A super rare species of ray has been declared extinct after an assessment by an international team led by the Charles Darwin University (CDU) in Australia.
The loss of the Java Stingaree, a small relative of stingrays, is the first marine fish extinction recorded as a result of human activity. This news comes as the International Union for Conservation of Nature (IUCN) released its updated Red List of Threatened Species on the 11th of December 2023.
The Java Stingaree, Urolophus javanicus, was known to science from a single specimen collected in 1862 in Indonesia. 160 years later, the University team conducted new modeling encompassing all available information on the species which has revealed the Java Stingaree as extinct.
CDU PhD Candidate and lead assessor, Julia Constance said a range of issues had contributed to the Java Stingaree’s disappearance. “Intensive and generally unregulated fishing is likely the major threat resulting in the depletion of the Java Stingaree population, with coastal fish catches in the Java Sea already declining by the 1870s,” Ms Constance said.
“The northern coast of Java, particularly Jakarta Bay where the species was known to occur, is also heavily industrialized, with extensive, long-term habitat loss and degradation. These impacts were severe enough to unfortunately cause the extinction of this species,” she said.
As part of the assessment of the plight of the Java Stingaree, the team looked at known threats such as overfishing and habitat loss and whether the species had been recorded in fish markets through surveys.
CDU PhD Candidate Benaya Simeon who is studying threatened rays in Indonesia, said that despite extensive survey efforts since 2001, no additional specimens have been found. “A range of fish landing sites along the northern coast of Java and across Indonesia have been monitored extensively but they have not recorded the Java Stingaree,” Ms Simeon said. “The Java Stingaree was a unique dinner plate-sized ray with no similar species in Java and the fact it has not been found during innumerable surveys confirms its extinction.”
CDU’s Research Institute for the Environment and Livelihoods Senior Research Fellow Dr Peter Kyne said there are over 120 Critically Endangered marine fishes in the world and that the loss of the Java Stingaree is a tipping point for marine biodiversity. “The Java Stingaree being named as extinct is a warning sign for everyone across the world that we must protect threatened marine species,” Dr Kyne said. “We must think about appropriate management strategies like protecting habitat and reducing overfishing while also securing the livelihoods of people reliant on fish resources.”
The IUCN’s Red List of Threatened Species is the world’s most comprehensive source on the global extinction risk and status of animal, fungus, and plant species. Established in 1964, the IUCN Red List has identified over 41,200 species threatened with extinction globally. The IUCN Red List lists 15 species of Urolophus Stingaree, with one Data Deficient, one Near Threatened, three Vulnerable, one Endangered, and now one officially Extinct.
Eight species are listed as Least Concern, with stable populations. The Java Stingaree, Urolophus javanicus, was described and first named by German zoologist Eduard von Martens in 1864, who then named it Trygonoptera javanica. His description was based on a single 33 cm (13 in) female specimen that he purchased from a fish market in Jakarta, Indonesia.
Photo credit: Edda Aßel, Museum für Naturkunde Berlin.
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