Miniopterus brachytragos
Encyclopedia
Miniopterus brachytragos is a bat
in the genus Miniopterus
that occurs in northern and western Madagascar
. Populations of this species have historically been included in Miniopterus manavi, but molecular data published in 2008 and 2009 indicate this supposed species in fact consists of five separate species, including the newly described M. brachytragos. Up to four species of this group may occur in the same place. M. brachytragos has been found in dry and wet forests from sea level to 320 m (1050 ft) altitude.
Miniopterus brachytragos is a small, brown Miniopterus; its forearm length is 35 to 38 mm (1.4 to 1.5 in). The hairs of the underparts have buff tips. The short tragus (a projection in the outer ear) is an important distinguishing feature. The uropatagium (tail membrane) is well-furred and the palate
is concave.
is much more species-rich than previously thought. In a 1995 contribution to Faune de Madagascar on Malagasy bats, Randolph Peterson and colleagues listed four species of Miniopterus on Madagascar and the nearby Comoros
, including the small Miniopterus manavi with a broad distribution on both Madagascar and the Comoros. In 2008 and 2009, however, Steven Goodman
and colleagues presented evidence that the former concept of M. manavi in fact encompassed five morphologically and molecularly distinct species of small Miniopterus. These included M. manavi itself in the Central Highlands
, M. griveaudi
and M. aelleni
in the Comoros and northern and western Madagascar, M. mahafaliensis
in southwestern Madagascar, and M. brachytragos in northern and western Madagascar. The five recognized species of M. manavi-like bats are not each others' closest relatives, but apparently acquired their similarities through convergent evolution
. At some places (for example, Namoroka
) four cryptic species of M. manavi-like bats, including M. brachytragos, may occur together.
Miniopterus brachytragos was described as a new species in the second 2009 paper by Goodman and colleagues. The specific name combines the Ancient Greek
brachys "short" and tragos "goat" and refers to the short tragus (a fleshy projection in the inner side of the outer ear), one of the main distinguishing features of the species; the name of this structure derives from the Greek tragos. Analysis of sequences of the mitochondrial
cytochrome b
gene suggested that M. brachytragos is most closely related to the clade
of M. manavi and another Malagasy species, M. petersoni
. There was some variation within the species—the most distinctive individual, from the island of Nosy Komba, differed by about 2.1% from other individuals of the same species in its cytochrome b sequence—but Goodman and colleagues regarded their samples as insufficient for clear conclusions about phylogeographic
structure within the species.
In 28 to 30 specimens measured by Goodman and colleagues, total length was 83 to 92 mm (3.3 to 3.6 in), averaging 87.4 mm (3.4 in); tail length was 38 to 43 mm (1.5 to 1.7 in), averaging 40.2 mm (1.6 in); hindfoot length was 5 to 6 mm (about 0.2 in), averaging 5.8 mm (0.2 in); tragus length was 3 to 4 mm (0.1 to 0.2 in), averaging 3.9 mm (0.2 in); ear length was 9 to 11 mm (about 0.4 in), averaging 10.0 mm (0.4 in); forearm length was 35 to 38 mm (1.4 to 1.5 in), averaging 36.6 mm (1.4 in); and body mass was 2.9 to 6.3 g (0.1 to 0.22 oz), averaging 4.3 g (0.15 oz). There is no evidence for substantial size differences between males and females
.
In the skull, the rostrum (front part) is short relative to other small Malagasy Miniopterus and line-shaped. The central groove in the nasal depression is relatively broad and deep. The frontal bone
s are slightly rounded and bear an indistinct sagittal crest
. Further back on the braincase, the lambdoid crest is also poorly developed. The middle part of the palate
is concave, not flat as in M. aelleni and M. manavi. At the palate's back margin is a short, blunt posterior palatal spine. There are often foramina
(openings) in the palate near the last molar
. Miniopterus brachytragos has 36 teeth in the dental formula (three incisor
s, one canine, three premolar
s, and two molar
s in both upper toothrows and two incisors, one canine, two premolars, and three molars in the lower toothrows). As is characteristic of Miniopterus, the first upper premolar (P1) is smaller and more simplified than the second (P2).
different sites. In the Namoroka region, it has been recorded at 100 to 200 m (300 to 700 ft) altitude in dry forest and gallery forest
. Another specimen was caught in forest in a karst
region in Bemaraha. Near Daraina
in the northeast, the species occurs in eastern humid forest
mixed with dry forest at 320 m (1050 ft). At another northeastern site, on the Masoala Peninsula, it was found in lowland gallery forest near sea level. On Nosy Komba, its habitat consists of dry forest mixed with introduced Mangifera indica
(mango tree). Little is known of the ecology of M. brachytragos, but species of Miniopterus generally feed on insects, breed seasonally, and roost in large colonies in caves.
