Researchers in Turkey recently rediscovered the Batman River loach, a species that hadn’t been seen since 1974.
There have been many prior unsuccessful attempts to find the species, leading to speculation that it may have gone extinct.
While very little is known about the species, experts believe that it was impacted by the construction of the Batman dam.
The scientists found the species in a part of the river that’s upstream of the dam.
For about a decade, ichthyologist Cüneyt Kaya had made it a quest to search for the critically endangered Batman River loach (Paraschistura chrysicristinae), a tiny, orange-and-brown-striped freshwater fish once found in the Batman and Ambar rivers in Turkey. But no one had spotted the fish since 1974, leading to speculation that the species had gone extinct.
But on Oct. 16, Kaya and his colleague, Münevver Oral, caught an unfamiliar fish in their net while on a research trip to look for another species in the upper Batman River in eastern Turkey.
“We came out of the water and I remember he [Kaya] was very excited,” Oral, a geneticist and research fellow at Recep Tayyip Erdoğan University, told Mongabay in a joint interview with Kaya. “He opened his laptop and when he saw the original drawing [of the species], he was sure this species was Paraschistura chrysicristinae.”
“It was a great feeling,” said Kaya, an associate professor at the same university, “because this fish was in the 10 most wanted fish species in the world.”
Very little known about the Batman River loach. Shortly after the first specimens were collected in the 1970s, the species seemed to disappear, leaving a gaping hole in the scientific understanding of the species.
In 2021, wildlife NGOs Shoal and Re:wild listed the Batman River loach as one of the 10 most wanted freshwater fish species.
“There had been several attempts to find it and all of these had been unsuccessful … so there was the idea that it was extinct,” Freyhof told Mongabay in a video interview. “Only in discussion, we decided to list it as critically endangered [but] possibly extinct.”
While there are no documented threats to the Batman River loach, Kaya says he thinks the construction of the Batman dam, which took place in the 1980s and 1990s, led to its disappearance in parts of the river. The site where they ultimately found the species was a place called Sarim Stream, a section of shallow, rocky and fast-flowing water upstream of the Batman dam.
“Now we know where it is distributed and we know [which place] we should protect,” Kaya said. However, he added that they need more data to fully understand its distribution range and the threats facing the species.
Freyhof said that loaches tend to have “notoriously small ranges,” which makes them particularly vulnerable to changes in their environment.
According to a 2014 report published by the IUCN, 41% of freshwater fish in the Eastern Mediterranean region are threatened due to dams, pollution and excessive water extraction. The report also found that Turkey has the greatest number of freshwater species, including fish, but that these species face the highest number of threats when compared to other Eastern Mediterranean countries.
Kaya, Oral and Freyhof are currently working on a new paper about the Batman River loach.
Freyhof said the rediscovery of the species wouldn’t have been possible without the determination and passion of Kaya and Oral.
“They are a very successful, very productive scientific team,” he said. “It’s no surprise that they found this.”
Smith, K. G., Barrios, V., Darwall, W. R., & Numa, C. (Eds.) (2015). The status and distribution of freshwater biodiversity in the Eastern Mediterranean. Retrieved from IUCN website: https://portals.iucn.org/library/sites/library/files/documents/RL-262.2-001.pdf
Banner image caption: Cüneyt Kaya and Münevver Oral conducting research in the Batman River in Turkey. Image courtesy of Re:wild.
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