What Happened When the Spiny Hands Crab Invaded Colombia?

Although Colombia’s most famous invasive species is the hippopotamus, there is another threat lurking in Caribbean waters: an invasive species of crab.

The Indo-Pacific swimming crab (Charybdis hellerii) has already invaded the west coast of the Atlantic Ocean and a study in Belize found that it may have displaced several native crustacean species from shallow-water habitats.

Alejandro Lozanograduate of marine biology at Universidad Jorge Tadeo Lozano with a master’s degree in marine sciences from Universidad Nacional de Colombia, says the crab was likely introduced to Colombia’s Caribbean coast by commercial ships, possibly from another invasive population in the Mediterranean.

Lozano is first author of the study”Variabilidad fenotípica en la populación de la jaiba invasive Charybdis hellerii (Milne-Edwards, 1867) (Decapoda: Portunidae) en el margen continental del Caribe colombiano” was published in the journal Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales, which according to the authors is the first overview of the situation of this invasive species in Colombian territory and how it was able to adapt to its new home.

“The idea for this article arose because of the limited attention this crab has received in Colombia and the potential impact it could have on the country, as evidenced in other parts of Latin America such as Venezuela and Brazil, where it has directly affected ecosystems and fisheries,” says Lozano.

He explains that this crab has been widely reported: from the upper Guajira to the Gulf of Morrosquillo and in the study the researchers showed that some of the areas the crabs reached were more suitable for them than others.

“Research of this species lays the foundations for a better understanding of its population dynamics in the event of a critical situation, similar to what happens with the red swamp crayfish (Procambarus clarkii) in parts of Cundinamarca and Boyacá,” says Lozano, “I think it’s vital that invasive species studies are taken into account when laws are being legislated for species conservation and management.”

From spiders to crabs

Lozano was born and raised far from the sea, in a Colombian town called Tunja, 2800 meters above sea level in the Andes mountain range.

“Since I was young, I’ve always been interested in animals, especially invertebrates: spiders were my passion before I discovered crustaceans,” he says, adding that questions about the origin of life led him to study molecular biology.

Lozano was then able to work at the Conservation Program for Turtles and Marine Mammals (ProCTMM) at Jorge Tadeo Lozano University and helped conduct genetic studies on loggerhead turtles.

“Research in this part of the world takes on enormous importance when we consider where the greatest sources of diversity and vital resources for humanity are,” he says, “For example, the study we conducted in Colombia is important for the conservation of many ecosystems that provide countless services to communities”.

Lozano says that from his perspective, he can help raise awareness of many issues to help preserve Colombia’s biological heritage.

“I don’t just focus on species classification; I also incorporate the complex interactions within ecosystems,” he says, “By understanding these interactions, we can better understand macro-phenomena.”

Freshwater crabs

Another Colombian scientist working on crab research (but on a native freshwater species) is Juan Mateo Rivera Pérez.

He is a PhD student in ecology at the Federal University of Pará (UFPA) Belém, Brazil, and first author of a June 2023 paper in the journal Aquatic Ecology, which he says was the first work to determine and compare the ecological status of his freshwater crabs Strengeriana fuhrmanni species in Colombia.

“I’m currently working to understand how anthropogenic changes such as urbanization, agriculture and ranching affect populations of endemic crabs in the Pseudothelphusidae family,” he says, adding that although crabs are sensitive to change and are often noted in studies environmental quality, were never a priority.

The study found that the distribution pattern of the crab in the city of Manizales, Colombia is declining due to urbanization that limits the dispersal and foraging area of ​​these crabs in streams in the city’s ecological parks.

“On the other hand, this was also a great opportunity, as it allowed us to find results such as identifying core areas, feeding relationships with other species such as frogs, and correlating environmental variables,” says Rivera.