Introduction to Acanthophis rugosus

This time, we only keep 4 baby´s at our facility.

Description: Short, thickset snakes with large angular heads and raised supraocular scales that give the appearance of small horns. The tail is thin and ends in a soft ‘spine-like’ tip. Colour varies enormously and background body colour can vary from almost black to red, brown, yellow or light grey interspersed with alternate light and dark transverse bands which are most prominent when the snake is threatened. Smooth-scaled death adders (Acanthophis laevis) usually have a rather subdued pattern, whereas most rough-scaled death adders (A. rugosus) are very contrastingly patterned. The labial scales are usually white with dark brown or black streaks. The belly is white with darker spots.

Scalation: Dorsal scales in 21-23 rows at mid-body; 110-135 ventrals; anal single; 36-60 subcau dals – anteriorly single, paired posteriorly. The dorsal scales of A. laevis are usually smooth or weakly keeled, while those of A. rugosus are strongly keeled and look rough, particularly on the neck.

Body Size: Average length approximately 50 cm, maximum 90-100 cm. Females longer than males. There are reports of dwarfed populations in the Highlands and unusually large specimens in river valleys in northern PNG, but in the latter case, specimens are lacking, and it is likely that large ground boas (Candoia aspera) are being mistaken for death adders.

Distribution: Smooth-scaled death adders (A. laevis) occur in all of the mainland PNG provinces and on closer islands such as Karkar, Yule, Daru and those in the mouth of the Fly River. It is also found throughout West Papua and on Seram and the Aru islands. The rough-scaled death adder (A. rugosus) is currently only known from south-eastern West Papua (Merauke region), but probably also occurs in the south-west corner of the South Fly District around Weam and Morehead.

Habitat: Death adders occur in a wide range of habitats including lowland grasslands and savannahs, sago swamps, monsoonal forests, woodlands, rainforest, coffee, tea and cocoa plantations, village gardens, highland grasslands and other montane environments. These ground dwelling snakes can be common in any area with abundant leaf litter, grass trash or other ground cover in which they can hide. They often occur around forest margins, or on the periphery of garden plots, and near the sides of walking tracks: all areas of filtered sunlight and abundant lizard prey.

Diet: Predominantly small ground-dwelling lizards, frogs and occasionally small rodents or ground birds that are attracted to wriggling of the snake’s grub-like tail. The tail does not contain a poisonous sting.

Reproduction: One of the very few venomous snakes in PNG which produce live-born young in litters of 8-12. Juveniles range from 0.17-0.24 metre at birth.

Activity: Generally nocturnal, these snakes usually sit under cover during the day, often close to pathways along which small animals (and people) regularly travel. If disturbed (by the burning of grass for example) they may move around during the day. Often seen crossing roads and paths at night, especially at dusk when people are returning home from the garden or bush. Although this represents one danger period for contact with this snake, many bites occur in daytime when people step on the sleeping snake, or touch it as they reach down to pick up something.

Behaviour: Death adders are unique among PNG snakes in their reliance on a ‘sit and wait’ ambush feeding strategy, which means that they will remain motionless on the ground even when approached very closely. These inoffensive snakes become a significant snakebite threat because of this behaviour. While most snakes will flee from an approaching human, death adders rely on remaining motionless to avoid detection, but if touched will strike reflexively.

Medical Importance: Although considered responsible for only about 10% of serious snakebites in Central Province, death adders are the major cause of snakebites throughout much of the rest of PNG, and in particular northern PNG where they are the most commonly encountered venomous snake (Lalloo et al, 1995a, 1996). In Gulf province, death adders are the major cause of envenoming in communities around the Purari, Kikori and Turama Rivers to the west of Kerema (Williams, 2005). Death adders are also the dominant venomous species in most of the forested regions of Western Province, and are the most common cause of snake bites in the Rumginae, Tabubil, Mougulu and Nomad areas.

Venom: Death adder venoms are rich in postsynaptic neurotoxins, as well as a variety of minor components, including weak anticoagulants. Specimens from neighbouring Papua have been found to contain myotoxins in their venoms, but rhabdomyolysis is not common in patients bitten by death adders in PNG, and paralysis is the major clinical effect of envenoming.

Did nobody else here keep Acanthophis?
would love to find more first hand informations about them.


cheers
Mario

Hi Mario,
I have just recieved a rugosus from a friend and I found your article very interesting.
There was a case of rugosus snakebite, here in England earlier this year, there is little information on the symtoms, but the patient did suffer from acute renal failure, something unheard of from Australian Death Adders, so this probably indicates the presence of myotoxins in rugosus.
All the best,
Brian.

Hi Brian , I came across this information from http://cat.inist.fr/?aModele=afficheN&cpsidt=15005180 '' Based on early studies on Acanthophis antarcticus (common death adder) venom, it has long been thought that death adder snake venoms are devoid of myotoxicity. However, a recent clinical study reported rhabdomyolysis in patients following death adder envenomations, in Papua New Guinea, by a species thought to be different to A. antarcticus. Subsequently, a myotoxic phospholipase A2 component was isolated from A. rugosus (Irian Jayan death adder) venom. The present study examined the venoms of A. praelongus (northern), A. pyrrhus (desert), A. hawkei (Barkly Tableland), A. wellsi (black head), A. rugosus, A. sp. Seram and the regional variants of A. antarcticus for in vitro myotoxicity. Venoms (10-50 μg/ml) were examined for myotoxicity using the chick directly (0.1 Hz, 2 ms, supramaximal V) stimulated biventer cervicis nerve-muscle preparation. A significant contracture of skeletal muscle and/or inhibition of direct twitches were considered signs of myotoxicity. This was confirmed by histological examination. All venoms displayed high phospholipase A2 activity. The venoms (10-50 μg/ml) of A. sp. Seram, A. praelongus, A. rugosus, and A. wellsi caused a significant inhibition of direct twitches and an increase in baseline tension compared to the vehicle (n = 4-6; two-way ANOVA, p < 0.05). Furthermore, these venoms caused dose-dependent morphological changes in skeletal muscle. In contrast, the venoms (10-50 μg/ml; n = 3-6) of A. hawkei, A. pyrrhus, and regional variants of A. antarcticus were devoid of myotoxicity. Prior incubation (10 min) of CSL death adder antivenom (5 U/ml) prevented the myotoxicity caused by A. sp. Seram, A. praelongus, A. rugosus, and A. wellsi venoms (50 μg/ml; n = 4-7). In conclusion, clinicians may need to be mindful of possible myotoxicity following envenomations by A. praelongus, A. rugosus, A. sp. Seram, and A. wellsi species.

Hi Andew,
Thank you for that very interesting information, it would be interesting to know if any clinician in Australia has ever seen myotoxicity in confirmed Death Adder envenomation.
All the best,
Brian.

Hello,

Adder on this pictures looks a lot like A.praelongus i had last year, they had a nasty disposition just like i'we heard for Rogosus. Very Nice snakes.

Keep the good work

Do you knowe if any one in europe breed Acanthophis?

Nice snaka what vintertemp shall i keep them ,summer 33 celsius hot spot 25 normal day
nigth 25 .

Mats