Tenrec

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Family of small mammals

title: "Tenrec" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["afrosoricida", "endemic-fauna-of-madagascar", "mammals-of-madagascar", "extant-eocene-first-appearances", "animals-that-use-echolocation", "taxa-named-by-john-edward-gray"] description: "Family of small mammals" topic_path: "general/afrosoricida" source: "https://en.wikipedia.org/wiki/Tenrec" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Family of small mammals ::

| name = Tenrecidae | fossil_range = | image = Tanrek.jpg | image_caption = Tailless tenrec (Tenrec ecaudatus) | taxon = Tenrecidae | authority = Gray, 1821 | type_genus = Tenrec | type_genus_authority = Lacépède, 1799 | subdivision_ranks = Subfamilies | subdivision = * Geogalinae

A tenrec () is a mammal belonging to any species within the afrotherian family Tenrecidae, which is endemic to Madagascar. Tenrecs are a very diverse group, as a result of adaptive radiation, and exhibit convergent evolution; some resemble hedgehogs, shrews, opossums, rats, or mice. They occupy aquatic, arboreal, terrestrial, and fossorial environments. Some of these species, including the greater hedgehog tenrec, can be found in the Madagascar dry deciduous forests. However, the speciation rate in this group has been higher in humid forests.

All tenrecs are believed to descend from a common ancestor that lived 29–37 million years ago after rafting over from Africa. The split from their closest relatives, African otter shrews, is estimated to have occurred about 47–53 million years ago.

Etymology

The word "tenrec" is borrowed, via French, from the Malagasy word tandraka (variant of trandraka), which refers to the tailless tenrec (Tenrec ecaudatus); the Malagasy word may be related to .

Evolution

Tenrecs are believed to have evolved from a single species that colonized Madagascar between 42 and 25 million years ago. The question of how this family reached Madagascar is still unresolved, but the leading hypothesis suggests a small number of individuals may have found themselves on floating vegetation and crossed the Mozambique Channel, which separates Madagascar from southeastern Africa. The Tenrecidae family is one of only four extant terrestrial mammal lineages to have colonized and diversified on Madagascar.

Once established on Madagascar, tenrecs diversified to occupy various niches on the island. Many evolved resemblances to familiar but unrelated mammals that are not found on Madagascar. For instance, the two species of hedgehog tenrec possess coats of hardened spines and the ability to roll into a ball when threatened, characteristics similar to those of true hedgehogs. This example, along with others, demonstrates convergent evolution; it has provided evolutionary biologists with opportunities to study adaptation over evolutionary timescales.

Characteristics

Tenrecs are small mammals of variable body form. The smallest species are the size of shrews, with a body length of around 4.5 cm, and weighing just 5 g, while the largest, the common or tailless tenrec, is 25 to in length, and can weigh over 1 kg. Although they may resemble shrews, hedgehogs, or opossums, they are not closely related to any of these groups, their closest relatives being the otter shrews, and after that other African insectivorous mammals including golden moles and elephant shrews. The common ancestry of these animals, which are classified together in the clade Afrotheria, was not recognized until the late 1990s. Continuing work on the molecular{{Cite journal | title=Molecules consolidate the placental mammal tree | journal=Trends Ecol Evol | year=2004 | volume=19 | issue=8 | pages=430–438 | pmid=16701301 |author=Springer, M.S.; Stanhope, M.J.; Madsen, O.; de Jong, W.W. | doi=10.1016/j.tree.2004.05.006 | s2cid=1508898 }}{{Cite journal | year=2004 | title=Cross-species chromosome painting in the golden mole and elephant-shrew: support for the mammalian clades Afrotheria and Afroinsectiphillia but not Afroinsectivora | journal=Proceedings of the Royal Society B | volume=271 | issue=1547 | pages=1477–1484 | doi=10.1098/rspb.2004.2754 | author=Robinson, T. J.; Fu, B.; Ferguson-Smith, M. A.; Yang, F. | pmid=15306319 | pmc=1691750 }} and morphological{{Cite journal | year=2009 | title=The new framework for understanding placental mammal evolution | journal=BioEssays | volume=31 | issue=8 | pages=853–864 | pmid=19582725 |author1=Asher, R.J. |author2=Bennet, N. |author3=Lehmann, T. | doi=10.1002/bies.200900053 | s2cid=46339675 | doi-access=free}}{{Cite journal | title=Early tertiary mammals from North Africa reinforce the molecular Afrotheria clade | journal=Proceedings of the Royal Society B | year=2007 | volume=274 | issue=1614 | pages=1159–1166 | doi=10.1098/rspb.2006.0229 | last1=Tabuce | first1=R. | last2=Marivaux | first2=L. | last3=Adaci | first3=M. | last4=Bensalah | first4=M. | last5=Hartenberger |first5=J.-L. |first6=M. |last6=Mahboubi |first7=F. |last7=Mebrouk |first8=P. |last8=Tafforeau |first9=J.-J. |last9=Jaeger |display-authors=3 | pmid=17329227 | pmc=2189562}} diversity of afrotherian mammals has provided ever increasing support for their common ancestry.

