analysis indicates a significant difference in total MPs abundance between islands. There are moderate correlations between salinity, pH, temperature and MPs variability. Among these parameters, only temperature is significant (p 
    Matched MeSH terms: Ecosystem
  17. Fulltext Ant mosaics in Bornean primary rain forest high canopy depend on spatial scale, time of day, and sampling method
    Yusah KM, Foster WA, Reynolds G, Fayle TM
    PeerJ, 2018;6:e4231.
    PMID: 29423344 DOI: 10.7717/peerj.4231
    Background: Competitive interactions in biological communities can be thought of as giving rise to "assembly rules" that dictate the species that are able to co-exist. Ant communities in tropical canopies often display a particular pattern, an "ant mosaic", in which competition between dominant ant species results in a patchwork of mutually exclusive territories. Although ant mosaics have been well-documented in plantation landscapes, their presence in pristine tropical forests remained contentious until recently. Here we assess presence of ant mosaics in a hitherto under-investigated forest stratum, the emergent trees of the high canopy in primary tropical rain forest, and explore how the strength of any ant mosaics is affected by spatial scale, time of day, and sampling method.

    Methods: To test whether these factors might impact the detection of ant mosaics in pristine habitats, we sampled ant communities from emergent trees, which rise above the highest canopy layers in lowland dipterocarp rain forests in North Borneo (38.8-60.2 m), using both baiting and insecticide fogging. Critically, we restricted sampling to only the canopy of each focal tree. For baiting, we carried out sampling during both the day and the night. We used null models of species co-occurrence to assess patterns of segregation at within-tree and between-tree scales.

    Results: The numerically dominant ant species on the emergent trees sampled formed a diverse community, with differences in the identity of dominant species between times of day and sampling methods. Between trees, we found patterns of ant species segregation consistent with the existence of ant mosaics using both methods. Within trees, fogged ants were segregated, while baited ants were segregated only at night.

    Discussion: We conclude that ant mosaics are present within the emergent trees of the high canopy of tropical rain forest in Malaysian Borneo, and that sampling technique, spatial scale, and time of day interact to determine observed patterns of segregation. Restricting sampling to only emergent trees reveals segregatory patterns not observed in ground-based studies, confirming previous observations of stronger segregation with increasing height in the canopy.

