Tupaia Glis Research Articles

Socio-environmental factors associated with small mammal assemblage and Leptospira prevalence in Suburban Areas of Terengganu, Malaysia

Objective: To examine the socio-environmental factors associated with the assemblage of small mammals and the prevalence of Leptospira pathogen in poor suburban communities of Terengganu, Malaysia. Methods: We trapped small mammals from 119 trapping points scattered around three suburban communities of Terengganu using sausage-baited live traps. On the average, we set up five traps for three nights at each sampling point during the trapping period. Kidneys of captured animals were harvested and processed for Leptospira investigation. Additionally, environmental survey was conducted at each trapping point to obtain information about possible variables supporting small mammal assemblage. We used a generalized linear model to evaluate the effect of different socio-environmental variables on small mammals’ assemblage. Results: A total of 89 small mammals, specifically, Rattus norvegicus (n=39), Rattus rattus (n=27), Rattus exulans (n=10), Suncus murinus (n=11), and Tupaia glis (n=2) were captured from 1 385 trap nights. Fourteen individuals (15.7%) of the captured animals tested positive for Leptospira bacteria using PCR detection. Results of our generalized linear model showed only residences bordering vacant lots as the variable positively associated with small mammal occurrence in the three study sites. Conclusions: Small mammal community, especially the often neglected species, could harbour and potentially contribute towards pathogenic Leptospira maintenance in the study sites. To adequately control small mammals’ population and subsequent human zoonoses transmission, it is critical to advocate and promote appropriate infrastructure and suburban services, together with good hygiene practices that can reduce the animals’ access to food and harborage.

Redescription, molecular characterisation and Wolbachia endosymbionts of Mansonella (Tupainema) dunni (Mullin & Orihel, 1972) (Spirurida: Onchocercidae) from the common treeshrew Tupaia glis Diard & Duvaucel (Mammalia: Scandentia) in Peninsular Malaysia

The genus Mansonella Faust, 1929 includes 29 species, mainly parasites of platyrrhine monkeys in South America and anthropoid apes in Africa. In Malaysia, Mansonella (Tupainema) dunni (Mullin & Orihel, 1972) was described from the common treeshrew Tupaia glis Diard & Duvaucel (Scandentia). In a recent classification of the genus Mansonella, seven subgenera were proposed, with M. (Tup.) dunni as a monotypic species in the subgenus Tupainema. In this study, we collected new material of M. (Tup.) dunni from common treeshrews in Peninsular Malaysia and redescribed the morphological features of this species. We found that M. (Tup.) dunni differs from M. (Cutifilaria) perforata Uni et al., 2004 from sika deer Cervus nippon (Cetartiodactyla) in Japan, with regards to morphological features and predilection sites in their respective hosts. Based on multi-locus sequence analyses, we examined the molecular phylogeny of M. (Tup.) dunni and its Wolbachia genotype. Species of the genus Mansonella grouped monophyletically in clade ONC5 and M. (Tup.) dunni was placed in the most derived position within this genus. Mansonella (Tup.) dunni was closely related to M. (M.) ozzardi (Manson, 1897) from humans in Central and South America, and most distant from M. (C.) perforata. The calculated p-distances between the cox1 gene sequences for M. (Tup.) dunni and its congeners were 13.09% for M. (M.) ozzardi and 15.6–16.15% for M. (C.) perforata. The molecular phylogeny of Mansonella spp. thus corroborates their morphological differences. We determined that M. (Tup.) dunni harbours Wolbachia endosymbionts of the supergroup F genotype, in keeping with all other Mansonella species screened to date.

