Guitarfish on Mexico’s medicinal market
Bryan is on a mission to know which guitarfish are marked as ‘pez diablo’. These are guitarfish species that are caught, cut and modified to have a ‘devil-like’ appearance to be sold in Mexico’s curio and medicinal markets. Of the nine species of this highly endangered group of shark-like rays occurring globally, 8 are found in Mexico. Using a combination of methods, Bryan will investigate which species are being sold in this way and create infographics to educate about Mexico’s 8 guitarfishes.
Bryan Huerta Beltrán
I was born and raised in Mexico City, yet during my childhood I always felt influenced by the natural world. Growing up in a mega-diverse country like Mexico made me interested in wildlife from a very young age. I can vividly remember talking with my father and uncle about the world’s unique creatures while we were sharing outdoor adventures in the countryside. However, my passion for animals did not end with my childhood; I decided to turn that early hobby into my professional career by pursuing an undergraduate degree in conservation and wildlife management in the USA. As a student...
The devil is in the details – molecular identification of guitarfishes sold as “pez diablo"
To document which guitarfish species are being marketed as ‘pez diablo’ in Mexico by using morphometric and genetic methods.
Of the nine recognised guitarfish species of the genus Pseudobatos in the world, eight have been recorded in Mexico. When caught, they are carved and modified in such a way as to look like devils and are then sold as ‘pez diablo’ for various purposes, including traditional medicines, or as curio items. To date, no studies have documented which guitarfish species are being marketed as ‘pez diablo’ in Mexico, even though seven of the eight species are considered threatened by the IUCN.
Shark-like rays of the order Rhinopristiformes are among the world’s most threatened elasmobranchs, given their vulnerability to overfishing, habitat destruction and pollution. Guitarfish make up one genus, Pseudobatos, within this order, which comprises nine species that are found exclusively in the New World. In Mexico, guitarfish are targeted for human consumption by commercial and artisanal fisheries and are sold fresh or dried. Pregnant females have frequently been observed aggregating seasonally in coastal Mexico, which makes them especially susceptible to being caught in large numbers and thus to declining populations. In particular, the shovelnose guitarfish P. productus was the primary elasmobranch landed in Sonora, northern Mexico, in 1998–1999.
Mexico has a long-standing tradition of using wildlife for a variety of medicinal purposes. Guitarfish sold in the country are routinely carved, shaped and dried to create a devil-like appearance and labelled as ‘pez diablo’, then sold alongside medicinal herbs and ‘witchcraft items’ or as curios. The tradition of modifying rays in this way was first reported in Europe as long ago as the 1550s, when they were referred to as ‘Jenny Hanivers’. Although ‘pez diablo’ is well-known and widespread in Mexico, few people are aware that it is made from threatened guitarfish species. Moreover, the common name ‘pez diablo’ is also used to describe a highly invasive sailfin catfish species that has severely damaged Mexican ecosystems. Understandably, the use of the term pez diablo for an invasive species and for threatened guitarfish causes confusion for the non-biologist.
- To collect samples of modified guitarfish sold as ‘pez diablo’ in Mexico from different vendors in Mexico City. Preliminary identification will be made in the field.
- To identify genetically guitarfish species sold as ‘pez diablo’. Genetic identification will confirm whether samples of ‘pez diablo’ can be accurately and reliably identified to species level by using identification guides, even though they have been modified and dried.
- To create for the non-biologist a supplementary infographic of the eight guitarfish species found in Mexico. An additional section will discuss the main differences between modified guitarfish ‘pez diablo’ and the invasive freshwater sailfin catfish also known as ‘pez diablo’.
Summary of main research results/outcomes:
· This project provides the first genetic reference library for all nine described amphi-American guitarfishes from the genus Pseudobatos, based on the mtDNA NADH dehydrogenase subunit 2 gene (ND2). This is particularly important as all guitarfishes of the genus Pseudobatos are listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and genetic data were missing for several species.
· The genetic reference library will help identify guitarfish species in highly processed products (e.g., meat, fins, modified guitarfishes, leather, etc.) across the Americas, supporting trade transparency and enforcement of international regulations, such as CITES. The library reliably identifies most Pseudobatos species, but two Pacific species require caution due to minimal genetic differences in ND2.
· The project documented in the literature the history, use, and trade of modified guitarfishes (i.e., when guitarfishes are cut, modified, and dried to resemble mythical creatures). Prior to this project, the modified guitarfish trade was largely unexplored and “invisible.” Modified guitarfishes come in various forms and are traded under distinct names (e.g., Jenny Haniver, Devil Fish, or Pez Diablo). These forms can be broadly grouped as devil-shaped or alien-shaped and are sold as curiosities or for medicinal purposes
· 33 modified guitarfishes were collected from Mexico City and the outskirts and were identified to the species level using the genetic reference. The findings revealed that guitarfishes are sourced from both the Atlantic and the Pacific oceans, with specimens identified as the Spadenose Guitarfish, Speckled Guitarfish, and the Atlantic Guitarfish, all of which are currently threatened with extinction according to the IUCN.