Tenrecs are among the few terrestrial mammals that echolocate. Unusual among placental mammals, the rectum and urogenital tracts of tenrecs share a common opening, or cloaca which is a feature more commonly seen in birds, reptiles, and amphibians. They have a low body temperature, sufficiently low that they do not require a scrotum to cool their sperm as do most other mammals.

All species appear to be at least somewhat omnivorous, with invertebrates forming the largest part of their diets. One species, Microgale mergulus, is semiaquatic (similar to the lifestyle of their closest relatives, the otter shrews).{{Cite book |author1=Benstead, J. P. |author2=Olson, L. E. | chapter=Limnogale mergulus, web-footed tenrec or aquatic tenrec | year=2003 | pages=1267–1273 |editor1=S. M. Goodman |editor2=J. P. Benstead | publisher=University of Chicago Press | location=Chicago | isbn=978-0-226-30307-9 | title=The natural history of Madagascar

Most species are nocturnal and have poor eyesight. Their other senses are well developed, however and they have especially sensitive whiskers. As with many of their other features, the dental formula of tenrecs varies greatly between species; they can have from 32 to 42 teeth in total. Unusual for mammals, the permanent dentition in tenrecs tends not to completely erupt until well after adult body size has been reached.{{Cite journal | year=2008 | title=Dental eruption in afrotherian mammals | journal=BMC Biology | volume=6 | doi=10.1186/1741-7007-6-14 | author1=Asher, R. J. |author2=Lehmann, T. | article-number=14 | pmid=18366669 | pmc=2292681 | doi-access=free }} This is one of several anatomical features shared by elephants, hyraxes, sengis, and golden moles (but apparently not aardvarks), consistent with their descent from a common ancestor.

Tenrecs have a gestation period of 50 to 64 days, and give birth to a number of relatively undeveloped young. While the otter shrews have just two young per litter, the tailless tenrec can have as many as 32, and females possess up to 29 teats, more than any other mammal. Some tenrec species are social, living in multigenerational family groups with over a dozen individuals.

Interaction with humans

::figure[src="https://upload.wikimedia.org/wikipedia/commons/b/bd/Tailless_Tenrec_prepared_for_cooking.jpg" caption="[[Tailless tenrec]] (''Tenrec ecaudatus'') prepared for cooking in a Malagasy [[kitchen]]."] ::

In the island nation of Mauritius, and also on the Comoran island of Mayotte, some of the inhabitants eat tenrec meat, although it is difficult to obtain (as it is not sold in shops or markets) and difficult to prepare correctly.

The lesser hedgehog tenrec (Echinops telfairi) is one of 16 mammalian species that will have its genome sequenced as part of the Mammalian Genome Project. It is increasingly popular in the pet trade, and in the future may serve as an important model organism in biomedicine, as it is only distantly related to the mice, rats, guinea pigs and rhesus macaques which comprise the most common research animals.

Threats

Of the 31 species assessed, 24 (77%) are categorized by the IUCN Red List as least concern, one species as data deficient, four species as vulnerable, and two species as endangered.