PREVALENCE OF PATHOGENIC Leptospira spp. IN SMALL MAMMAL HOSTS FROM DUNGUN, TERENGGANU

Leptospirosis is a zoonotic disease caused by Leptospira, which is transmitted through infected mammalian species, including small mammals. However, the prevalence of pathogenic Leptospira spp. in small mammals, particularly between different site categories in the eastern part of Peninsular Malaysia, is still underexplored. Therefore, in this study, we aimed to determine the species composition of small mammals and the prevalence of pathogenic Leptospira spp. between different site categories from Dungun, Terengganu. We selected five case sites (leptospirosis cases were recorded) and five control sites (no leptospirosis cases were recorded) in Dungun, Terengganu, based on previous reports by the Ministry of Health (MOH) Malaysia (2016-2020). For three consecutive nights, 100 cage traps were used for each trapping session. In addition, kidney samples from captured individuals were extracted for the Polymerase Chain Reaction (PCR) detection of pathogenic Leptospira spp. Overall, 89 individuals from five species were captured (6.43% trapping success), consisting of Rattus norvegicus (n = 39), Rattus rattus (n = 27), Suncus murinus (n = 11), Rattus exulans (n = 10) and Tupaia glis (n = 2). Out of 89 individuals captured, 14 tested positive with a 15.7% (n = 14/89) prevalence rate. R. norvegicus was the most dominant captured species and had the highest number of infected individuals with pathogenic Leptospira (20.5%, n = 8/39). The statistical analysis revealed that there is a significant difference in pathogenic Leptospira spp. between case and control sites (P < 0.05), with control sites recording higher positive individuals (78.6%, n = 11/14) compared to case sites (21.4%, n = 3/14). However, no significant differences were observed between species and sex (P > 0.05). The results show that the monitoring of leptospirosis cases should not only focus on case areas but also control areas in order to prevent the outbreak of this disease in the future.

Molecular Surveillance for Vector-Borne Bacteria in Rodents and Tree Shrews of Peninsular Malaysia Oil Palm Plantations

Many human clinical cases attributed to vector-borne pathogens are underreported in Malaysia, especially in rural localities where healthcare infrastructures are lacking. Here, 217 small mammals, consisting of rodents and tree shrews, were trapped in oil palm plantations in the Peninsular Malaysia states of Johor and Perak. Species identification was performed using morphological and DNA barcoding analyses, and 203 small mammals were included in the detection of selected vector-borne bacteria. The DNA extracted from the spleens was examined for Orientia tsutsugamushi, Borrelia spp., Bartonella spp. and Rickettsia spp. using established PCR assays. The small mammals collected in this study included Rattus tanezumi R3 mitotype (n = 113), Rattus argentiventer (n = 24), Rattus tiomanicus (n = 22), Rattus exulans (n = 17), Rattus tanezumi sensu stricto (n = 1) and Tupaia glis (n = 40). Orientia tsutsugamushi, Borrelia spp. and Bartonella phoceensis were detected in the small mammals with the respective detection rates of 12.3%, 5.9% and 4.9%. Rickettsia spp., however, was not detected. This study encountered the presence of both Lyme disease and relapsing fever-related borreliae in small mammals collected from the oil palm plantation study sites. All three microorganisms (Orientia tsutsugamushi, Borrelia spp. and Bartonella phoceensis) were detected in the R. tanezumi R3 mitotype, suggesting that the species is a competent host for multiple microorganisms. Further investigations are warranted to elucidate the relationships between the ectoparasites, the small mammals and the respective pathogens.

Viral Strategies for Targeting and Manipulating Opioidergic Neuronal Populations for Cell Specific Study and Therapeutic Intervention

With concurrent global epidemics of opioid use and chronic pain disorders, there is a critical need to identify, target, observe and manipulate specific cell populations in the peripheral and central nervous systems expressing the mu-opioid receptor (MOR). To gain long-term access to neural cells types and circuits involved in modulating pain, analgesia and addiction, we have developed a catalog of MOR specific promoter constructs (MORsp) for driving transgene expression in MOR+ cells compatible with use in AAV vectors. Working off the mouse Oprm1 promoter, we created a pAAV1-mMORsp-eYFP construct and confirmed its expression in cultured rat cortical neurons. To validate MOR+ cell-type selectivity in vivo, we performed intracranial injections into several structures implicated in pain-processing, opioid analgesia and drug reward in C57BL6/J mice, including: PFC, insula, amygdala, VTA, PAG and spinal cord. Robust expression of the reporter tag was observed in all regions, and in situ hybridization studies demonstrated eYFP transcript signal overlaps heavily with endogenous Oprm1 mRNA expression patterns. Comparable levels of reporter were also observed in the CeA and VTA of injected Sprague-Dawley rats and common tree shrews. Next, MORsp construct variants designed to drive expression of the chemogenetic receptor hM4Di and calcium activity indicator GCaMP6f were injected into mouse spinal cord and amygdala, respectively. Behavioral responses to noxious mechanical and heat stimuli were markedly decreased in hM4Di-expressing animals following DREADD agonist administration, and noxious heat stimuli produced robust GCaMP6f-mediated calcium transients that were morphine-sensitive. In addition to mouse promoter based constructs, we created a human Oprm1 promoter variant and confirmed its selective expression in OPRM1+ neurons in macaque PFC, insula, and amygdala. In total, our new MORsp toolkit provides researchers cell-type specific genetic access to monitor and functionally manipulate opioidergic neural circuits across a range of vertebrate species and translational screening models for pain and addiction. Grant support from Harnessing cortical neuromodulation to disrupt pain perception (1DP2GM140923-01) T32 Translational Addiction Research Fellowship Program (5T32DA028874-11).

