Kochi, Aug 5: Scientists have resolved more than 150 years of confusion over the identification of thorny seahorse species using a seahorse collected from fish bycatch at the Tuticorin Fisheries Harbour in Tamil Nadu.
An international team led by the Kerala University of Fisheries and Ocean Studies (KUFOS), Kochi, has identified from the Indian Ocean, a new species that is taxonomically distinct from those found in the Pacific Ocean and the South China Sea.
Their study has found that the iconic thorny seahorse, long believed to be a single species ranging from the Red Sea and East Africa across the Indian Ocean to the western Pacific, is in fact three distinct species.
“These findings end more than 150 years of taxonomic confusion and provide an important foundation for future conservation of the world’s seahorses,” the study said.
The findings, published in the journal Zootaxa, are expected to reshape the understanding and conservation of one of the world’s most recognisable marine fishes, a KUFOS release said here on Wednesday.
The newly described species, Hippocampus amandavincentae, has been named in honour of Amanda Vincent, one of the world’s leading seahorse experts, marine biologist and founder of Project Seahorse.
The breakthrough began when Shalu Kannan, the lead author who recently completed her PhD on seahorse conservation at KUFOS, collected specimens from heaps of fish bycatch at the Tuticorin fisheries harbour.
“Accurate species identification is a crucial first step towards understanding distribution, population status, and developing effective conservation strategies. This discovery reveals the hidden biodiversity in the Indian Ocean and highlights the importance of documenting and protecting its unique species and the critical habitats they depend on,” Shalu said.
Although thorny seahorses are among the most recognisable members of the genus Hippocampus, their outward similarity had hidden important differences for more than a century.
By combining detailed studies of body features with molecular analysis and examining historic museum specimens from around the world, the researchers showed that Hippocampus amandavincentae can be distinguished from other spiny seahorses by its snout length and the number and nature of spines on the coronet and the principal trunk and tail ridges.
DNA analysis further confirmed the distinction, showing a 7.0 per cent genetic distance between the new species and the true thorny seahorse, Hippocampus histrix.
The study also redraws the known range of the species.
While Hippocampus histrix is now confined to the Pacific Ocean and the South China Sea, including waters off Japan, Indonesia and the Philippines, Hippocampus amandavincentae is distributed across the Indian Ocean, with confirmed specimens from the Bay of Bengal and the Laccadive Sea, and additional verified genetic or photographic records from Madagascar, Mozambique and the Seychelles.
The researchers also confirmed that Hippocampus jayakari, first described in 1900 from the Gulf of Oman, is a valid species of spiny seahorse restricted to the northwestern Indian Ocean.
Rajeev Raghavan, Assistant Professor at KUFOS and a senior author of the study, said many museum specimens and online biodiversity records of spiny seahorses in the Indian Ocean have been assigned to Hippocampus histrix for decades.
“Our findings now reveal that these records actually represent multiple species, with practical consequences for global conservation decision-making and policy implementation,” he said.
Raghavan said resolving the distribution of the three spiny seahorse species would have significant implications for their future assessment under the IUCN Red List.
Seahorses are considered flagship species and indicators of healthy coastal marine ecosystems.
However, they face threats from habitat loss, overexploitation for traditional medicine and the aquarium trade, and accidental capture in commercial fisheries.
Graham Short, a co-author of the paper and research associate in Ichthyology at the Australian Museum and the California Academy of Sciences, said the Indian Ocean spiny seahorses are cryptic, have been handled by science for over a century, but never recognised as their own.
“We have finally given them a name: Hippocampus amandavincentae, for Amanda Vincent, whose work established seahorse conservation as a field,” Short said.
“The discovery of a new species of an iconic fish such as a seahorse from fish landing centres highlights how much remains to be learned about marine biodiversity, even in places that are visited and studied every day, and from bycatch that would otherwise have been discarded,” said K Ranjeet, Professor at KUFOS, who supervised the lead author during her PhD. (PTI)
