Systematics and biogeography of shrews (soricomorpha: soricidae) in peninsular Malaysia / Hasmahzaiti Omar
total of 122 samples were examined in this study were trapped by using pitfall traps, except for Suncus murinus species, which was caught with a rat trap. The 14 skull characters of seven species measured from the past and present studies were subjected to principal component analysis. Although C...
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| Format: | Thesis |
| Published: |
2012
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| Online Access: | http://studentsrepo.um.edu.my/4454/ http://studentsrepo.um.edu.my/4454/1/THESIS_full_version.pdf |
| _version_ | 1848772644484153344 |
|---|---|
| author | Omar, Hasmahzaiti |
| author_facet | Omar, Hasmahzaiti |
| author_sort | Omar, Hasmahzaiti |
| building | UM Research Repository |
| collection | Online Access |
| description | total of 122 samples were examined in this study were trapped by using pitfall traps,
except for Suncus murinus species, which was caught with a rat trap. The 14 skull
characters of seven species measured from the past and present studies were subjected
to principal component analysis. Although Crocidura negligens was never trapped in
this study, earlier studies indicated that this species was distinct from other Crocidura
species. Currently, Crocidura monticola are commonly found in Peninsular Malaysia
and widely distributed in Sundaland. Previous studies indicated that Crocidura
fuliginosa was dominant species in this region. Meanwhile, the smallest shrew Suncus
malayanus formerly known as Suncus etruscus proved distinct morphologically from C.
monticola. Finally, in this study I provide identification keys for shrew species,
morphological measurements and skull drawings that may help in identification of
Malay peninsula shrews for future studies.
Small crocidurinae shrews (weight < 8g) from Southeast Asia have been poorly
studied to date, mainly because of the difficulty to catch them and the concomitant
paucity of reference specimens available in museums. Hence their systematics is still
debated, and most small Crocidura shrews from Sundaland are assigned to the
monticola species complex. Morphometric analyses based on 14 skull measurements
showed that these shrews tend to be larger with increasing altitude, but showed
otherwise no consistent variation. When compared to museum specimens of the
monticola species complex sampled in the Sundaland (total: 77 specimens), the Malay
shrews tend also to be larger than those living on Kalimantan and Sumatra. All are,
however, morphologically distinct from the other species, C. maxi, found in eastern Java
and on the Lesser Sundas. Molecular analyses of a subset of these small shrews based
iv
on a mitochondrial (cytochrome b) and a nuclear gene (Apolipoprotein B) suggest that
samples from the central region of Peninsular Malaysia (Bukit Rengit and Ulu Gombak)
differ genetically from other Malaysian populations (by about 7% K2P distance at the
cyt b gene) and are more closely related to some samples from Sumatra and Borneo.
These differences did not correlate with the altitudinal variation evidenced from the
morphological analysis. Reference sequences from the terra typica of monticola and
maxi (both species were originally described from Java) are however needed to
determine if these unexpected genetic differences warrant additional taxonomic
subdivision within the Sundaland.
A portion of the mitochondrial cytochrome b gene was used to investigate the
phylogenetic relationships of Suncus pygmy shrews and to help clarify the taxonomic
status of the Malayan Pygmy Shrew (S. malayanus) and the Malagasy Pygmy Shrew
(S. madagascariensis). Phylogenetic reconstructions were performed using neighbourjoining
and Bayesian analysis methods and revealed that S. malayanus is related to, but
distinct from S. etruscus. The K2P-corrected genetic distance among the Malaysian
taxon and other pygmy shrews for the cytochrome b gene was between 6.1 and 8.5%,
supporting recognition that S. malayanus represents a distinct species from the
geographically widespread S. etruscus species complex. A close (1.5% K2P distance)
sister-group relationship was revealed between S. etruscus from Sri Lanka and S.
