Delicate Kleintenrek

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Delicate Kleintenrek
Systematics
without rank: Afroinsectiphilia
Order : Tenrecus (Afrosoricida)
Family : Tenreks (Tenrecidae)
Subfamily : Travel treks (Oryzorictinae)
Genre : Kleintenreks ( Microgale )
Type : Delicate Kleintenrek
Scientific name
Microgale gracilis
( Major , 1896)

The Gracious Kleintenrek ( Microgale gracilis ), also known as Gracile Kleintanrek , is a species of mammal from the genus Kleintenreks within the Tenreks family . He inhabits a relatively large area in the eastern part of Madagascar , which extends from north to south and mainly occupies the middle and higher mountain areas. There the animals prefer tropical rainforests . In general, they are rarely seen. They are medium-sized members of the Kleintenreks who, like their relatives, have a spindle-shaped body, strong limbs and a long, narrow head that tapers at the front. Special features are the bare nasal mirror , the particularly lightly built skull and the wide forefeet. The latter suggest that the graceful Kleintenrek digs underground burrows, otherwise hardly any information is available about the way of life. The species was described in 1896, the population is currently not threatened.

features

Habitus

The graceful Kleintenrek belongs to the medium-sized representatives of the Kleintenreks and is similar in appearance and size to the naked-nosed Kleintenrek ( Microgale gymnorhyncha ). Two examined individuals from the Andringitra Mountains in southeastern Madagascar had a total length of 18.0 and 18.2 cm, the head-trunk length was 10.5 and 9.4 cm and the tail length 7.5 and 8.4 cm. In comparison, six individuals from the Anosyenne Mountains , also located in southeastern Madagascar, had a body length of 8.8 to 9.6 cm and a tail length of 8.3 to 8.8 cm. The body weight varied from 21.5 to 24 g. From the Marojejy massif in north-eastern Madagascar, an individual was examined who was 8.5 cm long from head to torso and 9.3 cm long at the tail; the body weight was 19.5 g. Overall, the animals resemble a shrew in appearance like the other Kleintenreks . The body is spindle-shaped, the limbs are short and strong and the long, narrow head ends with a pointed tip. The tail reaches about the length of the rest of the body or becomes slightly shorter. The back fur has a dark brownish color with yellowish brown speckles, on the underside a dark gray predominates with yellowish brown washings. The tail is two-colored, on top it is dark brown, underneath it is light brown. The elongated snout, which forms a trunk-like nose, whose nasal surface is hairless, as in the bare-nosed small tenrek, is striking . The nasal mirror extends back about 4 to 5 mm and is therefore not quite as extensive as in the naked-nosed small tenrek. The surface is covered with a net-like corrugated pattern, the grooves in the rear area are incomplete. The head is equipped with small ears and small eyes, the former have a length of 15 to 18 mm and, when folded forward, touch the rear edge of the eyes. The ears are partly covered by fur. There are five toes each on the front and rear paws. The front feet in particular are very wide, the claws are longer than those of the rear feet. The rear foot has a length of 18 to 20 mm. Females have one pair of teats in the chest and two pairs in the groin.

Skull and dentition features

The skull of the graceful Kleintenreks is very long and light. The greatest length varies from 27.5 to 29.6 mm, the greatest width in the area of ​​the brain skull measures 9.2 to 11.1 mm. The rostrum is elongated, slender and low, the maximum width here at the level of the anterior premolar is 2.7 mm. As a result, the skull appears to be even lighter than that of the naked-nosed Kleintenrek. The nasal bone extends far back into the interocular region, at the front it is in contact with the median jawbone at the level of the anterior premolar . The rear of the skull is rounded, moderately widened and long. The parietal bone appears rather small compared to the elongated frontal bone , the occiput is built low. The lower jaw has an elongated shape and tapers anteriorly, the mental foramen lies below the anterior or between the first two premolars. The tooth formula is that the dentition is made up of 40 teeth. It is built very gracefully, the upper incisors and canines are very slender, comparatively large and similar in shape. On the lower canine tooth, the additional anterior cusp on the tooth crown, which occurs in the bare-nosed small tenrek, is missing. Between all upper front teeth and the first two premolars (P2 and P3) there are individual diastemas , which are extremely wide, especially between the premolar teeth, even wider than in the bare-nosed small tenrek. A tooth enamel bulge (cingulum) is sometimes formed on the tongue side on the upper first premolar. The molars same with their zalambdodonten Kauflächenmuster consisting of three Haupthöckerchen largely those of other microgale. As with these, the posterior upper molar is reduced in size. The length of the upper row of teeth varies between 9.9 and 14.9 mm.

