Oversized fangs in
Australian elapids - the consequences.
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Doncaster, Victoria, 3108, Australia
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Originally Published in Monitor – Journal of
Victorian Herpetological Society, 16(1)(June 2007):6-9. Reprinted in Herptile - Journal of the International Herpetological Society 32(3)(September 2007):112-115
This paper reports on oversized fangs in five very
different species of Australian elapid snake, namely Taipans (Oxyuranus scutellatus), Tiger Snakes (Notechis scutatus), Red-bellied Black
Snake (Pseudechis porphyriacus),
Desert Death Adder (Acanthophis pyrrhus)
and Golden-Crowned Snakes (Cacophis
squamulosus). Oversized is defined
here as fangs penetrating though the lower jaw of the snake at the time the
mouth is closed. Unlike other venomous
snakes, the fangs of elapids are essentially fixed and immobile and hence if
over-sized must penetrate through the flesh of the lower jaw.
Adverse consequences of oversized fangs in live snakes
include making sloughing more difficult and the added provision of anchor
points for parasitic ticks and mites in and around the lesions that form where
the snakes penetrate the lower jaw.
Both have been observed in captive and wild snakes
where fangs penetrate the lower jaw.
The first published photo of an elapid with fang
penetrating through the lower jaw was in Hoser (1989). That snake, an adult Golden-crowned Snake (Cacaphis squamulosus) was thought to be
unusual, but in the decade following, at least two more similar specimens have
been seen by myself (all from West Head/Cottage Point, NSW).
The same trait has been seen in adult Taipans (Oxyuranus scutellatus) by myself (see photo to right - snake with lighter snout and tongue out) and
reported on the internet by other herpetologists, the latter not including
specimens sighted by myself.
The same trait has also been seen in some very large
Tiger Snakes (Notechis scutatus), all
from Melbourne. What follows is an
appraisal of what's been observed in these and other elapid taxa by myself to
The cases involving this species have involved
wild-caught adults. There is no available
information in terms of when this fang-penetration manifested in the snakes
(see below) or any adverse health consequences as a result of the fang
While the first photo of this was published in Hoser
(1989) in an adult C. squamulosus,
interest in this event was minor until observed in Taipans.
Taipans are medically significant snakes in that any
envenomation may be fatal to humans (Hoser 2002a). Hence the prospect of having an effective fang penetration of
human skin by a snake with a closed mouth is noteworthy, bearing in mind that
people often hold these snakes by the head and with the mouth forced shut.
In 2004 I observed two adult Taipans (male 210 cm
total length, female 180 cm total length), both from Proserpine Queensland.
Both were seen to have lesions under the lower jaw and
both had large ticks (species unknown) lodged in them. At the time the ticks were removed, it was
noticed that the lesions had been formed by the fangs penetrating the lower
jaw. The snakes had been in captivity
for some time, but in an outdoor pen, explaining the ability of the ticks to
move onto the snakes.
One of the Taipans laid 9 eggs on 2-4 December 2004,
which hatched on 16 Feb (2 eggs) and 19 Feb (2 eggs). The eggs were incubated at 30°C and the other five were apparently infertile. No neonate Taipans had
fangs penetrating the lower jaws. None
developed such a condition in the two and a half years following hatching.
The relative size of fangs in this species is large by
Australian standards and this is not widely known, or reported in the
Other notes of relevance in terms of Taipan Fangs
(with general reference to the taxa “O. scutellatus” as opposed to “O.
microlepidota”, unless otherwise noted) follows.
The literature reports that the striking nature of
this snake is “snap and release”, see for example Barnett (1999), his earlier
papers (see sources within Barnett 1999) and papers that refer to
Barnett’s. Barnett’s statement to this
effect is also based on direct experience of the captive snakes referred to in
his paper (beyond about a month of age).
However my own experience of this taxa involving
different specimens indicates that they prefer to hang onto their prey items
(rodents) after biting them.
While it could be argued that either situation may be
“normal” my view is that the Barnett snakes are the aberrant ones in terms of
the wild state, notwithstanding that most reports on wild snakes have them
striking and releasing items.