Bat
Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...
in the genus Miniopterus
Miniopterus
Miniopterus is a genus of bats and the only genus of the family Miniopteridae. The genus was previously placed in its own subfamily, Miniopterinae, of the vesper bat family, but is now classified in its own family....
that occurs in northern and western Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
. Populations of this species have historically been included in Miniopterus manavi, but molecular data published in 2008 and 2009 indicate this supposed species in fact consists of five separate species, including the newly described M. brachytragos. Up to four species of this group may occur in the same place. M. brachytragos has been found in dry and wet forests from sea level to 320 m (1050 ft) altitude.
Miniopterus brachytragos is a small, brown Miniopterus; its forearm length is 35 to 38 mm (1.4 to 1.5 in). The hairs of the underparts have buff tips. The short tragus (a projection in the outer ear) is an important distinguishing feature. The uropatagium (tail membrane) is well-furred and the palate
Palate
The palate is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but, in most other tetrapods, the oral and nasal cavities are not truly separate. The palate is divided into two parts, the anterior...
is concave.
Taxonomy
During the 2000s, molecular studies have revealed that the widely distributed African, Eurasian, and Australian genus MiniopterusMiniopterus
Miniopterus is a genus of bats and the only genus of the family Miniopteridae. The genus was previously placed in its own subfamily, Miniopterinae, of the vesper bat family, but is now classified in its own family....
is much more species-rich than previously thought. In a 1995 contribution to Faune de Madagascar on Malagasy bats, Randolph Peterson and colleagues listed four species of Miniopterus on Madagascar and the nearby Comoros
Comoros
The Comoros , officially the Union of the Comoros is an archipelago island nation in the Indian Ocean, located off the eastern coast of Africa, on the northern end of the Mozambique Channel, between northeastern Mozambique and northwestern Madagascar...
, including the small Miniopterus manavi with a broad distribution on both Madagascar and the Comoros. In 2008 and 2009, however, Steven Goodman
Steven Goodman
Steven Goodman is an American Conservation Biologist, and field biologist on staff in the Department of Zoology at the Field Museum of Natural History....
and colleagues presented evidence that the former concept of M. manavi in fact encompassed five morphologically and molecularly distinct species of small Miniopterus. These included M. manavi itself in the Central Highlands
Central Highlands (Madagascar)
The Central Highlands, Central High Plateau, or Hauts-Plateaux are a mountainous biogeographical region in central Madagascar. They include the contiguous part of the island's interior above 800 m altitude...
, M. griveaudi
Miniopterus griveaudi
Miniopterus griveaudi is a bat in the genus Miniopterus found on Grande Comore and Anjouan in the Comoros and in northern and western Madagascar. First described in 1959 from Grande Comore as a subspecies of the mainland African M. minor, it was later placed with the Malagasy M. manavi...
and M. aelleni
Miniopterus aelleni
Miniopterus aelleni is a bat in the genus Miniopterus that occurs on Anjouan in the Comoros and in northern and western Madagascar. It is a small, brown bat; its forearm length is 35 to 41 mm . The long tragus has a broad base and a blunt to rounded tip. The uropatagium is sparsely haired...
in the Comoros and northern and western Madagascar, M. mahafaliensis
Miniopterus mahafaliensis
Miniopterus mahafaliensis is a bat in the genus Miniopterus that occurs in southwestern Madagascar. Populations of this species have historically been included in Miniopterus manavi, but molecular data published in 2008 and 2009 indicate that this supposed species in fact consists of five separate...
in southwestern Madagascar, and M. brachytragos in northern and western Madagascar. The five recognized species of M. manavi-like bats are not each others' closest relatives, but apparently acquired their similarities through convergent evolution
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
. At some places (for example, Namoroka
Tsingy de Namoroka Strict Nature Reserve
Tsingy de Namoroka Strict Nature Reserve, also known as Namoroka National Park, is a strict nature reserve located in the northwestern part of Madagascar in the Mahajanga Province, specifically, the Soalala District.- Climate and geography :...