distribution

Distribution area of ​​the graceful Kleintenreks

The graceful Kleintenrek is an endemic inhabitant of the island of Madagascar . Its occurrence is limited to a more or less wide strip in the eastern part of the island. Significant deposits are located in north-eastern Madagascar on the Marojejy and Anjanaharibe massifs in the Antsiranana province . Further south in the central highlands, the forest area of ​​Nosiarivo on the Ankaratra massif and the forest area of ​​Tsinjoarivo in the province of Antananarivo should be mentioned, while in south-eastern Madagascar the species from the forest area of ​​Ranomafana and the Andringitra mountains in the province of Fianarantsoa as well as from the Anosyenne Mountains in the province of Toliara . Moist mountain forests at altitudes of around 1200 to 2000 m serve as habitat. Little information is available about the frequency of the animals and they may be difficult to observe. In some areas, such as the Andringitra Mountains, the graceful Kleintenrek occurs in direct sympathy with the naked-nosed Kleintenrek ( Microgale gymnorhyncha ).

Way of life

There is only sporadic information about the way of life of the graceful little tenrec. All animals have so far been caught on the ground or in shallow undergrowth. Furthermore, the physique, such as the widened forefeet, the small ears, some of which are hidden by the fur, and the equally small eyes, suggest a partially subterranean way of life. According to isotope studies on animals from the forest area of ​​Tsinjoarivo, they mainly feed on insects . Young animals have a less speckled fur than old animals. External parasites have been detected with fleas of the genus Paractenopsyllus .

Systematics

Internal systematics of the Kleintenreks according to Everson et al. 2016
 Microgale  



 Microgale pusilla


   

 Microgale majori


   

 Microgale principula


   

 Microgale jenkinsae


   

 Microgale longicaudata






   

 Microgale mergulus


   

 Microgale parvula




   



 Microgale brevicaudata


   

 Microgale grandidieri



   

 Microgale drouhardi


   

 Microgale monticola


   

 Microgale taiva





   



 Microgale gracilis


   

 Microgale thomasi


   

 Microgale cowani


   

 Microgale jobihely





   

 Microgale dryas


   

 Microgale gymnorhyncha




   

 Microgale soricoides


   

 Microgale fotsifotsy


   

 Microgale nasoloi







Template: Klade / Maintenance / Style

The Grazile Kleintenrek is a kind from the genus of microgale ( Microgale ) within the family of tenrecs (Tenrecidae). The Kleintenreks form together with the rice burrowers ( Oryzorictes ) and the representatives of the genus Nesogale the subfamily of the Reistenreks (Oryzorictinae). They are also very varied and with more than 20 species represent the numerically strongest member of the Tenreks. Some morphological features suggest that the Little Tenreks occupy a rather original position within the family. According to molecular genetic studies, they formed in the Lower Miocene around 16.8 million years ago and diversified to a large extent in the period that followed. Today's representatives are adapted to different ways of life, some species that dig underground, live above ground, or tree-climb and inhabit water. The much larger part of the Kleintenreks lives in the damp forests of eastern Madagascar, a few forms have also opened up the drier landscapes of the western part of the island. Within the genus, different kinship groups can be distinguished both morphologically and genetically. In its external appearance, the graceful Kleintenrek is similar to the bare- nosed Kleintenrek ( Microgale gymnorhyncha ), which was only introduced in 1996, but from a genetic point of view it belongs to a group consisting of the Thomas Kleintenrek ( Microgale thomasi ), the Cowan-Kleintenrek ( Microgale cowani ) and the Dark Kleintenrek ( Microgale jobihely ) close.

