Bergerak hati-hati, pelan, dan anti grasa grusu. Kukang (Slow loris) tidak didesain untuk berburu, namun untuk bertahan. Kukang memakan getah pohon, buah, dan serangga kecil. Sumber makanannya ini rendah kalori dan sulit dicerna sehingga mengharuskannya hemat energi. Makanya geraknya slow, karena gerakan gesit seperti para predator itu perlu banyak tenaga.
Mamalia yang menyusui anaknya ini bertahan dengan bisa atau racun yang akan dimasukkan ke aliran darah musuhnya melalui gigitan. Jadi hewan ini disebut berbisa atau venomous seperti ular, kalajengking, dan platypus. Familiar dengan kesamaan mereka? Hewan-hewan berbisa perlu suatu alat untuk memasukan racun mereka ke tubuh musuhnya. Ular dengan suntikan taringnya, kalajengking dengan sengat di ekornya (Aculeus), dan platypus dengan taji (spur) di kaki belakangnya (Gambar 1).
Inilah yang membedakan hewan berbisa (venomous) dengan hewan beracun (poisonous). ‘Bisa’ perlu untuk masuk ke aliran darah melalui gigitan atau suntikan untuk dapat bereaksi, sedangkan hewan yang beracun dapat memberi efek hanya dengan menyentuh atau memakannya. Seperti katak berwarna cerah (poison dart frog: Dendrobatidae) yang terkenal dapat membunuh siapa yang menyentuhnya.
Nah, kukang dengan gigitannya akan membuat musuhnya merasa nyeri, meradang, menyebabkan reaksi alergi berat yang dapat menyebabkan manusia pingsan. Sehingga kukang dikategorikan sebagai hewan berbisa atau venomous. Ini menarik karena ‘bisa’ sangat tidak umum untuk mamalia. Menurut Nekaris et al. (2013) corak garis hitam yang membentang dari kepala menuju ke ekor, gigitan berbisa, dan sifat-sifat lain yang ‘mirip ular’ ini menunjukkan kukang mungkin mengembangkan mimikri Müllerian yaitu strategi meniru ular kobra (Naja sp.) (Gambar 2).
Kukang memiliki gigi depan bawah dengan struktur 6 gigi seri yang miring ke depan seperti sisir (Toothcomb) (Gambar 3).
Kukang akan menggigit musuhnya, kemudian gigi sisir yang rapat membentuk alur membantu mengalirkan bisa dengan prinsip kapilaritas (Gambar 4). Prinsip fisika ini memungkinkan cairan mengalir atau naik melalui celah-celah sempit karena adanya adhesi antar molekul (Nekaris et al. 2013).
Oh iya, kamu nggak akan kena dampak venomous-nya kalau kukang gigit kamu tapi belum melakukan ini. Kukang harus menjilati kelenjar minyak yang ada diketiaknya (Gambar 5) terlebih dahulu. Karena bisa kukang baru sepenuhnya aktif ketika eksudat atau minyak dari ketiaknya dicampur dengan saliva atau air liur kukang. Kandungan senyawa beracun pada kelenjar ketiak dan saliva kukang kemungkinan berasal dari apa yang ia makan yaitu getah-getah tumbuhan yang punya efek racun (Fitzpatrick et al. 2023). Namun ada pula senyawa racun yang tubuh kukang hasilkan sendiri karena meskipun berada dalam kandang dengan pola makan tanpa getah, kukang tetap bisa menghasilkan gigitan yang beracun (Nekaris et al. 2020).
Jadi, apasih sebenarnya kandungan bisa kukang yang membuat salah satu Alobi ranger pernah masuk UGD. Sebetulnya bagaimana mekanisme pasti dari bisa/venom kukang ini masih belum bisa dipastikan oleh para peneliti. Uniknya Nekaris et al. 2013 menunjukkan adanya protein Fel-D1 (Gambar 6), ini merupakan senyawa alergen kucing!.
Kalau ada orang yang alergi kucing, itu karena protein ini banyak terkandung di air liurnya. Senyawa alergen seperti Fel-D1 akan mengaktifkan respon imun tubuh, dan ketika efeknya parah (anafilaksis) dapat menyebabkan tubuh melepas histamin besar-besaran membuat tekanan darah turun drastis, saluran nafas menyempit, otak kekurangan oksigen, sehingga pingsan (Krane et al. 2003; Inoue 2021).
Selain itu, ada ratusan senyawa lainnya yang bervariasi antar spesies namun peneliti menyimpulkan bahwa bisa kukang bersifat kompleks karena merupakan campuran dari zat aktif protein dan metabolit sekunder (Fitzpatrick et al. 2023).
Menariknya ternyata kukang juga melindungi bayinya dengan bisa ini. Saat ibu kukang mau mencari makan, ia akan meninggalkan anaknya di pohon. Kemudian untuk melindunginya , ibu kukang menjilati tubuh anaknya. Setelah lebih dulu menjilati ketiak tentunya. Ini akan membuat bau tubuh anaknya terasa berbahaya bagi predator, dan memberi perlindungan layaknya ‘tameng racun’ bagi predator yang mencoba memakan anaknya. Ingat mengenai perbedaan berbisa (venomous) dan beracun (poisonous)?.
