Dwarf lesser rek

from Wikipedia, the free encyclopedia
Dwarf lesser rek
Systematics
without rank: Afroinsectiphilia
Order : Tenrecus (Afrosoricida)
Family : Tenreks (Tenrecidae)
Subfamily : Travel treks (Oryzorictinae)
Genre : Kleintenreks ( Microgale )
Type : Dwarf lesser rek
Scientific name
Microgale parvula
G. Grandidier , 1934

The Zwergkleintenrek ( Microgale parvula ) or Zwergkleintanrek is a species of mammal belonging to the genus Kleintenreks within the Tenrek family . It represents one of the smallest representatives of the genus, like all other members of the family, it is characterized by a spindle-shaped body, strong limbs and a narrow, pointed head. The tail corresponds roughly to the length of the body, the coat color is generally dark. The animals are widespread across eastern Madagascar and inhabit the tropical rainforests from the lowland areas to the high mountain levels. The altitude range of the dwarf lesser rectum is one of the most extensive within the lesser lesser aquarium. There is only limited information about the way of life of the species. It was first described scientifically in 1934 . For the next 50 years, the dwarf lesser trek was only known from the type specimen from the far north of Madagascar. It was not until the late 1980s that more animals were gradually discovered in different regions of the island. The stock is not considered endangered.

features

Habitus

The dwarf lesser rek is next to the gnome reek ( Microgale pusilla ) the smallest representative of the tenreks and one of the smallest known mammals. In general, an overall length of 11.0 to 12.8 cm, a head-trunk length of 5.0 to 6.4 cm and a tail length of 4.7 to 6.6 cm are given for the animals , the weight varies from 2.1 to 4.1 g. Investigations on five individuals from the Anosyenne Mountains in the southeast of Madagascar showed a head-trunk length of 5.0 to 6.5 cm, a tail length of 5.8 to 6.5 cm and a body weight of 3.2 to 4 , 7 g. For another six animals from the Andringitra Mountains further north, the corresponding values ​​are 5.4 to 6.4 cm or 5.5 to 6.6 cm and 2.8 to 3.9 g. In contrast, ten analyzed individuals from the Anjanaharibe and Marojejy massifs in the north of the island had a body length of 5.0 to 6.2 cm, a tail length of 5.1 to 6.6 cm and a weight of 3.0 to 4, 1 g. Like all Kleintenreks, the Zwergkleinternek is also characterized by a spindle-shaped body with short, powerful limbs and a long, narrow head that tapers at the front. The ears measure 8 to 10 mm in length, the tail is about the same size as the rest of the body. The back fur is colored dark gray-brown, individual hairs have gray bases, orange to reddish tinted upper shaft sections and brown tips. Guide hairs are somewhat flattened, but resemble the other individual hairs without the reddish shaft area in their coloring. The ventral side appears dark gray-brown. Here, single hairs also show gray bases, but brownish, reddish to yellowish brown tips. On the sides, the color of the fur on the back gradually merges with that of the underside. The tail has a uniform dark gray-brown tint, it is characterized by a scaly texture. The hair of the tail fur is short and about two and a half to three rows long, so that the tail scales are clearly visible. Front and back legs each end in five-pointed hands and feet with strong claws. The color of the hands and feet corresponds to that of the tail. The rear foot length is 9 to 11 mm. Females have one pair of teats in the chest and / or abdominal area and two pairs in the groin area, and under certain circumstances only two pairs of teats are formed in the groin area.

Skull and dentition features

The skull is small and graceful, the greatest length is 15.5 to 17.1 mm, the greatest width on the brain skull varies from 6.4 to 6.9 mm. The rostrum appears slender and long due to the backward insertion of the zygomatic arch between the second and third molars . The zygomatic arch itself is not fully developed, the anterior arch attachment does not extend beyond the last molar. The posterior area of ​​the skull is flat and also long in relation to the width of the skull. The frontal bone and the occiput are relatively large compared to the parietal bone . The joint surfaces at the beginning of the cervical spine on the occiput are slightly offset upwards and protrude prominently.