The first scientific description of the graceful Kleintenreks goes back to Charles Immanuel Forsyth Major from 1896. He used the name Oryzoryctes gracilis ( incorrectly spelling the name Oryzorictes for the rice digger ). Major were two individuals available. The holotype , a 9.3 cm long individual with a 8.1 cm long tail, comes from the forest area of ​​Ambohimitombo, about 43 km southeast of Ambositra in the province of Fianarantsoa , the region represents the type locality. Major mentioned a second in the first description Animal from an area east of Antananarivo that was only available as a skeleton. The specific epithet gracilis refers to the very lightly built skull. Overall, Major saw similarities to the Kleintenreks, but the characteristically graceful skull prevented him from referring his new species to this genus. In principle he favored the establishment of a new genus, but instead placed the graceful Kleintenrek provisionally among the rice diggers. It was not until more than twenty years later created Oldfield Thomas with Leptogale a new genus for the delicate Kleintenrek which he based the fine head construction and wide diastema between the premolars defined. In general, the genus Leptogale is not recognized and is considered synonymous with Microgale . However, in the meantime, in 1972, Henri Heim de Balsac classified them as a subgenus of the Kleintenreks.

Subspecies of the graceful little tenrec are not known. From its first description until well into the second half of the 20th century, the species was only documented with the type material. Exceptions are two individuals who had already been observed in the Andringitra Mountains in the 1970s. An animal from Fanovana in the central highlands in the Toamasina province later turned out to be a representative of the bare-nosed small tenrec. Only with the extensive expeditions of the 1990s, which focused on research into the biological diversity of Madagascar, was it not only possible to gradually discover more specimens, but also to define the actual range of the species more precisely.

Threat and protection

Like most of the other members of the genus that occur in eastern Madagascar, the graceful Kleintenrek has a relatively large distribution area; the population is therefore assumed to be correspondingly large. The animals can also adapt to changed habitats. Larger threats are not known due to the distribution in higher mountain areas. Although the population is decreasing, Microgale gracilis is listed by the IUCN as “not endangered” ( least concern ). The animals are present in several protected areas, including the Marojejy National Park , the Ranomafana National Park , the Andringitra National Park and the Andohahela National Park . For better protection of the species, studies of the exact distribution and frequency are necessary.

literature

  • Paulina D. Jenkins, Steven M. Goodman and Christopher J. Raxworthy: The Shrew Tenrecs (Microgale) (Insectivora: Tenrecidae) of the Réserve Naturelle Intégrale d'Andringitra, Madagascar. Fieldiana Zoology 85, 1996, pp. 191-217
  • Paulina D. Jenkins: Tenrecidae (Tenrecs and Shrew tenrecs). In: Don E. Wilson and Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 8: Insectivores, Sloths and Colugos. Lynx Edicions, Barcelona 2018, pp. 134-172 (p. 170) ISBN 978-84-16728-08-4
  • Charles Immanuel Forsyth Major: Diagnoses of new mammals from Madagascar. The Annals and magazine of natural history 18, 1896, pp. 318–321 ( [4] )

