The Unexpected Toxicity of the Cuddly Nycticebus coucang

1. The Unexpected Toxicity of the Cuddly Nycticebus coucang By Melinda Prado Biology of Toxins May 4, 2007

2. Just Imagine… • You’re on your latest nature trek through the rainforests of southeast Asia, and you happen upon an irresistibly cute and cuddly specimen slowly making its way through the trees.

3. Thinking it’s a great Kodak moment, you try to coax the creature into the shot. But before you can say “cheese” the creature darts forward and delivers an excruciating bite to your outstretched arm. • YOU HAVE JUST BEEN ATTACKED BY THE FEROCIOUS . . .

4. . . . Slow Loris ? ? ?

5. Nycticebus coucang • The slow loris, Nycticebus coucang, is one of the few mammals considered to be venomous. • It is the only venomous primate.

6. Taxonomy • Kingdom: Animalia • Phylum: Chordata • Class: Mammalia • Order: Primates • Family: Lorisidae • Genus: Nycticebus • Species: Nycticebus coucang (Sunda Loris) Nycticebus bengalensis (Bengal Slow Loris) Nycticebus pygmaeus (Pygmy Slow Loris)

7. Slow Loris • Slow lorises are nocturnal, arboreal primates that range from Borneo and the Philippines, through Bangladesh, Vietnam, southern China, and Thailand. • Normally, they climb slowly through trees grasping branches with their well developed thumbs.However, they are capable of moving very quickly when threatened or when catching prey. • Their diet consists of insects, bird eggs, small vertebrates such as geckos, and occasionally fruit. • Slow lorises have a life span of 14-26 years.

8. Slow Loris • Adult slow lorises range in size from 21-38 cm and weigh approximately 2 kg. • They have short, thick fur found in a variety of colors, mostly reddish-brown with white or grey undertones. • Slow lorises have very powerful jaws and sharp, carnivorous teeth. • One of the most interesting physical characteristics of the slow loris is the toxin-producing gland located on the inner elbow.

9. Slow Loris Venom When feeling threatened, the slow loris will raise its arms to its head and very quickly take the toxin (which smells like sweaty socks!) from the inside of its elbows into its mouth. The small incisors of the lower jaw will conduct the toxin-laced saliva, through capillary action, into the bite wound.

10. Slow Loris Venom • Female slow lorises will also lick this toxin onto the fur of their offspring before leaving them to search for food, affording the young some protection against cats, sun bears, and civets.

11. The Toxin • Very little is known about the chemical nature of the toxin secreted from the brachial organ of the slow loris. • However, one study found that a major component of the brachial organ secretions is an 18 kDa protein composed of two 70-90 amino-acid chains linked by one or more disulfide bonds (Krane et al, 2002).

12. The Toxin • The structure of this protein is very similar to that of Fel d 1, the major allergen produced by the domestic cat, Felis catus. • Furthermore, the N-termini of these two proteins have a sequence similarity of about 70%. • Conclusion: The results indicate that the toxin produced by the slow loris is an allergen.

13. Slow Loris Bites • Following a slow loris bite, some individuals may exhibit symptoms characteristic of anaphylactic shock: • Heart problems • Cyanosis of extremities • Respiratory problems • Unconsciousness or even death • Red, itching skin • Burning tongue and throat • Hypotension • Convulsions of muscles *These symptoms further support the hypothesis that the toxin acts as an allergen.

14. Slow Loris Bites • In addition to being extremely painful, slow loris bites heal very slowly. This is mainly due to the abundance of bacteria found in the mouth of the slow loris. • There is also some risk of obtaining a virus from the slow loris bite, but fortunately rabies have never been reported in these animals.

15. Treatment • Should a slow loris bite occur, vaccination against tetanus may be recommended. The patient may also be put on antibiotics and tested for any suspected viruses. • If the patient is threatened by anaphylactic shock it may be necessary to use an emergency kit containing adrenalin, cortisone, and antihistamine.

16. Preventing a Bite • Proper handling and training by a professional can help prevent a bite by this venomous primate. • Nevertheless, when veterinarians and zoo keepers handle these animals, they usually wear elbow length elk leather gloves or stainless steel metal mesh gloves. • Slow lorises should NEVER be kept as domestic pets. Through regular contact with slow lorises, it is possible to develop an allergy to its toxin. This places the individual at risk for anaphylactic shock and even death.

17. Unfortunately the slow loris is often poached from the wild to be sold as pets (with their canines removed or filed down), or to be used for traditional Asian medicines. Competition by arboreal monkeys and destruction of habitat also present challenges to the survival of the slow loris. • Perhaps more research on this fascinating creature can provide insight on how to implement conservation programs that will help fight the decline of the slow loris.

18. References • Animal Diversity Web, University of Michigan Museum of Zoology http://animaldiversity.ummz.umich.edu/site/accounts/information/Nycticebus_coucang.html • Conservation database for lorises (Loris, Nycticebus) and pottos (Arctocebus, Perodicticus), prosimian primates http://www.loris-conservation.org/database/disease/handling_protection_of_humans_-toxin-.html • Krane, S., Itagaki, Y., Nakanishi, K., Weldon, P. 2003. “Venom” of the slow loris: sequence similarity of prosimian skin gland protein and Fel d 1 cat allergen. Naturwissenschaften. Vol 90: 60-62. • Venomdoc.com http://www.kingsnake.com/toxinology/loris/slow_loris.html • Wikipedia http://en.wikipedia.org/wiki/Slow_loris