The conservation status of many tenrec species is of concern due to an increase of threats within the last 50 years. The main threats facing them include habitat loss due to deforestation, fragmentation, and degradation; hunting; incidental capture; and climate change. Slash-and-burn agriculture, commercial logging, and mining of metals are negatively affecting tenrec species that inhabit forests. Five of the six threatened tenrec species are dependent on forest habitats.

Conservation

As of 2022, conservation of the tenrec population is not being prioritized. Because most tenrecs are dependent on forest habitats, conservation efforts would need to include a focus on reduction in deforestation on Madagascar, as well as habitat restoration. Current conservation efforts include that of the Madagascar Ankizy Fund, started by a paleontological team from Stony Brook University, to improve access to health care and education facilities for villagers in remote areas of Madagascar. A healthy and educated local human population, in the long term, will benefit the Malagasy fauna, such as tenrecs.

Species

The three subfamilies, eight genera, and 31 extant species of tenrecs are:

FAMILY TENRECIDAE

References

References

  1. Pickford, Martin. (2015). "Late Eocene Potamogalidae and Tenrecidae (Mammalia) from the Sperrgebiet, Namibia". Communications of the Geological Survey of Namibia.
  2. Olson, Link E.. (2013). "Tenrecs". Current Biology.
  3. (2013). "Tenrecs". Current Biology.
  4. Kinver, M.. (2010-01-20). "Mammals 'floated to Madagascar'". [[BBC]].
  5. Ali, J. R.. (2010-01-20). "Mammalian biodiversity on Madagascar controlled by ocean currents". [[Nature (journal).
  6. (2016). "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.
  7. (2002). "Molecular Evidence for the Monophyly of Tenrecidae (Mammalia) and the Timing of the Colonization of Madagascar by Malagasy Tenrecs". Molecular Phylogenetics and Evolution.
  8. (2008). "Molecular phylogeny and divergence times of Malagasy tenrecs: Influence of data partitioning and taxon sampling on dating analyses". BMC Evolutionary Biology.
  9. (2021). "tenrec". Merriam-Webster.
  10. "Rakibolana malagasy sy Rakipahalalana momba an' i Madagasikara : trandraka".
  11. (2011). "11th International Conference on Austronesian Linguistics".
  12. (2016-04-21). "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.
  13. Nicholl, Martin. (1984). "The Encyclopedia of Mammals". Facts on File.
  14. (1998). "Molecular evidence for multiple origins of Insectivora and for a new order of endemic African insectivore mammals". PNAS.
  15. Seiffert, E.. (2007). "A new estimate of afrotherian phylogeny based on simultaneous analysis of genomic, morphological, and fossil evidence". BMC Evolutionary Biology.
  16. Sanchez-Villagra, M. R., Narita, Y. and Kuratani, S.. (2007). "Thoracolumbar vertebral number: the first skeletal synapomorphy for afrotherian mammals". Syst Biodivers.
  17. Gould, Edwin. (1965). "Evidence for echolocation in the Tenrecidae of Madagascar". Proceedings of the American Philosophical Society.
  18. Yin, Steph. (29 June 2018). "The Evolutionary Origin of Descending Testicles". The New York Times.
  19. (2003). "The Natural History of Madagascar". Chicago University Press.
  20. (2008). "Molecular phylogeny and divergence times of Malagasy tenrecs: influence of data partitioning and taxon sampling on dating analyses". BMC Evolutionary Biology.
  21. (2006). "Tenrec phylogeny and the noninvasive extraction of nuclear DNA". Systematic Biology.
  22. (Jan 2021). "Review of the status and conservation of tenrecs (Mammalia: Afrotheria: Tenrecidae)". Oryx.
  23. "Afrotherian Conservation {{!}} IUCN Afrotheria Specialist Group".
  24. {{MSW3 Bronner

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afrosoricidaendemic-fauna-of-madagascarmammals-of-madagascarextant-eocene-first-appearancesanimals-that-use-echolocationtaxa-named-by-john-edward-gray