The teeth comprises 40 teeth, the dental formula is: . Short diastemas are formed in the upper row of teeth between the first incisor (I1) and the second premolar (P3) , exceptions are the second and third incisors, which are close together. In the lower jaw there is only a gap between the canine and the first premolar (P2). All front teeth have additional small cusps on the crown of the tooth, each of which is located behind the main tip. However, the upper front teeth from the second incisor to the canine also have an anterior cusp. The posterior upper premolar closely resembles the subsequent molars. These show a zalambdodonte chewing surface structure with three main cusps. In the upper jaw, the third molar is reduced in size. The upper row of teeth is 6.9 to 7.8 mm long.

distribution

Distribution area of ​​the dwarf lesser rectum

The dwarf lesser rek is endemic to Madagascar . It is distributed there in a more or less wide strip over the eastern half of the island. The most important find areas in the north include the Montagne d'Ambre , the mountain massifs of Anjanaharibe and Marojejy as well as the intermediate forest area of ​​Ambolokopatrika-Antsahamihitso, as well as the forest area of ​​Makira to the south and the Masoala peninsula to the east , all in the Antsiranana Province , and the Tsaratanana massif with the highest point on the island in Mahajanga Province . In the central-eastern part of the island, the forest area of ​​Andrivola in the province of Toamasina and the forest corridor of Anjozorobe-Angavo in the border area of ​​the provinces Toamasina and Antananarivo should be emphasized. Southern centers of distribution are found in the Ankazomivady forest area and in the Andringitra Mountains in the Fianarantsoa province and in the Anosyenne Mountains , in the Marosohy forest area and in the Vohimena Mountains in the Toliara province . In addition, isolated occurrences are documented at Ambohitantely north and at Tsinjoarivo south of Antananarivo in the province of the same name. The animals inhabit largely undisturbed, moist tropical forests in the lower to higher mountain ranges. The height distribution ranges from 450 to 2050 m above sea level, which is one of the largest ranges within the Kleintenreks. Due to this extreme height range, the dwarf lesser rek occurs sympatricly with numerous other small reek maps of eastern Madagascar , but so far hardly any ecological differentiations or niche formations between these individual species have been investigated.

Way of life

There is hardly any information on the lifestyle of the dwarf lesser rectum. The animals live in the forest and move around on the ground, their diet is based on insects according to isotope studies on individual individuals from the forest area of ​​Tsinjoarivo . A pregnant female gave birth to four embryos . Lactating females were observed several times between October and November. Ticks of the genus Ixodes appear as external parasites , while the single-cell Eimeria has been identified as internal parasites .

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 Zwergkleintenrek is a kind from the genus of microgale ( Microgale ) within the family of tenrecs (Tenrecidae). The Kleintenreks in turn belong to the subfamily of the Reistenreks , in which the rice burrowers ( Oryzorictes ) and the representatives of the genus Nesogale (Oryzorictinae) are also classified. With more than 20 species, the Kleintenreks are also the most diverse member of the Tenreks. Some morphological features make them appear originally within the family. According to molecular genetic analyzes, the genus originated in the Lower Miocene around 16.8 million years ago and diversified very strongly in the period that followed. Today's representatives have adaptations to different ways of life, so there are forms that dig underground, live above ground, or tree-climbing and water-dwelling forms. The majority of the Kleintenreks live in the damp forests of eastern Madagascar, although a few species are also found in the drier landscapes of the western part of the island. Within the genus, different kinship groups can be detected both morphologically and genetically. Externally, the Zwergkleintenrek closely resembles the Gnomkleintenrek ( Microgale pusilla ), some authors found him near the Cowan-microgale ( Microgale cowani ) and Thomas microgale ( Microgale Thomasis ). From a genetic point of view is web-footed tenrec ( Microgale mergulus ) the nearest relative of Zwergkleintenreks, which is the smallest and the largest members of the genus in a sister relationship are.

There are no known subspecies of the dwarf lesser rectum. Despite its wide distribution, no variations in terms of color or size differences between the individual populations have been observed so far . However, this can possibly be explained by the small number of examined individuals in the individual localities.

The first scientific description of the dwarf lesser rectum was made by Guillaume Grandidier in 1934. As a basis, Grandidier had a specimen that had previously been collected by E. Drouhard. Grandidier described the animal as complètement et intégralement noir (“completely black”). For the type specimen, he stated that it was a full-grown male that came from near Antsiranana in the far north of Madagascar . The specific epithet parvula is of Latin origin and means "small". In 1987, during a general revision of the Kleintenreks, Ross DE MacPhee recognized that the type specimen still represents a young animal due to the deciduous teeth. He also argued that the indication of the type location is very vague and that the named region is made up of different landscapes from dry regions to moist forest areas. Since a large part of the Kleintenreks are native to the rainforest areas of eastern Madagascar, he therefore suspected the origin of the type find in the mountain forests of the Montagne d'Ambre in the province of Antsiranana in the north of the island.