First Record of the Tortoise Tick, Amblyomma geoemydae (Cantor, 1847) (Acari: Ixodidae) Parasitizing a Tree Shrew, Tupaia glis (Scandentia: Tupaiidae) in West Malaysia.

The tick genus Amblyomma Koch, 1844 (Acari: Ixodidae) has received little attention in Malaysia; therefore, its associated hosts and distribution records are poorly known. In this study, we collected six Amblyomma sp. individuals (two larvae and four adults) that infested a common treeshrew, Tupaia glis (Diard, 1820) (Scandentia: Tupaiidae) caught in a recreational area in Sungai Lembing, Pahang (West Malaysia). The adult female ticks were morphologically identified according to taxonomic keys prior to molecular identification using cytochrome oxidase subunit I (COI) and 16S rDNA genes. The ticks were genetically verified as Amblyomma geoemydae (Cantor, 1847) with 98%-99% similarity to the available GenBank sequences. Neighbor-joining (NJ) trees indicated that A. geoemydae was clearly distinguished from other Amblyomma ticks and this was supported with high bootstrap values. This paper is the first to report A. geoemydae ticks infesting T. glis and provides a new tick-host record from West Malaysia. This information is significant for further investigation, specifically on this tick species as potential vector of tick-borne disease (TBD) agents.

BAIT PREFERENCES BY DIFFERENT SMALL MAMMAL ASSEMBLAGES FOR EFFECTIVE CAGE-TRAPPING

The ecological study of small mammals often uses the cage-trapping method, installed with baits. Capture rates vary according to different baits used. We want to determine the bait preferences by different small mammal groups. The cage-trapping approach used common domestic bait types available, namely, aromatic banana, sweet potato with peanut butter, oil palm fruit, dried salted fish, jackfruit, and roasted coconut flesh. Sampling was conducted in three different habitat categories, namely urban, semi-urban, and recreational forests, located in Selangor, Malaysia, for one year. A total of 537 small mammals from 15 species were sampled, which was then grouped into seven groups (i.e., Rattus sp., Maxomys sp., Sundamys sp., Leopaldamys sabanus, Suncus murinus, squirrels, and Tupaia glis). Bait preferences were significantly different among the different small mammal groups, i.e., F (6,35) = 5.621, p = 0.000, with bananas shown to be most preferred bait, followed by oil palm fruits and sweet potatoes. Non-metric multidimensional scaling (nMDS) analysis revealed that the Rattus species encompassed the most diverse bait preference, while S. murinus and L. sabanus were the most selective. Muridae preferred sweet potatoes with peanut butter over bananas, while Sciuridae and Tupaiidae preferred bananas, and Soricidae preferred dried salted fish. This study elucidates the most effective bait selection for different small mammal assemblages, serving as a guide to increase capture rates when sampling targeted population of small mammals. Apart from that, it is helpful for effective rodent pest control.

Genetic diversity and expanded host range of astroviruses detected in small mammals in Singapore

Astroviruses are a genetically diverse group of viruses that infect a wide range of hosts, including small mammals. Small mammals were trapped at 19 sites across Singapore from November 2011 to May 2014. Pooled oropharyngeal and rectal swabs (n = 518) and large intestine tissue (n = 107) were screened using a PCR to detect the presence of Astrovirus RNA-dependent RNA polymerase (RdRp) gene. Astroviruses were detected in 93 of 625 (14.9%) of samples tested, with eight of 11 species of rats, shrews, and squirrels testing positive. This is the first detection of astroviruses in seven species (Callosciurus notatus, Mus castaneus, Rattus tanezumi, Rattus tiomanicus, Sundamys annandalei, Suncus murinus and Tupaia glis). Phylogenetic analysis of 10 RdRp gene sequences revealed that astroviruses from Singapore small mammals fall in three distinct clades, one that is specific to the common treeshrew (Tupaia glis), and two comprised of multiple species. One of these includes viruses from the cave nectar bat (Eonycteris spelaea), two rodent species, and a squirrel, suggesting that virus spillover from bats to small mammals may have occurred. Our results show an increased host range for astroviruses and highlight their potential for intra- and inter-species transmission.

