A new species of Whipray from the Himantura genus has been described with the help of DNA Barcoding.
|Leopard Whipray (Himantura leoparda)|
The researchers took tissue samples from 115 spotted whiprays which were collected throughout the Indio-Pacific region. The group was initially thought to contain 3 species (Himantura leoparda, Himatura uarnak, Himantura undulata). However, after analysis it became clear that there was a previously unidentified species among the DNA samples. These new leopard-skin whiprays — which have been reproductively isolated from the other species for quite some time — have been named Himantura tutul. All four species occupy the same costal habitats but apparently subsist in separate ecological niches.
These studies should help to assess the state of these whipray populations and improve their conservation. Knowing the biological characteristics of each species will for instance help to redefine a minimum size for fishing purposes to avoid the catching of juveniles that belong to the larger species. Determining their geographical distribution and habitats will also make it possible to protect the breeding and nursery habitats of each species.
Ocellated whiprays can grow over 1.50 meters wide. These large animals start breeding fairly late, at the age of 5 or 10 years, and only in small numbers. Their populations are therefore very vulnerable. Fished for food and especially for their skin that is sold to tanneries in South-East Asia, they are threatened almost throughout the tropical Indo-West Pacific. Their overfishing will in time jeopardise a whole segment of the economy in Indonesia, which is the largest shark and whipray exploiter with 30% of all catches worldwide. In less than twenty years, the amount fished in the Java Sea has been divided by ten! As high-level predators, whiprays also play an important role in regulating ecosystems. Their extinction will threaten the functioning of coastal marine environments. Ocellated whiprays have one or two venom glands at the base of their tail to protect them against their natural predators, namely sharks and killer whales. Their sting is painful and potentially infectious, with serious consequences if not treated correctly.
According to the International Union for Conservation of Nature's Red List over 36% of the 650 known ray species known are currently at least endangered. This also includes the leopard whipray (Himantura leoparda) , which is currently classified as ‘vulnerable’. There is quite some confusion within the genus Himantura as they are really difficult to tell apart and a couple of new species have been described in the last years. This could mean that the current status might not reflect the true situation in this group.