Snakes capable of expelling venom are a fascinating group, utilizing a specialized defense mechanism distinct from typical venom injection through a bite. This unique behavior, known as spitting, serves primarily as a deterrent against perceived threats rather than for subduing prey.
Snakes Known for Spitting
The majority of snakes known for spitting venom belong to various species of cobras, found across both Africa and Asia. African spitting cobras include species such as the Black-necked Spitting Cobra (Naja nigricollis), widely distributed in sub-Saharan Africa, the Mozambique Spitting Cobra (Naja mossambica) prevalent in southern and southeastern Africa, and the Red Spitting Cobra (Naja pallida) found in East Africa. In Asia, examples include the Indochinese Spitting Cobra (Naja siamensis) from Southeast Asia, and the Philippine Cobra (Naja philippinensis) and Samar Cobra (Naja samarensis) from the Philippines.
Beyond the true cobras (genus Naja), another prominent spitting snake is the Ringhals (Hemachatus haemachatus), indigenous to Southern Africa. While it shares the spitting ability and can spread a hood like a cobra, the Ringhals is not classified within the Naja genus due to distinct morphological differences. This convergent evolution of spitting ability across different lineages highlights its effectiveness as a defensive strategy.
How Spitting Works
Spitting snakes possess unique physiological adaptations that enable them to expel venom as a directed spray. Unlike other venomous snakes, their fangs feature modified, forward-facing orifices rather than openings solely designed for injection. When threatened, these snakes contract powerful muscles surrounding their venom glands, which forcefully eject the venom through these specialized fang openings. This process creates a fine stream or mist of venom that can travel up to 3 meters (10 feet) with considerable accuracy.
The snakes aim for the eyes of a perceived threat, often employing rapid head movements from side to side to increase the likelihood of hitting the target. This action is purely defensive, designed to deter attackers by causing immediate discomfort and temporary incapacitation. While these snakes can still deliver a venomous bite, spitting is their primary defensive action in many encounters.
Effects of Spat Venom
When venom comes into contact with the eyes, the effects are immediate and intense. Individuals experience severe pain, a burning sensation, and involuntary eyelid spasms. The venom causes inflammation of the eye’s anterior segment, leading to symptoms such as redness, swelling, and corneal damage. Temporary blindness is a common outcome, and without prompt treatment, prolonged exposure can result in more serious issues like corneal ulcers, permanent tissue damage, or even lasting vision impairment.
On intact skin, spat venom causes less severe reactions, often limited to irritation or redness. However, if the venom encounters open cuts, abrasions, or mucous membranes, it can be absorbed, potentially leading to a localized cytotoxic effect or, rarely, systemic symptoms. Spitting cobra venom contains cytotoxins that cause cell destruction, contributing to intense pain and tissue damage, particularly in ocular exposures.
Safety and Emergency Steps
Encountering a spitting snake necessitates immediate and appropriate action to minimize harm. If venom enters the eyes, the most important first aid step is to flush them immediately and copiously with any available bland liquid, such as water or saline. This rinsing should continue for at least 15 to 20 minutes to wash away as much venom as possible. Prompt medical attention is crucial following rinsing, as a healthcare professional can assess for corneal damage and prescribe necessary treatments like antibiotic or anti-inflammatory eye drops.
To prevent such incidents, particularly in areas where spitting snakes are present, maintaining a safe distance from any snake is advisable. Wearing protective eyewear, like glasses or goggles, can offer a barrier against venom spray. Additionally, general precautions such as clearing debris around living areas and being aware of surroundings can reduce the likelihood of unexpected encounters.