Morphological characteristics of microfilariae in blood smears of the common treeshrew Tupaia glis (Mammalia: Scandentia) in Gemas, Negeri Sembilan, Malaysia.

Some filarial nematodes, such as Wuchereria bancrofti, Brugia malayi, and Brugia timori, cause lymphatic diseases in humans in the tropics, whereas other filarial parasites from wild animals cause zoonotic diseases in humans worldwide. To elucidate the prevalence and diversity of filarial parasites in Malaysia, we investigated the filarial parasites from wild animals in Gemas, Negeri Sembilan. To find adult filarial parasites, we dissected 26 animals, which included five frogs, one skink, one snake, two birds, six common treeshrews, and 11 rats. Then, we examined microfilariae in the blood smears and skin snips obtained from each animal. We found two types of microfilariae in the blood smears of common treeshrews: one was very similar to Malayfilaria sofiani and the other closely resembled Brugia tupaiae. These findings indicate an additional distribution of these filarial parasites in Gemas.

The tetramerization domain of the tree shrew p53 protein displays unique thermostability despite sharing high sequence identity with the human p53 protein

The p53 protein plays a number of roles in protecting organisms from different genotoxic stresses and this includes DNA damage induced by acetaldehyde, a metabolite of alcohol. Since the common tree shrew ingests high levels of alcohol as part of its normal diet, this suggests that its p53 protein may possess unique properties. Using a combination of biophysical and modeling studies, we demonstrate that the tetramerization domain of the tree shrew p53 protein is considerably more stable than the corresponding domain from humans despite sharing almost 90% sequence identity. Based on modeling and mutagenesis studies, we determine that a glutamine to methionine substitution at position 354 plays a key role in this difference. Given the link between stability of the p53 tetramerization domain and its transcriptional activity, the results suggest that this enhanced stability could lead to important consequences at p53-regulated genes in the tree shrew.

New records of rodent species in Bangladesh: taxonomic studies from rodent outbreak areas in the Chittagong hill tracts

Rodents are regarded as crop pests, significant reservoirs and vectors for many zoonotic diseases around the world. Basic taxonomic information of rodents present in a locality can help understand which species are responsible as crop pest in that habitat. The phenomenon of the 50-year cycle of gregarious bamboo flowering and rodent outbreaks in the Chittagong Hill Tracts (CHT) of Bangladesh, rodents trapping were carried out in four habitats from March, 2009 to December, 2011 in Ruma upazila of Bandarban hill district. Variety of traps were used to capture small mammals. The captured species were measured and identified using taxonomical dichotomous keys and DNA bar-coding performed in Australia. A total of 14 different small mammalian species were captured of which nine belonging to the Muridae family, and one species each of Spalacidae, Sciuridae, Tupaiidae and Soricidae families. The dominant small mammal species captured were Rattus rattus (54.06%) followed by Mus musculus (26.39%), Rattus nitidus (10.98%), Suncus murinus (5.45%), Mus terricolor (1.09%), Mus cookii nagarum (0.97%), Cannomys badius (0.16%), Leopoldamys edwardsi (0.12%), Berylmys bowersi (0.12%), Vernaya fulva (0.08%), Rattus andamanensis (0.08%), Tupaia glis (0.04%) and Callosciurus pygerythrus (0.04%). Rattus nitidus, Leopoldamys edwardsi, Vernaya fulva, Rattus andamanensis, Berylmys bowersi and Mus cookii nagarum are new records of rodent species in Bangladesh. Ten individuals of Mus spp. (0.40%) were not identified to species level, requiring further genetic analysis to determine their species. The implications of these discoveries are discussed in terms of agricultural pests.
 Bangladesh J. Zool. 46(2): 217-230, 2018

Rule reversal: Ecogeographical patterns of body size variation in the common treeshrew (Mammalia, Scandentia).

