Generales

A newly discovered species of tarantula that lives near Medellín has been described by researchers from Universidad de Antioquia.

Researchers from Universidad de Antioquia have discovered a new species of tarantula near the city of Medellín, Colombia. The spider has been named Aguapanela Arví, after a nature reserve located near Medellín where it was discovered. Researchers seek to debunk common myths about these beautiful spiders which are not nearly as dangerous to humans as believed.

The new tarantula  has been described by researchers at the UdeA School of Pharmaceutical and Food Sciences

Tarantulas have robust bodies covered with dense, urticating hairs that cause severe irritation after coming into contact with the skin of an attacker. When threatened or disturbed, they assume defensive postures by raising the front legs like a prancing pony and showing its venom-dripping fangs (which are actually oral appendages called chelicerae).

This never-before-seen breed of tarantula inhabits the wooded area of Parque Arví, a nature reserve on the outskirts of Medellín. Researchers Sebastián Estrada, Yeimi Cifuentes and Carlos Perafán named the spider Aguapanela Arví, after both a popular Colombian drink known as aguapanela and its place of discovery.     

“The UdeA Serpentarium is home to a type of tarantula which has very different characteristics than those of the species we know”, says Professor Estrada. “Along with Professor Yeimi Cifuentes and Professor Carlos Perafán - who are perhaps the leading experts on tarantulas in Colombia - we gave ourselves the task of collecting more specimens in order to make a more detailed analysis of their characteristics,” he said.

A comprehensive study using a scanning electron microscope (SEM) was needed to determine whether this species has not already been described. Such a complex task was conducted by the skilled UdeA SEM operator Dayana Meza. 

Likely a new genus, researchers say

Several morphological characteristics (physical shape and appearance) suggest that the newly discovered spider has not been described before.  “We found some significant differences in the palpal bulb of males, the female’s spermathecae, and the setae (urticating hairs) on the abdominal zone and the legs,” Professor Estrada said.

There are also some behavioral differences such as the unusual defensive and attack positions. “Unlike other tarantula species, the Aguapanela Arví lies down on the belly while lifting the front legs to attack or defend itself from predators,” says Estrada.

These clues led the researchers to conclude that the spider is part of a new genus of Theraphosidae (scientific name of tarantulas). Several specimens of this species have been found prowling the cold forests of Santa Elena, a small town near Medellín where Parque Arví is located.

Scary, but not that dangerous

Despite their fearsome appearance, so far there have been no verified reports of human deaths caused by tarantula bites. However, many people continue to fear tarantulas due largely to films and the bad reputation they have. 

In the wild, tarantulas primarily eat insects, though some species also eat frogs, toads and small rodents.  But Aguapanela Arví differs from other species “as it is more aggressive than other types of tarantulas, nevertheless, further studies are needed in order to determine the toxicity of its venom,” Estrada said.

There are also other behavioral characteristics that are unique to this species.

"Most tarantulas are nocturnal hunters. While males emerge from their burrows at sunset in search of mates, female tarantulas tend to stay in their homes. But oddly enough, female Aguapanelas also leave their burrows", the researcher said. 

The researchers said that the spider was named in honor of a popular Colombian drink called aguapanela, which is typical of the eastern highlands of Medellín where the spider was discovered.  “Researchers across the world seem surprised by the fact that such a species exists at altitudes between 2200-2400 meters above sea level,” Estrada said.

The researchers believe that this species is endemic to this part of Antioquia. It is such an exciting experience when new species turn up unexpectedly close to home, therefore, describing previously undescribed species such as this is essential to better understand the diversity and ecological importance of Parque Arví or “land of plenty”, as our ancestors called it.