Until well into the 1980s, this individual remained the only known dwarf lesser rectum. One year after MacPhee's revision, in 1988, Paulina D. Jenkins described the species Microgale pulla based on an animal from the Forêt d'Andrivola 40 km southwest of Maroantsetra in north-eastern Madagascar (province Toamasina ), the specific epithet refers to the dark color of the fur (from Latin pullus for "dark colored"). In her first description, Jenkins stated that the animal could also possibly represent a dwarf miniscule trek in the adult stage, which among other things results in deviations in the special tooth structure in both forms. During a research expedition to the Montagne d'Ambre in 1991/1992, the dwarf treetop was observed for the first time in the mountain region. Only a little later, the species was also sighted in the Andringitra Mountains in southeastern Madagascar, which led to a significant expansion of the range. An intensive research campaign between 1994 and 1996 to study the biological diversity of Madagascar produced further evidence of the dwarf lesser rectum on the Anjanaharibe massif , the Marojejy massif and in the Anosyenne mountains, among others . After the species could already be documented by around a dozen localities in the mid-1990s, Jenkins and two fellow researchers carried out a new description of the dwarf lesser rectum in 1997. At the same time , the working group synonymous the form Microgale pulla with Microgale parvula .

Threat and protection

The greatest threats to the dwarf lesser rek are habitat losses through forest destruction as a result of conversion to arable land or when wood is removed for building material. Natural fires also have a certain impact on stocks. Due to the wide distribution and the assumed large population, the IUCN classifies the species as "not threatened" ( least concern ). It occurs in numerous nature reserves, such as the Andringitra National Park , the Andohahela National Park , the Marojejy National Park and the Montagne d'Ambre National Park .

literature

  • Guillaume Grandidier: Deux nouveaux mammifère insectivores de Madagascar Microgale drouhardi et M.parvula. Bulletin du Muséum national d'histoire naturelle (2nd series) 6, 1934, pp. 474–476 ( [2] )
  • Paulina D. Jenkins, Christopher J. Raxworthy and Ronald A. Nussbaum: A new species of Microgale (Insectivora, Tenrecidae), with comments on the status of four other taxa of shrew tenrecs. Bulletin of the Natural History Museum of London (Zoology) 63 (1), 1997, pp. 1-12
  • 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. 168) ISBN 978-84-16728-08-4

