Coral de Camila
Micrurus camilae

To date, the profile of toxic activity or envenomation symptoms associated to the bite of Micrurus camilae have not been described. Envenoming caused by species of the genus Micrurus are known from a global symptomatic trend, given that venom of this genus have an ancestral trait that allows the presentation of clinical manifestations to be guided along a neurotoxic line. This has facilitated the collection of epidemiological information from Colombia's public health surveillance system (SIVIGILA Spanish acronym), but does not yet allow a specific grouping symptoms by species [1].

Symptoms relies directly on envenoming severity. Records of coralsnake bites reported symptoms that range from anxiety, pain and inflammation to respiratory paralysis. Micrurus venoms causes neurotoxic signs. Local symptoms occur with tingling in the bitten area, paralysis, burning or prickling sensation (paresthesia), mild itching, muscle tenderness and numbness. Paresthesia in large areas of the body appear in moderate and severe cases. Direct neurological symptoms are fuzzy vision, difficulty in speaking, disorientation, confusion, shortness of breath (dyspnea), excessive sweating (diaphoresis), weakness, and even vomit. Several symptoms are related with losing complete limbs sensitivity, difficulty for walk and breath [1,2]. 

Due to the neurotoxic action of the coral snake’s venom and the variation of appearance of symptoms, all M. camilae envenoming must be taken as a serious accident, and medical attention must be carried out immediately to avoid serious lesions or death of the patient [4].

Coral snake bites present high probability of respiratory failure in envenoming and quick medical procedures are important for treatment for the survival of the patient. Firstly, the patient should remain at rest within their possibilities and monitoring should be constant in order to attend any symptom related with respiration [1]. According to the clinical and paraclinical manifestations, the snakebite accident must be categorized as: mild, moderate and severe envenomation (see Envenomation symptoms section).

For envenomation’s caused by any Micrurus species there is a general management protocol depending on the used serum and envenomation level. The first step is to make sure that a Mircurus spp envenomation has occurred by observing the patient symptoms and bites marks in the area bitten. Second, the application of initial doses are 5 to 10 evaluating both allergic and neurotoxicity reactions. Preparation of serums is based on the manufacturer’s specific instructions. However, it is recommended to initiate treatment with 5 vials (INS antivenom) for mild cases and 10 vials (INS antivenom) for moderate to severe cases [1,6]. The dosage is the same for both children and adults [8]. Particularly, for antivenom from Instituto Clodomio Picado, the initial doses are 10 for moderate to severe cases on Micrurus dumerilii; nevertheless, there is a lack of effectiveness in Micrurus mipartitus. Applications of doses are repeated if symptoms persist. The serum is applied intravenously, diluted in 250 ml of saline solution for adults and 100 ml in children over one hour in slow drip dosification. In case of hypersensitivity and anaphylaxis reactions, serum administration might be suspended, treat adverse symptoms and restart at lower infusion rate [1,2].

The genus Micrurus possesses small, grooved, and permanently fixed fangs attached to the anterior section of the maxillary bones (proteroglyphous, see Chapters 2 and 5). Despite their potent neurotoxic venom, their narrow gape (≤30°) and small fangs result in a low biting capacity, which represents a low risk of envenomation for people wearing clothing, boots, or protective gear. Most bites typically occur on the hands during intentional or unintentional handling or capture.

Unlike viper snakes (family Viperidae), fang marks may or may not be evident. When visible, they resemble small puncture wounds, appearing as two dots—one from each fang—typically spaced 0.5 to 2 cm apart. Therefore, even in the absence of visible marks, Micrurus specimens sometimes exhibit chewing behavior and remain attached to the bitten area. However, the defensive behaviors of M. camilae are unknown and poorly explored. Thus, these events should not be underestimated, as any accident carries the risk of venom inoculation [1–3].

In Colombia, there are no specific epidemiological records for M. camilae. Nevertheless, it is likely that this species has caused bite incidents within its known distribution range. However, due to the limited capacity of the SIVIGILA system to determine the causative species of an accident, these cases are likely part of the national underreporting [1,2] (see Chapter 9).

Micrurus camilae is a coral species with bicolor coloration (alternated color) of black and pale yellowish in the ventral surfaces and a dorsal banded of red along the dorsal surfaces of the body. The black coloration of head goes from the rostral through the supraocular, including the medium part of the frontal scale and the anterior edge of parietal scales; laterally the black band includes from first to the fourth supralabial scales and the posocular scales. Ventrally, the black color covers the mental, first and second infralabial scales contrasting with the pale yellowish color of the rest of the ventral surfaces of the body. The red covers the extreme frontal scale getting less noticeable until labial scales. The red areas extend only throughout the dorsal surfaces of the body and tail. The whole body (including body and tail) have a total of 31 black rings (4 to 8 scales of width) and 30 red / pale yellow rings (5 to 7 scales of width) [3–5]. There is not similar coral snake with this color pattern in Colombia. However, M. camilae could be confused with Micrurus mipartitus, and can be distinguished by the afforementioned pale yellowish rings interrupted by red in dorsal along all body. Micrurus mopartitus present anomalus coloration but never as M. camilae, in addition, Micrurus mipartitus present red tail bands [3–6].

Micrurus camilae is an endemic snake species of Colombia, distributed in the Urabá and Middle Magdalena Valley regions, within the Magdalena-Urabá moist forest ecoregion. It has been reported at elevations between 88 and 176 meters above sea level in environments characterized by high anthropogenic activity, fragmented forests, and stream edges [3,6–8], with an estimated extent of occurrence of approximately 44,971 km².

Figure 1. Geographic distribution of Micrurus camilae in Colombia and its habitat suitability model. Based on bioclimatic variables, the habitat suitability model predicts the species' potential distribution in Colombia, identifying zones with suitable or unsuitable environmental conditions for its occurrence across the country. Values close to 1 indicate optimal environmental conditions (high probability of presence), while values close to 0 indicate unsuitable conditions (absence likely).

The scientific name is derived from the Greek roots mikros (small) and oura (tail), in reference to their short tails, which is a general trait of species within the genus Micrurus. The species Micrurus camilae was dedicated to María Camila Renjifo, the daughter of Juan Manuel Renjifo, the lead author of the publication that describes the species [5].

Table 1. Summary of important biological, venomic, epidemiological and medical traits.

★ Poorly Reliable: Confidence for this species is poor due to the lack of data and information on Colombian populations. Therefore, most of our knowledge comes from a few studies and populations outside the national territory. LD50: median lethal dose; MCD: minimum coagulant dose; MDD: minimum defibrinating dose; DEM: minimum edema-forming dose; DHM: minimum hemolytic dose; PLA2: phospholipases A2; SVSP: serine proteases, SVMP: metalloproteinases; NGF: nerve growth factor; CRISP: cysteine-rich secretory protein; CTL: C-type lectin/lectin-like, DIS: disintegrins, KUN: Kunitz peptides; BPPs: bradykinin-potentiating peptides; VEFG: vascular endothelial growth factor; 3FTx: three-finger toxins; LAAO: L-amino acid oxidases.