Western hognose snake

[Ceratodromeus]

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Subfamily: Xenodontinae
Genus: Heterodon
Species: H. nasicus


Description
This snake is described as being "stout bodied" and doesn't grow to considerable lengths. Males rarely,if ever exceed 18 inches in length. Females are much larger; Sexual dimorphism in overall body size is present in Heterodon, following the typical
pattern for colubroid snakes lacking male-male combat (Shine 1993), with the largest
females being up to 230% larger than the largest males (Ernst & Ernst 2003). However, females reach sexual maturity at a later age. H. nasicus get its name from the modified rostral scales that are formed in an upturned manner, providing a very "swine like" appearance. This modified rostral scale aids in burrowing when the snake is trying to get out of the elements.


Dietary habits: Western hognose snakes predominately feed on amphibians, notably small species of tree frogs(Hyla )but they are known to take lizards, and mice. Though the latter is not common place, and there are few documents of it occuring. Captive bred individuals are even known to take gold fish when offered.
Documents on the diet of the western hognose propose a more toad oriented diet then anything else.{1} Juveniles are limited in what they can take, but as body size grows, the variety of prey they can take does as well. As primarily Bufophagous, these snakes display an innate tolerance to bufotoxins.


Venom:

There is some debate on how potent H. nasicus venom truly is. They are Opisthoglyphs(rear-fanged) and they rarely, if ever, bite in defense. However, effects noted after a hognose bite include swelling, blistering, and the skin becomes "hot"to the touch.{2}, {3}
An example of such envenomation



Predators & Death feining:
Documented predators of the western hognose include, coyote, crow & hawks (Blair & Schitoskey 1982) But are not limited to them. mammalian mesocarnivores,
predatory birds (e.g., shrikes, corvids, flycatchers, icterids), and other snakes (e.g., Coluber
constrictor, Lampropeltis spp.). Juvenile hog-nosed snakes may fall prey to rodents, shrews,
moles or other small mammals, or to large spiders (Edgren 1955), Invasive fire ants (Solenopsis spp.){1} also pose a threat not only to juveniles, but to adults as well.These particular snakes are known to "fake death" when confronted by a predator. Such tactics trick the aforementioned predator into thinking the snake is no longer worth a meal, and while the predator is looking in another direction, the snake opts to flee. If escaping is no longer an option, the snake laterally compresses its neck, flaring ribs in an attempt to make it appear larger. In some instances, blood hemorrhages have been noted when H. Nasicus participates in "feigning death"
Below is an example of such behavior


References
1. Durso, Andrew Michael. "Interactions of diet and behavior in a death-feigning snake (Heterodon nasicus)." (2011).
2. Morris, Michael A. "Envenomation from the bite of Heterodon nasicus (Serpentes: Colubridae)." Herpetologica (1985): 361-363.
3. Weinstein, Scott A., and Daniel E. Keyler. "Local envenoming by the Western hognose snake (Heterodon nasicus): A case report and review of medically significant Heterodon bites." Toxicon 54.3 (2009): 354-360.

[Ceratodromeus]

Report of envenomation on a 21 year old woman:



"A 21-year-old female presented to an emergency

department approximately 3–4 h after sustaining a bite on

the left anticubital fossa from a captive young adult

(approximately 45 cm, total length) Western hognose

snake, H. nasicus. The patient had no prior history of Heterodon

bites. The snake was a long-term captive in

a university biology department collection, and she was

bitten while feeding the snake a small mouse. She reported

that the snake maintained a grip on the arm for approximately

3–5 min and had to be removed by manual force

(the jaws were pried open by forcible lifting of the maxilla

via the snout). The resulting punctures bled freely for

several minutes following the bite. During the first 3 h

following the bite, she experienced no appreciable pain or

swelling. She later reported that the swelling noticeably

increased several hours after the bite, and thus sought local

medical attention. Tetanus immune status was confirmed

and 1.0 g of ceftriaxone, i.v. was administered. Edema of the

left arm increased and expanded and, due to concerns of

medical personnel unfamiliar with snakebites, the patient

was transferred to a Level I trauma center. Upon arrival,

toxicology consultation was obtained. Approximately 5 h

after the incident, noted was edema involving the left

elbow extending to the wrist, mild ecchymosis and two

clearly defined punctures proximal to the anticubital fossa.

The patient’s laboratory results (including complete blood

profile, comprehensive metabolic profile and basic coagulation

tests) all were within normal limits on presentation.

She complained of mild pain associated with the increased

tension of the edema. . Following admission, she remained

stable and all laboratory tests remained unremarkable. On

examination 24 h after the bite, the patient’s left arm

exhibited marked edema and lymphadenopathy). At 48 h, blister formation both distal and

proximal to the bite involving the left anticubital fossa and

lateral–ventral wrist was observed). The

patient was discharged with a prescribed regimen of

diphenhydramine. Shortly after discharge (approximately

30 h after the bite), she followed-up with her primary care

physician and aspirate was obtained from several blisters

and sent for culture/sensitivity. This aspirate remained

culture negative. The patient received local wound care,

amoxicillin/clavulanate (875 mg, p.o., twice per day) was

prescribed and desloratidine was substituted for the

diphenhydramine. Acetominophen/hydrocodone (500/

5 mg) as needed was prescribed due to left arm pain

encountered during positioning for sleep. She also noted

stiffness in her left wrist and digits. The blisters drained

quantities of serous discharge that required regular

multiple changes of wound dressings. Review at 72 h postbite

showed reduced edema, ecchymosis and an increased

zone of erythema suggestive of cellulitis). At 96 h post-envenoming, noted were persistent

edema of the left hand, ecchymosis and blistering of the

medial-ventral left arm Twenty-eight

days after the incident, the patient reported pruritis of the

left forearm with reduced ecchymoses and resolving blisters.

The edema, pruritis and stiffness improved during the

following two weeks. At ten weeks post-envenoming,

multiple milia were observed at the wound site, most

notably at the wound margin. Healing was complete at five

months."

Taken from: Weinstein, Scott A., and Daniel E. Keyler. "Local envenoming by the Western hognose snake (Heterodon nasicus): A case report and review of medically significant Heterodon bites." Toxicon 54.3 (2009): 354-360.

[Ceratodromeus]

A novel prey item(Documented in the December issue of the herpetological review)

[Venomous Dragon]

A very interesting little snake.