Sayangnya kukang yang ada di Pulau Bangka (Nycticebus bancanus) (Gambar 7), merupakan jenis yang oleh IUCN (Internasional Union for Conservation of Nature) dikategorikan sebagai terancam kritis. Artinya kukang bangka sangat terancam punah, sehingga menjadi hewan yang dilindungi dan dilarang untuk diperdagangkan. Di tengah masifnya kehilangan habitatnya karena tingkat deforestasi yang mengkhawatirkan (Auriga Nusantara 2024), kukang perlu kita perhatikan. Oleh karena itu, Alobi wildlife rescue and research center berkomitmen untuk melestarikan kukang melalui kegiatan penyelamatan, penelitian, dan edukasi. Pusat penyelamatan satwa Alobi Babel II akan dibuka untuk berfokus pada dua jenis satwa endemik Bangka yaitu Mentilin (Cephalopacus bancanus) dan Kukang Bangka (Nycticebus bancanus).
Kamu bisa jadi bagian dari misi ini dengan berbagi informasi, donasi, atau menjadi volunteer. Cek website Alobi untuk info lebih lanjut.
Jangan lupa, tetap penasaran!
Salam lestari.
Datar Pustaka:
Auriga Nusantara. 2025. “Status of Deforestation in Indonesia 2024.” Simontini. Diakses 30 Mei 2025. https://simontini.id/en/status-of-deforestation-in-indonesia-2024
Braun RL, Sachett LG, Pol-Fachin L, Verli H.2015. The Calcium Goes Meow: Effects of Ions and Glycosylation on Fel d 1, the Major Cat Allergen.Frontiers in Allergy 4:1-9. https://doi.org/10.3389/falgy.2024.1291871.
Fitzpatrick LLJ, Ligabue‑Braun R, Nekaris KAI.2023. Slowly Making Sense: A Review of the Two‑Step Venom System within Slow (Nycticebus spp.) and Pygmy Lorises (Xanthonycticebus spp.). Toxins, 15(9): 1-28. https://doi.org/10.3390/toxins15090514
Inoue, F., Inoue, A., & Takayama, M. (2021). Severe anaphylactic shock following a slow loris bite in a patient with cat allergy. Internal Medicine 60(18):2779–2783. https://doi.org/10.2169/internalmedicine.6775-20
Krane S, Itagaki Y, Nakanishi K, Weldon PJ.2003. “Venom” of the slow loris: Sequence similarity of prosimian skin gland protein and Fel d 1 cat allergen. Naturwissenschaften 90:60–62. https://doi.org/10.1007/s00114-002-0394-z.
Rode‑Margono EJ, Nekaris KAI.2015.Gastrointestinal parasites and ectoparasites in wild Javan slow loris (Nycticebus javanicus), and implications for captivity and animal rescue. Journal of Zoo and Aquarium Research, 3(3): 80–86. https://doi.org/10.19227/jzar.v3i3.86.
Nekaris KAI, Moore RS, Rode EJ, Fry BG.2020. Mad, bad and dangerous to know: The biochemistry, ecology and evolution of slow loris venom. Toxins, 12(2):1-10. https://doi.org/10.3390/toxins12020105.
Penulis: Frista Chairunnisa
Editor: Langka Sani
The Science Behind the Slow Loris Bite That Can Send You to the ER
Writer: Frista Chairunnisa
Editor: Langka Sani
Moving carefully, slowly, and never in a rush. The slow loris is not designed for hunting, but for surviving. It feeds on tree sap, fruit, and small insects. These food sources are low in calories and hard to digest, which means the slow loris must conserve energy. That’s why it moves slowly, unlike predators whose swift movements require a lot of energy.
This mammal, which nurses its young, defends itself with venom that enters an enemy’s bloodstream through its bite. That’s why the slow loris is considered venomous, just like snakes, scorpions, and the platypus. Sound familiar? Venomous animals need a specialized mechanism to deliver their toxins. Snakes use their fangs, scorpions use the sting at the tip of their tail (the aculeus), and platypuses have a spur on their hind legs (see Figure 1).
This is what distinguishes venomous animals from poisonous ones. Venom must be injected through a bite or a stingto take effect, while poisonous animals can cause harm simply by being touched or ingested. For example, brightly colored frogs (poison dart frogs, Dendrobatidae) are well-known for their ability to kill anyone who touches them.
A slow loris, through its bite, can cause pain, inflammation, and severe allergic reactions that may even lead to unconsciousness in humans. That’s why it is classified as a venomous animal. This is particularly fascinating because venom is extremely rare among mammals. According to Nekaris et al. (2013), the black stripe running from the head to the tail, its venomous bite, and other ‘snake-like’ traits suggest that the slow loris may have developed Müllerian mimicry, a survival strategy in which it imitates venomous snakes such as cobras (Naja spp.) (see Figure 2).