) four cryptic species of M. manavi-like bats, including M. brachytragos, may occur together.
Miniopterus brachytragos was described as a new species in the second 2009 paper by Goodman and colleagues. The specific name combines the Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
brachys "short" and tragos "goat" and refers to the short tragus (a fleshy projection in the inner side of the outer ear), one of the main distinguishing features of the species; the name of this structure derives from the Greek tragos. Analysis of sequences of the mitochondrial
Mitochondrial DNA
Mitochondrial DNA is the DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, adenosine triphosphate...
cytochrome b
Cytochrome b
Cytochrome b/b6 is the main subunit of transmembrane cytochrome bc1 and b6f complexes. In addition, it commonly refers to a region of mtDNA used for population genetics and phylogenetics.- Function :...
gene suggested that M. brachytragos is most closely related to the clade
Clade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
of M. manavi and another Malagasy species, M. petersoni
Miniopterus petersoni
Miniopterus petersoni is a bat in the genus Miniopterus which occurs in southeast Madagascar. It was described by Steven M. Goodman et al. in 2008. While M. petersoni is similar to M. sororculus, the two species are not closely related to each other, and possess a number of differing external and...
. There was some variation within the species—the most distinctive individual, from the island of Nosy Komba, differed by about 2.1% from other individuals of the same species in its cytochrome b sequence—but Goodman and colleagues regarded their samples as insufficient for clear conclusions about phylogeographic
Phylogeography
Phylogeography is the study of the historical processes that may be responsible for the contemporary geographic distributions of individuals. This is accomplished by considering the geographic distribution of individuals in light of the patterns associated with a gene genealogy.This term was...
structure within the species.
Description
Miniopterus brachytragos is a small, short-tailed Miniopterus with short and relatively thin fur. The fur of the upperparts is dark brown and the hairs on the underparts have buff tips. Miniopterus mahafaliensis is similar in color, but other small Malagasy Miniopterus are darker. The ears are haired above, but virtually naked below and end in a rounded tip. The tragus (a projection on the inner side of the outer ear) is short and has a broad base, sometimes with a crest at the side. It ends in a pointed to slightly rounded tip, which is covered with hairs that are not readily visible to the unaided eye. The short tragus easily distinguishes M. brachytragos from other Malagasy Miniopterus. The wing membrane is also brown, but the uropatagium (tail membrane) is lighter. The wing membrane and uropatagium are attached to the upper leg at the same level, above the ankle. The uropatagium is relatively densely covered with hairs, particularly on the upper side. M. manavi and M. mahafaliensis also have a densely haired uropatagium, but in M. aelleni and M. griveaudi it is only sparsely haired or even mostly naked.In 28 to 30 specimens measured by Goodman and colleagues, total length was 83 to 92 mm (3.3 to 3.6 in), averaging 87.4 mm (3.4 in); tail length was 38 to 43 mm (1.5 to 1.7 in), averaging 40.2 mm (1.6 in); hindfoot length was 5 to 6 mm (about 0.2 in), averaging 5.8 mm (0.2 in); tragus length was 3 to 4 mm (0.1 to 0.2 in), averaging 3.9 mm (0.2 in); ear length was 9 to 11 mm (about 0.4 in), averaging 10.0 mm (0.4 in); forearm length was 35 to 38 mm (1.4 to 1.5 in), averaging 36.6 mm (1.4 in); and body mass was 2.9 to 6.3 g (0.1 to 0.22 oz), averaging 4.3 g (0.15 oz). There is no evidence for substantial size differences between males and females
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
.
In the skull, the rostrum (front part) is short relative to other small Malagasy Miniopterus and line-shaped. The central groove in the nasal depression is relatively broad and deep. The frontal bone
Frontal bone
The frontal bone is a bone in the human skull that resembles a cockleshell in form, and consists of two portions:* a vertical portion, the squama frontalis, corresponding with the region of the forehead....
s are slightly rounded and bear an indistinct sagittal crest
Sagittal crest
A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull of many mammalian and reptilian skulls, among others....