There are a number of ecogeographical “rules” that describe patterns of geographical variation among organisms. The island rule predicts that populations of larger mammals on islands evolve smaller mean body size than their mainland counterparts, whereas smaller‐bodied mammals evolve larger size. Bergmann's rule predicts that populations of a species in colder climates (generally at higher latitudes) have larger mean body sizes than conspecifics in warmer climates (at lower latitudes). These two rules are rarely tested together and neither has been rigorously tested in treeshrews, a clade of small‐bodied mammals in their own order (Scandentia) broadly distributed in mainland Southeast Asia and on islands throughout much of the Sunda Shelf. The common treeshrew, Tupaia glis, is an excellent candidate for study and was used to test these two rules simultaneously for the first time in treeshrews. This species is distributed on the Malay Peninsula and several offshore islands east, west, and south of the mainland. Using craniodental dimensions as a proxy for body size, we investigated how island size, distance from the mainland, and maximum sea depth between the mainland and the islands relate to body size of 13 insular T. glis populations while also controlling for latitude and correlation among variables. We found a strong negative effect of latitude on body size in the common treeshrew, indicating the inverse of Bergmann's rule. We did not detect any overall difference in body size between the island and mainland populations. However, there was an effect of island area and maximum sea depth on body size among island populations. Although there is a strong latitudinal effect on body size, neither Bergmann's rule nor the island rule applies to the common treeshrew. The results of our analyses demonstrate the necessity of assessing multiple variables simultaneously in studies of ecogeographical rules.

Detection and genetic characterization of diverse Bartonella genotypes in the small mammals of Singapore.

Bartonella species are arthropod-borne bacterial pathogens that infect numerous mammalian species. Small mammals play an important role as natural reservoirs of many Bartonella species, maintaining the greatest diversity of Bartonella described to date. Although Bartonella research has been conducted in Southeast Asia, no studies have been undertaken on small mammals in Singapore. Here, we report the detection and description of Bartonella in small mammals in Singapore during the period of November 2011 to May 2014. BartonellaDNA was detected in 20.8% (22/106) of small mammal spleens with a PCR amplifying the beta subunit of bacterial RNA polymerase (rpoB) gene. Commensal species Rattus norvegicus and Rattus tanezumi had the highest prevalence, 75% (3/4) and 34,5% (10/29), followed by Suncus murinus 30% (6/20), Tupaia glis 16,7% (1/6) and Mus castaneus 13.3% (2/15). Phylogenetic analysis of 18 rpoB gene sequences revealed five Bartonella genotypes circulating in the small mammals of Singapore. Bayesian tip-significance testing demonstrated strong structuring in the geographical signal, indicating that distribution of Bartonella species is correlated to the distribution of their hosts. Major deforestation and fragmentation in Singapore favour synanthropic species that traverse habitats and increase the possibility of spillover to incidental hosts.

Morphological and molecular characteristics of Malayfilaria sofiani Uni, Mat Udin & Takaoka n. g., n. sp. (Nematoda: Filarioidea) from the common treeshrew Tupaia glis Diard & Duvaucel (Mammalia: Scandentia) in Peninsular Malaysia

BackgroundThe filarial nematodes Wuchereria bancrofti (Cobbold, 1877), Brugia malayi (Brug, 1927) and B. timori Partono, Purnomo, Dennis, Atmosoedjono, Oemijati & Cross, 1977 cause lymphatic diseases in humans in the tropics, while B. pahangi (Buckley & Edeson, 1956) infects carnivores and causes zoonotic diseases in humans in Malaysia. Wuchereria bancrofti, W. kalimantani Palmieri, Pulnomo, Dennis & Marwoto, 1980 and six out of ten Brugia spp. have been described from Australia, Southeast Asia, Sri Lanka and India. However, the origin and evolution of the species in the Wuchereria-Brugia clade remain unclear. While investigating the diversity of filarial parasites in Malaysia, we discovered an undescribed species in the common treeshrew Tupaia glis Diard & Duvaucel (Mammalia: Scandentia).MethodsWe examined 81 common treeshrews from 14 areas in nine states and the Federal Territory of Peninsular Malaysia for filarial parasites. Once any filariae that were found had been isolated, we examined their morphological characteristics and determined the partial sequences of their mitochondrial cytochrome c oxidase subunit 1 (cox1) and 12S rRNA genes. Polymerase chain reaction (PCR) products of the internal transcribed spacer 1 (ITS1) region were then cloned into the pGEM-T vector, and the recombinant plasmids were used as templates for sequencing.ResultsMalayfilaria sofiani Uni, Mat Udin & Takaoka, n. g., n. sp. is described based on the morphological characteristics of adults and microfilariae found in common treeshrews from Jeram Pasu, Kelantan, Malaysia. The Kimura 2-parameter distance between the cox1 gene sequences of the new species and W. bancrofti was 11.8%. Based on the three gene sequences, the new species forms a monophyletic clade with W. bancrofti and Brugia spp. The adult parasites were found in tissues surrounding the lymph nodes of the neck of common treeshrews.ConclusionsThe newly described species appears most closely related to Wuchereria spp. and Brugia spp., but differs from these in several morphological characteristics. Molecular analyses based on the cox1 and 12S rRNA genes and the ITS1 region indicated that this species differs from both W. bancrofti and Brugia spp. at the genus level. We thus propose a new genus, Malayfilaria, along with the new species M. sofiani.