    Matched MeSH terms: Ecosystem
  18. The effects of drainage basin geomorphometry on minimum low flow discharge: the study of small watershed in Kelang River Valley in Peninsular Malaysia
    Yunus AJ, Nakagoshi N, Salleh KO
    J Environ Sci (China), 2003 Mar;15(2):249-62.
    PMID: 12765268
    This study investigate the relationships between geomorphometric properties and the minimum low flow discharge of undisturbed drainage basins in the Taman Bukit Cahaya Seri Alam Forest Reserve, Peninsular Malaysia. The drainage basins selected were third-order basins so as to facilitate a common base for sampling and performing an unbiased statistical analyses. Three levels of relationships were observed in the study. Significant relationships existed between the geomorphometric properties as shown by the correlation network analysis; secondly, individual geomorphometric properties were observed to influence minimum flow discharge; and finally, the multiple regression model set up showed that minimum flow discharge (Q min) was dependent of basin area (AU), stream length (LS), maximum relief (Hmax), average relief (HAV) and stream frequency (SF). These findings further enforced other studies of this nature that drainage basins were dynamic and functional entities whose operations were governed by complex interrelationships occurring within the basins. Changes to any of the geomorphometric properties would influence their role as basin regulators thus influencing a change in basin response. In the case of the basin's minimum low flow, a change in any of the properties considered in the regression model influenced the "time to peak" of flow. A shorter time period would mean higher discharge, which is generally considered the prerequisite to flooding. This research also conclude that the role of geomorphometric properties to control the water supply within the stream through out the year even though during the drought and less precipitations months. Drainage basins are sensitive entities and any deteriorations involve will generate reciprocals and response to the water supply as well as the habitat within the areas.
    Matched MeSH terms: Ecosystem*
  19. Litter quality and stream physicochemical properties drive global invertebrate effects on instream litter decomposition
    Yue K, De Frenne P, Van Meerbeek K, Ferreira V, Fornara DA, Wu Q, et al.
    Biol Rev Camb Philos Soc, 2022 Dec;97(6):2023-2038.
    PMID: 35811333 DOI: 10.1111/brv.12880
    Plant litter is the major source of energy and nutrients in stream ecosystems and its decomposition is vital for ecosystem nutrient cycling and functioning. Invertebrates are key contributors to instream litter decomposition, yet quantification of their effects and drivers at the global scale remains lacking. Here, we systematically synthesized data comprising 2707 observations from 141 studies of stream litter decomposition to assess the contribution and drivers of invertebrates to the decomposition process across the globe. We found that (1) the presence of invertebrates enhanced instream litter decomposition globally by an average of 74%; (2) initial litter quality and stream water physicochemical properties were equal drivers of invertebrate effects on litter decomposition, while invertebrate effects on litter decomposition were not affected by climatic region, mesh size of coarse-mesh bags or mycorrhizal association of plants providing leaf litter; and (3) the contribution of invertebrates to litter decomposition was greatest during the early stages of litter mass loss (0-20%). Our results, besides quantitatively synthesizing the global pattern of invertebrate contribution to instream litter decomposition, highlight the most significant effects of invertebrates on litter decomposition at early rather than middle or late decomposition stages, providing support for the inclusion of invertebrates in global dynamic models of litter decomposition in streams to explore mechanisms and impacts of terrestrial, aquatic, and atmospheric carbon fluxes.
    Matched MeSH terms: Ecosystem*
  20. Form and habit in species of malleus (including the "hammer oysters") with comparative observations on Isognomon isognomon
    Yonge CM
    Biol. Bull., 1968 Oct;135(2):378-405.
    PMID: 28368764 DOI: 10.2307/1539789
    1. Study of the structure and mode of life of Malleus regula provides the basis for consideration of the "hammer" species, M. malleus and M. albus.
    2. M. regula occurs byssally attached, vertically disposed on rocky substrates associated with mud and is widely distributed in the tropical Indo-Pacific.
    3. The distal two-thirds of the elongated shell is exclusively prismatic. By means of special pallial retractors the mantle lobes can be withdrawn within the nacreous region.
    4. The massive opisthodetic ligament has a short secondary extension of fusion layer.
    5. A promyal chamber on the right side proximal to the adductor increases water flow into the exhalant chamber.
    6. The long filibranch ctenidia provide a vertically extended food-collecting surface.
    7. The foot is concerned with planting of the massive byssus which emerges through a notch in the right valve but on the under ( i.e., dorsal) surface. There is also a unique and very long accessory foot, ventrally grooved, everywhere ciliated and in constant writhing activity due to blood pressure and intrinsic muscle. Moving freely throughout the lower mantle cavity it can only be concerned with cleansing.
    8. Pseudofaeces are ejected from the distal tip of the mantle cavity.
    9. M. malleus, the black hammer shell, occurs vertically embedded in coarse sand or sandy gravel. Byssus threads are attached to fragments within the substrate. The great anterior and posterior elongations of the hinge line (also exclusively prismatic) are separated by the byssal notch (now affecting both valves).
    10. Shells are usually excessively irregular due to the great exposure to damage and the almost unlimited powers of rapid repair by the three pallial extensions.
    11. M. albus, the white hammer shell, is stouter and inhabits muddy sand. During growth it loses the byssus with reduction of the foot and byssal retractors and closure of the byssal notch. The accessory foot is not affected. The animal becomes anchored in the substrate exclusively by the anterior and posterior extensions of the shell.
    12. Description of the typically rounded Isognomon ephippium leads to that of the elongated I. isognomon which occupies precisely the same habitat as M. regula.
    13. It lacks the pallial retractors, promyal chamber and accessory foot of Malleus, the nacreous region is more extended distally and the ligament is multivincular (the formation of which is discussed), producing some posterior, but never any anterior, extension of the hinge line.
    14. A remarkably dense mixed bed of M. regula and I. isognomon in Darvel Bay, Sabah (Borneo), is described. Different spawning periods, by preventing competition during settlement, may account for this complete intermixing of sympatric species, which, however, are generalized herbivores where numbers are not limited by food supply.
    15. From a basic epifaunal habit (Pteria, Isognomon, M. regula), members of the Pteriacea have become adapted for infaunal life within sponges (Vulsella, Crenatula) or within soft substrates ( M. malleus, M. alba and the Pinnidae).
    16. There is final discussion about elongation in monomyarians, i.e., in the genus Malleus and in I. isognomon.
    Matched MeSH terms: Ecosystem
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