Wild snakes as a rule are seen striking at humans and
hence their strike release bites can be seen as defensive as opposed to
Furthermore the size of the fangs (almost sabre-like)
indicates that they are designed to hold onto the prey. This is different to other snap-release
snakes with much smaller fangs, including for example the Brown snakes (Pseudonaja).
Taipans held by myself typically strike at their prey
and then pull them under cover whereupon the food is eaten.
While this is true for both the Coastal Taipan (Oxyuranus
scutellatus) and the Inland Taipan (Oxyuranus microlepidota), the
trend is strongest in the Coastal Taipan which also has pro-rata far larger
Fang penetration of lower jaw in this species has been
well-studied by myself.
Around late 2003 and early 2004, I acquired 10 mainly
young Tiger Snakes (Notechis scutatus)
from the Melbourne region, (Victoria, Australia).
When acquired, no snakes had any evidence of fangs
penetrating the lower jaw. However as
snakes matured, this trait became evident in some snakes. The snakes most affected were generally the
largest and most heavily built (over 120 cm total length).
When the fangs began to penetrate the lower jaws,
lesions would form around the puncture marks.
These wounds would scab up and over several months would alternate
between being apparently healed pockmarks and slightly festering wounds.
As a rule, the condition eventually settled down
without treatment to become a healed pair of holes in the lower jaw, through
which the fangs permanently penetrated.
While the snakes never showed any apparent concern for
their condition, one drawback did become evident.
At the time sloughing was due, affected snakes
sometimes were unable to shed the skin on their lower jaw. In some cases this
lower jaw skin was retained, while the snake otherwise shed without
problem. But in other cases this
"blockage" in the shedding process stopped the process continuing,
the result being the snake was unable to slough at all.
The blockage was caused by skin sticking in the region
of the lesion and failing to peel off, hence preventing the normal sloughing
process proceeding beyond this point.
Those snakes were dealt with quite easily by soaking
in luke warm water (about 30°C) until the skin covering the body
was sufficiently loose to either flake off or be easily manually shed by myself
(by simply using my hands to gently rub or peel off the skin).
Notable is that fang penetration of the lower jaw
seems to be relatively uncommon in wild Tiger Snakes (which I see large numbers
of through my "controller" catch-release permit), but relatively
common in captive snakes.
Red-bellied Black Snake
One (then immature) male Red-bellied Black Snake
acquired at end 2003 measuring 60 cm had no evidence of fang penetration of the
lower jaw. By May 2005, the snake
measured nearly 150 cm and had fangs penetrating the lower jaw. On at least one occasion this snake was
unable to slough due to an inability to remove skin from the lower jaw,
stopping the process from continuing.
The snake's slough was removed using the process described above.
Desert Death Adder
I have never observed fangs penetrating the lower jaw
of any Acanthophis species, with the
exception of a single adult male Desert Death Adder (A. pyrrhus) from Goldsworthy, Western Australia. This is noteworthy as I have inspected
hundreds of specimens from all 15 described taxa from Australia and islands
north of Australia (taxonomy of Hoser 2002b).
Fang penetration is seen on specimens ranging up from half
grown. Notwithstanding the fact that it
is reasonably common in the taxa around Melbourne (my crude estimate is about 1
10 adults), I have never seen it to a degree that is so obviously noticed as
for example seen in Tiger Snakes.
In terms of snakes kept by myself, I am very proactive
in terms of sloughing difficulties.
Snakes are not left alone beyond the timing of
non-sloughing, if it is evident that the snake should have sloughed. Snakes with any retained skin are soaked
until the skin either flakes off, or is easily removed by myself. This is due to the fact that beyond the
correct sloughing time, retained skin dries, becomes harder to remove and can
encase the snake like a straight jacket.
If too much skin is retained to long, the condition may cause stress or
The preceding is mentioned only in as much as to make
the point that some snakes that retained skin in the captive situation at my
facility may in fact have shed if they had been left.