The wavelength composition and temporal modulation of ambient lighting strongly affect refractive development in young tree shrews

Shortly after birth, the eyes of most animals (including humans) are hyperopic because the short axial length places the retina in front of the focal plane. During postnatal development, an emmetropization mechanism uses cues related to refractive error to modulate the growth of the eye, moving the retina toward the focal plane. One possible cue may be longitudinal chromatic aberration (LCA), to signal if eyes are getting too long (long [red] wavelengths in better focus than short [blue]) or too short (short wavelengths in better focus). It could be difficult for the short-wavelength sensitive (SWS, “blue”) cones, which are scarce and widely spaced across the retina, to detect and signal defocus of short wavelengths. We hypothesized that the SWS cone retinal pathway could instead utilize temporal (flicker) information. We thus tested if exposure solely to long-wavelength light would cause developing eyes to slow their axial growth and remain refractively hyperopic, and if flickering short-wavelength light would cause eyes to accelerate their axial growth and become myopic. Four groups of infant northern tree shrews (Tupaia glis belangeri, dichromatic mammals closely related to primates) began 13 days of wavelength treatment starting at 11 days of visual experience (DVE). Ambient lighting was provided by an array of either long-wavelength (red, 626 ± 10 nm) or short-wavelength (blue, 464 ± 10 nm) light-emitting diodes placed atop the cage. The lights were either steady, or flickering in a pseudo-random step pattern. The approximate mean illuminance (in human lux) on the cage floor was red (steady, 527 lux; flickering, 329 lux), and blue (steady, 601 lux; flickering, 252 lux). Refractive state and ocular component dimensions were measured and compared with a group of age-matched normal animals (n = 15 for refraction (first and last days); 7 for ocular components) raised in broad spectrum white fluorescent colony lighting (100–300 lux).During the 13 day period, the refraction of the normal animals decreased from (mean ± SEM) 5.8 ± 0.7 diopters (D) to 1.5 ± 0.2 D as their vitreous chamber depth increased from 2.77 ± 0.01 mm to 2.80 ± 0.03 mm. Animals exposed to red light (both steady and flickering) remained hyperopic throughout the treatment period so that the eyes at the end of wavelength treatment were significantly hyperopic (7.0 ± 0.7 D, steady; 4.7 ± 0.8 D, flickering) compared with the normal animals (p < 0.01). The vitreous chamber of the steady red group (2.65 ± 0.03 mm) was significantly shorter than normal (p < 0.01). On average, steady blue light had little effect; the refractions paralleled the normal refractive decrease. In contrast, animals housed in flickering blue light increased the rate of refractive decrease so that the eyes became significantly myopic (−2.9 ± 1.3 D) compared with the normal eyes and had longer vitreous chambers (2.93 ± 0.04 mm). Upon return to colony lighting, refractions in all groups gradually returned toward emmetropia. These data are consistent both with the hypothesis that LCA can be an important visual cue for postnatal refractive development, and that short-wavelength temporal flicker provides an important cue for assessing and signaling defocus.

Skeletal variation and taxonomic boundaries among mainland and island populations of the common treeshrew (Mammalia: Scandentia: Tupaiidae)

Skeletal variation and taxonomic boundaries among mainland and island populations of the common treeshrew (Mammalia: Scandentia: Tupaiidae)

Ectoparasite of Tupaia glis (Scandentia: Tupaiidae) from Lingai agricultural area, Terengganu