The slow loris has lower front teeth arranged in a forward-tilting comb-like structure consisting of six incisors, known as a toothcomb (see Figure 3).
When the slow loris bites, its tightly packed comb-like teeth create small grooves that help the venom flow using capillary action (see Figure 4). This is a physics principle where liquid moves through tiny spaces thanks to the adhesive force between molecules (Nekaris et al., 2013).
You won’t be affected by the venom just from a slow loris bite, unless it does this first. The slow loris must lick a gland located in its armpit (see Figure 5) beforehand. The venom only becomes fully active when the exudate or oil from the armpit gland is mixed with the loris’s saliva. The toxic compounds in the armpit gland and saliva are likely derived from its diet, especially plant saps that have toxic properties (Fitzpatrick et al., 2023). However, some toxic substances are believed to be produced endogenously by the slow loris itself, as it can still deliver a venomous bite even when kept in captivity on a sap-free diet (Nekaris et al., 2020).
So, what exactly is in the slow loris venom that once sent an Alobi ranger to the emergency room? In fact, the exact mechanism of slow loris venom is still not fully understood by researchers. Interestingly, Nekaris et al. (2013) identified the presence of a protein similar to Fel-D1 (see Figure 6), a well-known allergenic compound found in cats!
If someone is allergic to cats, it’s usually because this protein (Fel-D1) is found in high concentrations in cat saliva. Allergenic compounds like Fel-D1 trigger the body’s immune response, and in severe cases (anaphylaxis), they can cause a massive release of histamine. This leads to a dangerous drop in blood pressure, constriction of airways, lack of oxygen to the brain, and loss of consciousness (Krane et al., 2003; Inoue, 2021).
In addition to Fel-D1, slow loris venom contains hundreds of other compounds that vary between species. Researchers have concluded that slow loris venom is complex, consisting of a mixture of active proteins and secondary metabolites (Fitzpatrick et al., 2023).
Interestingly, slow lorises also use their venom to protect their babies. When a mother leaves her infant to forage, she licks her armpit gland first and then grooms her baby—coating the infant’s fur with venom. This makes the baby smell dangerous to predators, acting like a “poison shield” against anything that might try to eat it. Remember the difference between venomous and poisonous animals? This is where it becomes relevant.
Unfortunately, the slow loris species found on Bangka Island (Nycticebus bancanus) (See Figure 7) is listed as Critically Endangered by the International Union for Conservation of Nature (IUCN). This means the Bangka slow loris faces an extremely high risk of extinction and is legally protected—it must not be captured or traded. With its habitat under threat due to alarming rates of deforestation (Auriga Nusantara, 2024), the species needs our attention and care.
That’s why the Alobi Wildlife Rescue and Research Center is committed to conserving slow lorises through rescue, research, and education. The new Alobi Babel II rescue center will focus specifically on two endemic Bangka species: the Mentilin (Cephalopachus bancanus) and the Bangka slow loris (Nycticebus bancanus).
You can be part of this mission by spreading awareness, donating, or volunteering. Visit the Alobi website for more information.
And remember, stay curious!
Reference
Auriga Nusantara. 2025. “Status of Deforestation in Indonesia 2024.” Simontini. Accesed 30 May 2025. https://simontini.id/en/status-of-deforestation-in-indonesia-2024
Braun RL, Sachett LG, Pol-Fachin L, Verli H.2015. The Calcium Goes Meow: Effects of Ions and Glycosylation on Fel d 1, the Major Cat Allergen.Frontiers in Allergy 4:1-9. https://doi.org/10.3389/falgy.2024.1291871.
Fitzpatrick LLJ, Ligabue‑Braun R, Nekaris KAI.2023. Slowly Making Sense: A Review of the Two‑Step Venom System within Slow (Nycticebus spp.) and Pygmy Lorises (Xanthonycticebus spp.). Toxins, 15(9): 1-28. https://doi.org/10.3390/toxins15090514
Inoue, F., Inoue, A., & Takayama, M. (2021). Severe anaphylactic shock following a slow loris bite in a patient with cat allergy. Internal Medicine 60(18):2779–2783. https://doi.org/10.2169/internalmedicine.6775-20
Krane S, Itagaki Y, Nakanishi K, Weldon PJ.2003. “Venom” of the slow loris: Sequence similarity of prosimian skin gland protein and Fel d 1 cat allergen. Naturwissenschaften 90:60–62. https://doi.org/10.1007/s00114-002-0394-z.
Rode‑Margono EJ, Nekaris KAI.2015.Gastrointestinal parasites and ectoparasites in wild Javan slow loris (Nycticebus javanicus), and implications for captivity and animal rescue. Journal of Zoo and Aquarium Research, 3(3): 80–86. https://doi.org/10.19227/jzar.v3i3.86.
Nekaris KAI, Moore RS, Rode EJ, Fry BG.2020. Mad, bad and dangerous to know: The biochemistry, ecology and evolution of slow loris venom. Toxins, 12(2):1-10. https://doi.org/10.3390/toxins12020105.
