A groundbreaking study published in the January 2025 issue of the Regional Studies in Marine Science has confirmed the presence of the deadly Chironex yamaguchii box jellyfish in the Philippines' Coral Triangle region, alongside its distribution and genetic diversity in Okinawa, Japan.
Led by Dr. Sheldon Rey Boco from The Philippine Jellyfish Stings Project and Griffith University in Queensland, Australia, the study is based on specimens collected in the central Philippines in 2016 and 2019—six in 2016 and 14 in 2019—confirming the presence of one of the world’s most venomous jellyfish species.
Boco, alongside a team of researchers from Griffith University and several Filipino institutions, including the University of the Philippines Diliman and Samar State University, conducted physical and genetic analyses of the jellyfish.
Using advanced molecular techniques such as cytochrome oxidase I (cox1) and ribosomal RNA (16S), the team uncovered genetic differences within the species that were previously undetectable by physical examination alone.
Boco said the new insights into the species' genetic diversity are crucial for understanding its spread and potential risks.
“This study focuses on the box jellyfish, Chironex spp. which are some of the most venomous animals, causing severe stings and even deaths in the Indo- and Western Pacific regions where the Philippines is located. Their tentacles can cause extreme pain, skin injuries with welts, heart attacks, and death.,” Boco said in an email to the Manila Bulletin.
“In the Philippines, many coastal communities are aware of the severe stings and fatalities caused by Chironex. This study is important because it shows genetic differences within the species Chironex yamaguchii that we couldn't see just by looking at them as physical specimens. This finding highlights how important it is to use molecular methods to correctly identify species and understand their genetic variety,” he added.
The findings have significant public health implications, particularly in the management and prevention of jellyfish stings.
Boco said accurate species identification of Chironex yamaguchii—a critical step in understanding its genetic diversity and distribution—is essential for effectively treating and managing stings.
The study also helps in risk assessment by identifying the different genetic populations of the species in various regions, which aids in evaluating the risk of stings in those areas and protecting local communities and tourists.
Boco also noted that better knowledge of the jellyfish's distribution and genetics can help healthcare providers be more prepared to treat sting cases, improving patient outcomes.
In terms of public awareness, Boco emphasized that understanding the presence and dangers of Chironex yamaguchii could lead to preventive measures, such as avoiding certain areas during peak jellyfish seasons and using protective gear.
The study also provides valuable data to help policymakers create regulations and guidelines for beach safety, including monitoring and managing jellyfish populations to reduce sting risks, he said.
Boco pointed out that collaboration played a key role in the study's success, with researchers from multiple institutions across Australia, the Philippines, the United States, and Japan contributing their expertise and resources.
The species was documented by a team of academics from Griffith University in Queensland, Australia, including Boco (first author, Filipino, and study lead), Dr. Phuping Sucharitakul, and Dr. Jonathan W. Lawley.
Additional contributors included Christine Gloria Grace Capidos from Samar State University in Catbalogan, Philippines; Raffy Jay Fornillos, and Ian Kendrich Fontanilla from the DNA Barcoding Laboratory of the Institute of Biology, UP Diliman; Dennis Talacay from The Philippine Jellyfish Stings Project in Tacloban, Philippines; Joseph Elliz Comendador from the National Museum of the Philippines; and Dr. Allen G. Collins from the National Oceanic and Atmospheric Administration's National Systematics Laboratory and the Smithsonian Institution National Museum of Natural History in Washington, D.C.