Fer-de-Lance

Responsible for most snakebite fatalities in Central America. Aggressive and fast.

Also Known AsTerciopelo

FamilyViperidae

GenusBothrops

RegionNorth America, South AmericaCentral America, Northern South America

Misidentification risk

Fer-de-LanceCantil

Photo: thibaudaronson · Source: Wikimedia Commons · License: CC BY-SA 4.0

Fer-de-Lance

Photo: thibaudaronson · Source: Wikimedia Commons · License: CC BY-SA 4.0

Fer-de-Lance

Danger Score

Final Danger Score

Venom Core

Lethality weighted 55% (potency × yield). Clinical weighted 45% (real-world CFR).

0.55 × 47 + 0.45 × 6354.2

Modifiers

Multiplicative scalers - amplify or reduce existing danger, can't create it from nothing.

× Speed (1.08)58.5

× Delivery (1.00)58.5

× Encounter (1.04)60.9

Speed = antivenom window. Delivery = fang efficiency. Encounter = exposure × temperament.

Score61

Venom Profile

Type

HemotoxicTargets blood and circulatory system; disrupts clotting and can cause bleeding disorders.,CytotoxicDestroys cells and damages tissue; can cause permanent tissue damage and disfigurement.,MyotoxicDamages muscle tissue, causing myonecrosis (muscle death) and contributing to long-term morbidity.

Venom Yield

High

Venom Speed

Extremely quick

Delivery Method

Hinged front fangs

Potency (SC Equivalent)

8.400mg/kg LD50

Max Dry Yield

250mg dry

Clinical Severity

Fatality (Untreated)

7-15%

WHO Importance

Cat. 1

Local Effects

Pain at bite site, Swelling, Necrosis

Blood

Internal bleeding, Coagulopathy, Circulatory shock

Causes of Death

Massive internal bleeding, Circulatory shock