Individual evidence

  1. ↑ a b c d e f Paulina D. Jenkins, Steven M. Goodman and Christopher J. Raxworthy: The Shrew Tenrecs (Microgale) (Insectivora: Tenrecidae) of the Réserve Naturelle Intégrale d'Andringitra, Madagascar. Fieldiana Zoology 85, 1996, pp. 191-217
  2. ↑ a b c d e Steven M. Goodman, Paulina D. Jenkins and Mark Pidgeon: Lipotyphla (Tenrecidae and Soricidae) of the Réserve Naturelle Intégrale d'Andohahela, Madagascar. Fieldiana Zoology 94, 1999, pp. 187-216
  3. ↑ a b c d e f Steven M. Goodman and Paulina D. Jenkins: Tenrecs (Lipotyphla; Tenrecidae) of the Parc National de Marojejy, Madagascar. Fieldiana Zoology 97, 2000, pp. 201-229
  4. ↑ a b c Paulina D. Jenkins: Tenrecidae (Tenrecs and Shrew tenrecs). In: Don E. Wilson and Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 8: Insectivores, Sloths and Colugos. Lynx Edicions, Barcelona 2018, pp. 134-172 (p. 170) ISBN 978-84-16728-08-4
  5. ↑ Voahangy Soarimalala and Steven M. Goodman: Diversité biologique the micromammifères non volants (Lipotyphla et Rodentia) dans le complexe Marojejy Anjanaharibe-sud. In: Steven M. Goodman and Lucienne Wilmé (eds.): Nouveaux résultats faisant référence à l'altitude dans la région des massifs montagneux de Marojejy et d'Anjanaharibe-sud. Recherche pour le développement, Série Sciences biologiques, Center d'Information et de Documentation Scientifique et Technique 19, 2003, pp. 231-276
  6. ↑ Steven M. Goodman, Daniel Rakotondravony, George Schatz and Lucienne Wilmé: Species richness of forest-dwelling birds, rodents and insectivores in a planted forest of native trees: A test case from the Ankaratra, Madagascar. Ecotropica 2, 1996, pp. 109-120
  7. ↑ Steven M. Goodman, Daniel Rakotondravony, Marie Jeanne Raherilalao, Domoina Rakotomalala, Achille P. Raselimanana, Voahangy Soarimalala, Jean-Marc Duplantier, Jean-Bernard Duchemin and J. Rafanomezantsoa: Inventaire biologique de la Foret de Tsinjoarivo, Ambatolampy. Akon'ny Ala 27, 2000, pp. 18-27
  8. ↑ Landryh Tojomanana Ramanana: Petits mammifères (Afrosoricida et Rodentia) nouvellement recensés dans le Parc National d'Andohahela (parcelle 1), Madagascar. Malagasy Nature 4, 2010, pp. 66-72
  9. ^ A b Steven M. Goodman, Christopher J. Raxworthy and Paulina D. Jenkins: Insectivore ecology in the Réserve Naturelle Intégrale d'Andringitra, Madagascar. Fieldiana Zoology 85, 1996, pp. 218-231
  10. ↑ a b c P. J. Stephenson, Voahangy Soarimalala and Steven M. Goodman: Microgale gracilis. The IUCN Red List of Threatened Species 2016. e.T13343A97191617 ( [1] ); last accessed on October 16, 2016
  11. ↑ Melanie Dammhahn, Voahangy Soarimalala and Steven M. Goodman: Trophic Niche Differentiation and Microhabitat Utilization in a Species-rich Montane Forest Small Mammal Community of Eastern Madagascar. Biotropica 45 (1), 2013, pp. 111-118
  12. ↑ Michael W. Hastriter and Carl W. Dick: A description of Paractenopsyllus madagascarensis sp. n. and the female of Paractenopsyllus raxworthyi Duchemin & Ratovonjato, 2004 (Siphonaptera, Leptopsyllidae) from Madagascar with a key to the species of Paractenopsyllus. ZooKeys 13, 2009, pp. 43-55
  13. ↑ a b c Kathryn M. Everson, Voahangy Soarimalala, Steven M. Goodman and Link E. Olson: Multiple loci and complete taxonomic sampling resolve the phylogeny and biogeographic history of tenrecs (Mammalia: Tenrecidae) and reveal higher speciation rates in Madagascar's humid forests . Systematic Biology 65 (5), 2016, pp. 890-909 doi: 10.1093 / sysbio / syw034
  14. ^ JF Eisenberg and Edwin Gould: The Tenrecs: A Study in Mammalian Behavior and Evolution. Smithsonian Institution Press, 1970, pp. 1-138
  15. ↑ a b c d R. DE MacPhee: The Shrew Tenrecs of Madagascar: Systematic Revision and Holocene Distribution of Microgale (Tenrecidae, Insectivora). American Museum Novitates 2889, 1987, pp. 1-45
  16. ^ Charles Immanuel Forsyth Major: Diagnoses of new mammals from Madagascar. The Annals and magazine of natural history 18, 1896, pp. 318-321
  17. ↑ Oldfield Thomas: On the arrangement of the small Tenrecidae hitherto referred to Oryzorictes and Microgale. Annals and magazine of natural history 14, 1918, pp. 302–307 ( [2] )
  18. ^ Henri Heim de Balsac: Insectivores. In: R. Battistini and G. Richard-Vindard (eds.): Biogeography and ecology in Madagascar. The Hague, 1972, pp. 629-660
  19. ↑ Don E. Wilson and DeeAnn M. Reeder: Title = Mammal Species of the World. A taxonomic and geographic Reference. Johns Hopkins University Press, Baltimore MD, 2005 ISBN = 0-8018-8221-4 ( [3] )

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