madagascariensis from Madagascar, which has been considered an island endemic, and
suggests that these animals are not specifically distinct. The Malagasy population of this
shrew most probably was translocated to the island by human intervention, with the
lineage originating from Southeast Asia or the Indian subcontinent. |
| first_indexed | 2025-11-14T13:29:47Z |
| format | Thesis |
| id | um-4454 |
| institution | University Malaya |
| institution_category | Local University |
| last_indexed | 2025-11-14T13:29:47Z |
| publishDate | 2012 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | um-44542014-10-09T01:25:54Z Systematics and biogeography of shrews (soricomorpha: soricidae) in peninsular Malaysia / Hasmahzaiti Omar Omar, Hasmahzaiti Q Science (General) total of 122 samples were examined in this study were trapped by using pitfall traps, except for Suncus murinus species, which was caught with a rat trap. The 14 skull characters of seven species measured from the past and present studies were subjected to principal component analysis. Although Crocidura negligens was never trapped in this study, earlier studies indicated that this species was distinct from other Crocidura species. Currently, Crocidura monticola are commonly found in Peninsular Malaysia and widely distributed in Sundaland. Previous studies indicated that Crocidura fuliginosa was dominant species in this region. Meanwhile, the smallest shrew Suncus malayanus formerly known as Suncus etruscus proved distinct morphologically from C. monticola. Finally, in this study I provide identification keys for shrew species, morphological measurements and skull drawings that may help in identification of Malay peninsula shrews for future studies. Small crocidurinae shrews (weight < 8g) from Southeast Asia have been poorly studied to date, mainly because of the difficulty to catch them and the concomitant paucity of reference specimens available in museums. Hence their systematics is still debated, and most small Crocidura shrews from Sundaland are assigned to the monticola species complex. Morphometric analyses based on 14 skull measurements showed that these shrews tend to be larger with increasing altitude, but showed otherwise no consistent variation. When compared to museum specimens of the monticola species complex sampled in the Sundaland (total: 77 specimens), the Malay shrews tend also to be larger than those living on Kalimantan and Sumatra. All are, however, morphologically distinct from the other species, C. maxi, found in eastern Java and on the Lesser Sundas. Molecular analyses of a subset of these small shrews based iv on a mitochondrial (cytochrome b) and a nuclear gene (Apolipoprotein B) suggest that samples from the central region of Peninsular Malaysia (Bukit Rengit and Ulu Gombak) differ genetically from other Malaysian populations (by about 7% K2P distance at the cyt b gene) and are more closely related to some samples from Sumatra and Borneo. These differences did not correlate with the altitudinal variation evidenced from the morphological analysis. Reference sequences from the terra typica of monticola and maxi (both species were originally described from Java) are however needed to determine if these unexpected genetic differences warrant additional taxonomic subdivision within the Sundaland. A portion of the mitochondrial cytochrome b gene was used to investigate the phylogenetic relationships of Suncus pygmy shrews and to help clarify the taxonomic status of the Malayan Pygmy Shrew (S. malayanus) and the Malagasy Pygmy Shrew (S. madagascariensis). Phylogenetic reconstructions were performed using neighbourjoining and Bayesian analysis methods and revealed that S. malayanus is related to, but distinct from S. etruscus. The K2P-corrected genetic distance among the Malaysian taxon and other pygmy shrews for the cytochrome b gene was between 6.1 and 8.5%, supporting recognition that S. malayanus represents a distinct species from the geographically widespread S. etruscus species complex. A close (1.5% K2P distance) sister-group relationship was revealed between S. etruscus from Sri Lanka and S. madagascariensis from Madagascar, which has been considered an island endemic, and suggests that these animals are not specifically distinct. The Malagasy population of this shrew most probably was translocated to the island by human intervention, with the lineage originating from Southeast Asia or the Indian subcontinent. 2012 Thesis NonPeerReviewed application/pdf http://studentsrepo.um.edu.my/4454/1/THESIS_full_version.pdf Omar, Hasmahzaiti (2012) Systematics and biogeography of shrews (soricomorpha: soricidae) in peninsular Malaysia / Hasmahzaiti Omar. PhD thesis, University Malaya. http://studentsrepo.um.edu.my/4454/ |
| spellingShingle | Q Science (General) Omar, Hasmahzaiti Systematics and biogeography of shrews (soricomorpha: soricidae) in peninsular Malaysia / Hasmahzaiti Omar |
| title | Systematics and biogeography of shrews (soricomorpha: soricidae) in peninsular Malaysia / Hasmahzaiti Omar |
| title_full | Systematics and biogeography of shrews (soricomorpha: soricidae) in peninsular Malaysia / Hasmahzaiti Omar |
| title_fullStr | Systematics and biogeography of shrews (soricomorpha: soricidae) in peninsular Malaysia / Hasmahzaiti Omar |
| title_full_unstemmed | Systematics and biogeography of shrews (soricomorpha: soricidae) in peninsular Malaysia / Hasmahzaiti Omar |
| title_short | Systematics and biogeography of shrews (soricomorpha: soricidae) in peninsular Malaysia / Hasmahzaiti Omar |
| title_sort | systematics and biogeography of shrews (soricomorpha: soricidae) in peninsular malaysia / hasmahzaiti omar |
| topic | Q Science (General) |
| url | http://studentsrepo.um.edu.my/4454/ http://studentsrepo.um.edu.my/4454/1/THESIS_full_version.pdf |