ObjectiveTo investigate ectoparasite fauna on the common tree shrew [Tupaia glis (T. glis)] in Lingai agriculture area, Terengganu. MethodsThe sampling was conducted once a month with five consecutive days from November 2012 to February 2013. Five mammal cage traps (60 cm × 30 cm × 30 cm) and 30 rat cage traps (45 cm × 15 cm × 15 cm) baited with banana, salt fish or fleshy-grilled coconut were used. One line transect was built and each trap was set up along the line transect with 5 m intervals. Ectoparasite was collected by combing host's fur vigorously and kept in vials containing 70% ethanol. ResultsOut of 23 hosts examined, 20 individuals (87%) of T. glis in Lingai agricultural area were infested by three species of ticks and two species of mites. It was found that Laelaps echidninus showed higher mean intensity (5) as compared to the other ectoparasites. However, the prevalence was higher on Ixodes sp. (43.5%) though its mean intensity was among the lowest (1.9) from the rest. ConclusionsThis study provides useful information of ectoparasite fauna infesting T. glis in the agricultural area. It is important to have knowledge regarding what type of ectoparasite infests small animals in agricultural area, which in turn can assist responsible agencies to take precaution if epidemic outbreaks caused by tick-borne zoonotic diseases occur in the future.

Diversity and biomass of terrestrial small mammals at a Malaysian primary rainforest reserve (Segari Melintang Forest Reserve, Peninsular Malaysia)

Despite their importance for the rain forest ecosystem, still not much known about the community composition of small frugivorous mammals in West-Malaysian forests. Therefore, we conducted a mark and recapture study in four 100 m x 100 m sized plots in a lowland Dipterocarp forest of Peninsular Malaysia for 4000 trap nights. Plots hosted either Dipterocarp forest or alluvial fresh water swamp vegetation. We assumed that small mammal assemblages varied between these two vegetation types. In total 249 different individuals of 14 species (9 genera) were caught, comprising rodents and treeshrews. The most abundant species was the common tree shrew ( Tupaia gli s, 25.8 individuals ha -1 ), followed the plantain squirrel ( Callosciurus notatus , 10.25 individuals ha -1 ) and the grey tree rat ( Lenothrix canus , 10.0 individuals ha -1 ). These three species accounted for 77.8% of the total small mammals biomass per hectare. Sex-ratio of treeshrews and squirrel species was found at 1:1, whereas Muridae showed male-biased sex-ratios. Shannon-diversity indices (H) of all trapping plots ranged at mediocre level. Plot comparison (Bray-Curtis indices) showed that plots with similar vegetation types were not more similar in their small mammal community structure. Other factors, such as distance to the forest edge and joining oil palm plantations seemed to influence species abundances. Small mammals belong to the less studied species in local rain forests, thus studying their ecology is vital in order to act towards general conservational issues.

Preliminary Study of Skull Polymorphims of Tupaia glis in Peninsular Malaysia by using MorphoJ

A global geographic fragmentation has caused the diversity of animals and plants worldwide, mostly to the population of small mammals. In Malaysia, there are a lot of natural barriers that can separate the population of small mammals including common treeshrew, Tupaia glis. In this study, the polymorphism of ninety (90) Tupaia glis in Peninsular Malaysia is carried out by comparing the skulls of the species from different states by using MorphoJ analysis. This is carried out to know the landmark of the species and the shape changes.

Mapping bone cell distributions to assess ontogenetic origin of primate midfacial form.

Midfacial reduction in primates has been explained as a byproduct of other growth patterns, especially the convergent orbits. This is at once an evolutionary and developmental explanation for relatively short snouts in most modern primates. Here, we use histological sections of perinatal nonhuman primates (tamarin, tarsier, loris) to investigate how orbital morphology emerges during ontogeny in selected primates compared to another euarchontan (Tupaia glis). We annotated serial histological sections for location of osteoclasts or osteoblasts, and used these to create three-dimensional "modeling maps" showing perinatal growth patterns of the facial skeleton. In addition, in one specimen we transferred annotations from histological sections to CT slices, to create a rotatable 3D volume that shows orbital modeling. Our findings suggest that growth in the competing orbital and neurocranial functional matrices differs among species, influencing modeling patterns. Distinctions among species are observed in the frontal bone, at a shared interface between the endocranial fossa and the orbit. The medial orbital wall is extensively resorptive in primates, whereas the medial orbit is generally depositional in Tupaia. As hypothesized, the orbital soft tissues encroach on available interorbital space. However, eye size cannot, by itself, explain the extent of reduction of the olfactory recess. In Loris, the posterior portion of medial orbit differed from the other primates. It showed evidence of outward drift where the olfactory bulb increased in cross-sectional area. We suggest the olfactory bulbs are significant to orbit position in strepsirrhines, influencing an expanded interorbital breadth at early stages of development.