Individual evidence

  1. ↑ a b c d e f g h i Paulina D. Jenkins, Christopher J. Raxworthy and Ronald A. Nussbaum: A new species of Microgale (Insectivora, Tenrecidae), with comments on the status of four other taxa of shrew tenrecs. Bulletin of the Natural History Museum of London (Zoology) 63 (1), 1997, pp. 1-12
  2. ↑ Steven M. Goodman and Voahangy Soarimalala: A new species of Microgale (Lipotyphla: Tenrecidae: Oryzorictinae) from the Forêt des Mikea of ​​southwestern Madagascar. Proceedings of the Biological Society of Washington 117 (3), 2004, pp. 251-265
  3. ↑ 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
  4. ↑ a b c d e f g 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
  5. ↑ a b c d e Steven M. Goodman and Paulina D. Jenkins: The Insectivores of the Réserve Spéciale d'Anjanaharibe-Sud, Madagascar. Fieldiana Zoology 90, 1998, pp. 139-161
  6. ↑ a b c d e Steven M. Goodman and Paulina D. Jenkins: Tenrecs (Lipotyphla; Tenrecidae) of the Parc National de Marojejy, Madagascar. Fieldiana Zoology 97, 2000, pp. 201-229
  7. ↑ a b c d e Paulina D. Jenkins: A New Species of Microgale (Insectivora: Tenrecidae) from Northeastern Madagascar. American Museum Novitates 2910, 1988, pp. 1-7
  8. ↑ 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. 168) ISBN 978-84-16728-08-4
  9. ↑ a b Christopher J. Raxworthy and Ronald A. Nussbaum: A rainforest survey of amphibians, reptiles and small mammals at Amber Mountain, Madagascar. Biological Conservation 69, 1994, pp. 65-73
  10. ^ Franco Andreone, Jasmin E. Randrianirina, Paula D. Jenkins and Gennaro Aprea: Species diversity of Amphibia, Reptilia and Lipotyphla (Mammalia) at Ambolokopatrika, a rainforest between the Anjanaharibe-Sud and Marojejy massifs, NE Madagascar. Biodiversity and Conservation 9, 2000, pp. 1587-1622
  11. ↑ 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
  12. ↑ Zafimahery Rakotomalala, Vonjy Andrianjakarivelo, Volatiana Rasataharilala and Steven M. Goodman: Les petits mammifères non volant de la forêt de Makira, Madagascar. Bulletin de la Société zoologique de France 132, 2007, pp. 205-221
  13. ↑ Vonjy Andrianjiakarivelo, Emilienne Razafimahatratra, Yvette Razafindrakoto and Steven M. Goodman: The terrestrial small mammals of the Parc National de Masoala, northeastern Madagascar. Acta Theriologica 50 (4), 2005, pp. 537-549
  14. ↑ Voahangy Soarimalala: Exploitation des bois à précieux Masoala, Madagascar: quel impact sur les tenrecs? Afrotherian Conservation 14, 2018, pp. 20–32
  15. ↑ Claudette Patricia Maminirina, Steven M. Goodman and Christopher J. Raxworthy: Les micro-mammifères (Mammalia, Rodentia, Afrosoricida et Soricomorpha) du du massif Tsaratanana et biogeography of Forests de montagnes de Madagascar. Zoosystema 30, 2008, pp. 695-721
  16. ↑ Voahangy Soarimalala, Landryh T. Ramanana, José M. Ralison and Steven M. Goodman: Les petits mammifères non-volants du “Couloir forestier d'Anjozorobe - Angavo”. In: Steven M. Goodman, Achille P. Raselimanana and Lucienne Wilmé (eds.): Inventaires de la faune et de la flore du couloir forestier d'Anjozorobe - Angavo. Recherche pour le développement, Série Sciences biologiques, Center d'Information et de Documentation Scientifique et Technique 24, 2007, pp. 141-182
  17. ↑ Steven M. Goodman, Jean-Marc Duplantier, Pierre Jules Rakotomalaza, Achille Philippe Raselimalala, Rodin Rasoloarinson, Mamy Ravokatra, Voahangy Soarimalala and Lucienne Wilmé: Inventaire biologique de la Forêt d'Ankazomivady, Ambositra. Akon'ny Ala 24, 1998, pp. 19-32
  18. ↑ 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
  19. ↑ Steven M. Goodman and Daniel Rakotondravony: The effect of forest fragmentation and isolation on insectivorous small mammals (Lipotyphla) on the Central High Plateau of Madagascar. Journal of Zoology 250, 2000, pp. 193-200
  20. ↑ 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
  21. ^ A b P. J. Stephenson, Voahangy Soarimalala and Steven M. Goodman: Microgale parvula. The IUCN Red List of Threatened Species 2016. e.T13349A97201228 ( [1] ); last accessed on August 19, 2016
  22. ↑ 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
  23. ↑ Dmitry A. Apanaskevich, Voahangy Soarimalala and Steven M. Goodman: A new Ixodes species (Acari: Ixodidae), parasite of Shrew tenrecs (Afrosoricida: Tenrecidae) in Madagascar. Journal of Parasitology 99 (6), 2013, pp. 970-972
  24. ↑ Lee Couch, Juha Laakkonen, Steven Goodman, and Donald W. Duszynski: Two New Eimerians (Apicomplexa) from Insectivorous Mammals in Madagascar. Journal of Parasitology 97 (2), 2011, pp. 293-296
  25. ↑ 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
  26. ^ JF Eisenberg and Edwin Gould: The Tenrecs: A Study in Mammalian Behavior and Evolution. Smithsonian Institution Press, 1970, pp. 1-138
  27. ↑ a b c 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
  28. ↑ Guillaume Grandidier: Deux nouveaux mammifère insectivores de Madagascar Microgale drouhardi et M. parvula. Bulletin du Muséum national d'histoire naturelle (2e Série) 6, 1934, pp. 474–476

Web links