. Further back on the braincase, the lambdoid crest is also poorly developed. The middle part of the palate
Palate
The palate is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but, in most other tetrapods, the oral and nasal cavities are not truly separate. The palate is divided into two parts, the anterior...
is concave, not flat as in M. aelleni and M. manavi. At the palate's back margin is a short, blunt posterior palatal spine. There are often foramina
Foramen
In anatomy, a foramen is any opening. Foramina inside the body of humans and other animals typically allow muscles, nerves, arteries, veins, or other structures to connect one part of the body with another.-Skull:...
(openings) in the palate near the last molar
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
. Miniopterus brachytragos has 36 teeth in the dental formula (three incisor
Incisor
Incisors are the first kind of tooth in heterodont mammals. They are located in the premaxilla above and mandible below.-Function:...
s, one canine, three premolar
Premolar
The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered as a 'transitional tooth' during chewing, or...
s, and two molar
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
s in both upper toothrows and two incisors, one canine, two premolars, and three molars in the lower toothrows). As is characteristic of Miniopterus, the first upper premolar (P1) is smaller and more simplified than the second (P2).
Distribution and ecology
Miniopterus brachytragos is known from several ecologicallyEcology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
different sites. In the Namoroka region, it has been recorded at 100 to 200 m (300 to 700 ft) altitude in dry forest and gallery forest
Gallery forest
Gallery forests are evergreen forests that form as corridors along rivers or wetlands and project into landscapes that are otherwise only sparsely treed such as savannas, grasslands or deserts....
. Another specimen was caught in forest in a karst
Karst topography
Karst topography is a geologic formation shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock such as limestone or dolomite, but has also been documented for weathering resistant rocks like quartzite given the right conditions.Due to subterranean drainage, there...
region in Bemaraha. Near Daraina
Daraina
Daraina is a town and commune in northern Madagascar. It belongs to the district of Vohemar, which is a part of Sava Region. The population of the commune was estimated to be approximately 10,000 in 2001 commune census....
in the northeast, the species occurs in eastern humid forest
Madagascar lowland forests
The Madagascar lowland forests are a tropical moist broadleaf forest ecoregion, found on the eastern coast of the island of Madagascar.-Setting:...
mixed with dry forest at 320 m (1050 ft). At another northeastern site, on the Masoala Peninsula, it was found in lowland gallery forest near sea level. On Nosy Komba, its habitat consists of dry forest mixed with introduced Mangifera indica
Mangifera indica
Mangifera indica is a species of mango in the Anacardiaceae family. It is found in the wild in India and cultivated varieties have been introduced to other warm regions of the world...
(mango tree). Little is known of the ecology of M. brachytragos, but species of Miniopterus generally feed on insects, breed seasonally, and roost in large colonies in caves.
Literature cited
- Goodman, S.M., Maminirina, C.P., Weyeneth, N., Bradman, H.M., Christidis, L., Ruedi, M. and Appleton, B. 2009a. The use of molecular and morphological characters to resolve the taxonomic identity of cryptic species: the case of Miniopterus manavi (Chiroptera: Miniopteridae) (subscription required). Zoologica Scripta 38:339–363.
- Goodman, S.M., Maminirina, C.P., Bradman, H.M., Christidis, L. and Appleton, B. 2009b. The use of molecular phylogenetic and morphological tools to identify cryptic and paraphyletic species: Examples from the diminutive long-fingered bats (Chiroptera: Miniopteridae: Miniopterus) on Madagascar. American Museum Novitates 3669:1–34.
- Nowak, R.M. 1994. Walker's Bats of the World. Baltimore: The Johns Hopkins University Press, 287 pp. ISBN 9780801849862
- Weyeneth, N., Goodman, S.M., Stanley, W.T. and Ruedi, M. 2008. The biogeography of Miniopterus bats (Chiroptera: Miniopteridae) from the Comoro Archipelago inferred from mitochondrial DNA (subscription required). Molecular Ecology 17:5205–5219.