Also the husbandry regime employed by myself may have
also been suboptimal in terms of sloughing of snakes. This regime included bone dry cages, lined with newspaper which
provide various health benefits, but not necessarily pre-slough, and perhaps
more importantly frequent handling pre-slough during live reptile shows. This preslough handling does cause more
emaciation of the snake and drying of the skin than would otherwise occur if
the snake was left sitting in a cage.
The surface emaciation process is also sometimes
accelerated by feeding pre-slough snakes.
This is generally not advised for captive snakes, but
is routinely done here, due mainly to the fact that snakes are fed between
snake shows at times that allow for maximum time to digest food between shows
Having said this, it is an inescapable conclusion that
the sloughing problems seen at my facility in snakes with fangs penetrating the
lower jaw would also occur in wild snakes with oversized fangs.
The other issue of ticks (or mites if present) seizing
on the lesions to lodge is obviously something that would be seen in wild
snakes and hamper sloughing in wild snakes.
It is also clear that the tendency of fangs to
penetrate the lower jaw is increased in large adult snakes of a given species.
While it appears to be most commonly seen in Tiger
Snakes and Taipans of the Australian elapids, this trend may merely reflect the
amount of observation by myself and others.
It is likely that fang penetration of lower jaws is
common in many large elapid species. In
terms of small elapids, I am of the view that the trait is probably less
common, but still occurs.
Notable is that while Death Adders (Acanthophis) pro-rata have the largest
fangs of the Australasian elapids, fang penetration of the lower jaw in these
snakes is not as common as seen in other taxa such as Notechis and Oxyuranus.
In other words, the physical dynamics of head shape
also have a bearing on the likelihood of fang penetration of the lower jaw.
Large fangs are essential to Acanthophis species that tend to hang onto their prey. Large fangs are not as important for
"snap-release" species or "Chew when feeding" species like
Tiger Snakes. The Inland Taipan also
appears to “Chew” when it bites prey (or people), as opposed to (my) Coastal
Taipans that hang onto their prey and then pull back. These differences may have given rise to a noticeably smaller
fang size (relative) in the Inland Taipans.
However this may not be the full picture as evidenced
by an apparently undeniable trend for the elapid snakes to develop fangs as large
as their mouth will accommodate (or even larger).
Noting the physical limitations of elapid snakes in
terms of their relatively fixed to bone fangs and flesh on the lower jaw, there
appears to be an evolutionary equilibrium point where fangs may be allowed to
penetrate the lower jaw. The
equilibrium point is presumably where the advantages of the slightly larger
fangs are outweighed by the disadvantages caused by the permanent lesions on
the lower jaw surface. The
disadvantages may include infection risks that are not treatable for wild
A final point of note that is that larger snakes and
those in better physical condition appear to have relatively larger and better
developed venom apparatus in the form of venom glands and fangs. This trend has been noted when doing
venomoid surgery on snakes.
The trend also appears to manifest in terms of the
greater apparent frequency of large captive snakes having fangs penetrating the
lower jaws, when compared to wild snakes.
There is therefore a possibility that fang penetration
of lower jaw may be more common in overfed captive snakes than their wild
counterparts. This theory could be
easily tested with a series of controlled experiments.
Reptiles subject of this paper were supplied by several
individuals in several states over many years and under permits issued by the
relevant authorities. All are thanked.
1999. Keeping and Breeding the Coastal Taipan (Oxyuranus scutellatus). Monitor
– Journal of the Victorian Herpetological Society 10 (2/3):38-45.
Hoser, R. T.
1989. Australian Reptiles and Frogs.
Pierson and Co., Sydney, NSW, Australia. 238 pp.
Hoser, R. T.
2002a. A review of the Taipans Genus Oxyuranus
(Serpentes:Elapidae), including the description of a new subspecies. Crocodilian 3(1):43-50.
Hoser, R. T.
2002b. Death Adders (Genus Acanthophis):
An Updated overview, including descriptions of 3 New Island species and 2 New
Australian subspecies. Crocodilian
4(1): 5-11,16-22,24-30, front and back covers.