• Ruqayya Khan

Why the long face?

The South American tapir, Tapirus terrestris, is the largest surviving native terrestrial mammal in the Amazon. Although tapirs are physically similar to pigs, they are actually an odd-toed ungulate that's more closely related to horses and rhinoceroses [1]. South American tapirs primarily forage and consume vegetation native to the Amazon, including fruits like the mombin and the huito [2].


As in other tapir species, the South American tapir's nose and upper lip combine into a flexible snout like an elephant's trunk. The elongated nose is not just for show! The tapir makes up for their relatively poor eyesight with their strong sense of smell, helping them to locate food and potential mates. Their trunks are also prehensile, meaning they're able to grip tree branches to clear off fruit and leaves.

The ICUN categorizes the South American tapir as vulnerable with its population in declining trend. The biggest threats to the South American tapir are similar to many Amazonian species: habitat loss to logging and poaching their meat and hides [3]. Natural predators of the tapir are jaguars and crocodiles. In a threatening situation, tapirs may emit a high pitched squealing noise. Additionally, tapirs are great swimmers and may escape from predators by swimming away while using their magnificent snouts as snorkels [4].

South American Tapir (Tapirus terrestris) by Allan Hopkins, [CC BY-NC-ND 2.0], via flickr.com

Today we share the chromosome-length assembly for the South American tapir. This is a $1K genome assembly with contig N50 = 46 Kb and scaffold N50 = 47 Mb (see Dudchenko et al., 2018 for procedure details). The genome was generated using a sample from the T.C. Hsu Cryo-Zoo at the University of Texas MD Anderson Cancer Center stored all the way back in 1977! We thank Drs. Asha Multani, Sen Pathak, Richard Behringer, Liesl Nel-Themaat and Arisa Furuta in the Department of Genetics at the MD Anderson Cancer Center for their help with this sample.

This is the second tapir species in our collection of genome assemblies (out of four recognized extant species of tapir). Check out this blog post and assembly page for the Malayan tapir, the only Old-World species of tapir. Interestingly, the species are hugely different in terms of karyotype: the Malayan tapir has a karyotype of 2n=52 whereas the South American Tapir has a karyotype of 2n=80! Check out the whole genome alignment plot below to find all the chromosomal breaks between the two.

Whole-genome alignment plot between Tapirus_terrestris_HiC and Tapirus_indicus_HiC

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