Clinical Toxinology Resources Home
Enhydris matannensis
General Details, Taxonomy and Biology, Venom, Clinical Effects, Treatment, First Aid , Antivenoms
Family: Homalopsidae
Genus: Enhydris
Species: matannensis
Common Names
Boulenger's Water Snake , Matanna Water Snake
Southeast Asia
Taxonomy and Biology
Adult Length: 0.35 m
General Shape
Small in length, cylindrical, stout bodied snake with a moderately short tail. Few recorded specimens. Can grow to a maximum of at least 0.49 metres ( few recorded specimens ). Head is depressed and slightly distinct from neck. Eyes are small in size with vertically elliptical pupils. Nostrils are small, valvular, crescent shaped and located anterodorsally. Dorsal scales are smooth. Ventrals are rounded without keels. Dorsal scale count 21 - 21 - 19.
Freshwater lowland streams near coast, irrigation canals and rice paddies.
Aquatic and species.
Feeds mainly on fish, frogs and tadpoles.
Species Map
Small (Approx 20k) version
General: Venom Neurotoxins
General: Venom Myotoxins
General: Venom Procoagulants
General: Venom Anticoagulants
General: Venom Haemorrhagins
General: Venom Nephrotoxins
General: Venom Cardiotoxins
General: Venom Necrotoxins
General: Venom Other
Clinical Effects
General: Dangerousness
Not likely to cause significant effects; non-lethal
General: Rate of Envenoming: Non-venomous, so essentially all bites should be "dry".
General: Untreated Lethality Rate: No lethal potential, non-venomous bite
General: Local Effects
Insufficient clinical reports to know, but most likely no local effects, possibly, at most, minor local pain & swelling only
General: Local Necrosis
Insufficient clinical reports to know, but local necrosis most unlikely
General: General Systemic Effects
Insufficient clinical reports to know, but systemic effects not expected
General: Neurotoxic Paralysis
Insufficient clinical reports to know, but unlikely to occur
General: Myotoxicity
Insufficient clinical reports to know, but unlikely to occur
General: Coagulopathy & Haemorrhages
Insufficient clinical reports to know, but unlikely to occur
General: Renal Damage
Insufficient clinical reports to know, but unlikely to occur
General: Cardiotoxicity
Insufficient clinical reports to know, but unlikely to occur
General: Other
Insufficient clinical reports to know
First Aid
Description: First aid for bites by non-front-fanged colubroid snakes likely to cause either no effects or only mild local effects.
1. After ensuring the patient and onlookers have moved out of range of further strikes by the snake, the bitten person should be reassured and persuaded to lie down and remain still. Many will be terrified, fearing sudden death and, in this mood, they may behave irrationally or even hysterically. The basis for reassurance is the fact that many venomous bites do not result in envenoming, the relatively slow progression to severe envenoming (hours following elapid bites, days following viper bites) and the effectiveness of modern medical treatment.
2. The bite wound should not be tampered with in any way. Wiping it once with a damp cloth to remove surface venom is unlikely to do much harm (or good) but the wound must not be massaged.
3. All rings or other jewellery on the bitten limb, especially on fingers, should be removed, as they may act as tourniquets if oedema develops.
4. The bitten limb should be immobilised as effectively as possible using an extemporised splint or sling.
5. If there is any impairment of vital functions, such as problems with respiration, airway, circulation, heart function, these must be supported as a priority. In particular, for bites causing flaccid paralysis, including respiratory paralysis, both airway and respiration may be impaired, requiring urgent and prolonged treatment, which may include the mouth to mask (mouth to mouth) technique of expired air transfer. Seek urgent medical attention.
6. Do not use Tourniquets, cut, suck or scarify the wound or apply chemicals or electric shock.
7. Avoid peroral intake, absolutely no alcohol. No sedatives outside hospital. If there will be considerable delay before reaching medical aid, measured in several hours to days, then give clear fluids by mouth to prevent dehydration.
8. If the offending snake has been killed it should be brought with the patient for identification (only relevant in areas where there are more than one naturally occurring venomous snake species), but be careful to avoid touching the head, as even a dead snake can envenom. No attempt should be made to pursue the snake into the undergrowth as this will risk further bites.
9. The snakebite victim should be transported as quickly and as passively as possible to the nearest place where they can be seen by a medically-trained person (health station, dispensary, clinic or hospital). The bitten limb must not be exercised as muscular contraction will promote systemic absorption of venom. If no motor vehicle or boat is available, the patient can be carried on a stretcher or hurdle, on the pillion or crossbar of a bicycle or on someone's back.
10. Most traditional, and many of the more recently fashionable, first aid measures are useless and potentially dangerous. These include local cauterization, incision, excision, amputation, suction by mouth, vacuum pump or syringe, combined incision and suction ("venom-ex" apparatus), injection or instillation of compounds such as potassium permanganate, phenol (carbolic soap) and trypsin, application of electric shocks or ice (cryotherapy), use of traditional herbal, folk and other remedies including the ingestion of emetic plant products and parts of the snake, multiple incisions, tattooing and so on.
Treatment Summary
Bites by this species are not expected to cause medically significant effects and the only risk, probably small, is local secondary infection. Patients presenting with bites by these snakes do not require medical attention, other than to check for infection and ensure tetanus immune status. Patients should be advised to return if local symptoms develop, suggesting secondary infection.
Key Diagnostic Features
Either no effects or minimal local pain & swelling only. No systemic effects.
General Approach to Management
While most cases will be minor, not requiring admission, some cases will be more severe, requiring admission and treatment, so assess carefully before early discharge.
Antivenom Therapy
No antivenom available
No Antivenoms
No images
Find a Reference
Reference Number: