Research · New Study

Two Look-Alike Whipray Species Meet in Mozambique

October 7, 20265 min read

Large spotted whiprays along Africa’s east coast are notoriously difficult to identify. A new genetic study confirms that at least two distinct species occur in the Western Indian Ocean, that both live side by side in Mozambique, and that their spot patterns are not a reliable guide to which is which.

A difficult group to name

Whiprays of the genus Himantura are large, bottom-dwelling stingrays with long, whip-like tails. They inhabit coastal waters and estuaries from East Africa to the East China Sea, where fishing and habitat degradation threaten their populations, and most species in the genus are listed as Endangered on the IUCN Red List. Identifying them, however, relies mainly on their color patterns and body shape, which vary between individuals and as a ray grows. As a result, whiprays are frequently misidentified, both in the field and in the catch records used to manage fisheries.

Sampling and genetic analysis

The study, published in Marine Biodiversity (opens in a new tab), was led by Karla Redelinghuys of Stellenbosch University in South Africa. Its co-authors include researchers from the Wildlife Conservation Society, the Oceanographic Research Institute, and King Abdullah University of Science and Technology, along with MMF Research Associate Dr. Stephanie Venables and MMF’s Dr. Andrea Marshall.

The team analyzed samples from 93 whiprays collected between 2018 and 2024 in South Africa, Mozambique, Tanzania, Saudi Arabia’s Red Sea coast, and Qatar. MMF facilitated sample collection in Mozambique, where most samples were taken by divers from free-swimming rays. The researchers sequenced three mitochondrial genes (DNA inherited through the mother and widely used to distinguish species) and compared them with published sequences from the wider Indian Ocean and western Pacific. Five separate analytical methods then sorted the sequences into genetically distinct groups, and a group was accepted only where at least three of the methods agreed.

Two species overlap in Mozambique

Across all three genes, the whiprays sampled for the study fell consistently into two groups, which were genetically distinct enough to indicate two different species. One group occurred in South Africa, Mozambique, and the Red Sea, and the authors provisionally identify it as the leopard whipray (Himantura leoparda). The other occurred in Tanzania, Mozambique, the Red Sea, and Qatar, and is provisionally identified as the reticulate whipray (Himantura uarnak). The names remain provisional because few type specimens (the reference specimens that anchor scientific names) have been genetically sequenced, and the validity of a replacement type specimen designated for the reticulate whipray is still debated among taxonomists.

In Mozambique, both species were found at sites in the far south, near the border with South Africa, and around 500 kilometers (310 miles) to the north, in the Bazaruto Archipelago and at San Sebastian, with no apparent geographic divide between them. The authors describe Mozambique as a contact zone between the two species, a pattern that has also been reported for Critically Endangered wedgefishes.

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A wedgefish over pale sand in shallow water, with a group of whiprays resting behind it — A wedgefish in the shallows of the Bazaruto Archipelago, with whiprays resting behind it.

Spot patterns and database errors

The study also shows that the spot patterns on a whipray’s back cannot reliably separate the two species. Two large adult females from South Africa, both more than 1 meter (3.3 feet) across and identified in the field as different species because of their distinct spotting, belonged to the same genetic group. In contrast, rays that looked alike and were both identified as reticulate whiprays fell into different groups. One ray from Tanzania carried three different spot patterns on a single animal.

A whipray identified in the field as a reticulate whipray, sampled for genetic analysis in 2022. Spotting like this cannot reliably tell the two species apart.

Public DNA databases add to the confusion. The same genetic lineage appears in them under three different species names. For instance, the published mitochondrial genome of a leopard whipray is labeled as a reticulate whipray on GenBank, a widely used public DNA database. Errors of this kind carry through into later studies and, ultimately, into catch reporting.

Conservation implications

Until the two species can be named with confidence and reliably identified in the field, the authors recommend managing the Western Indian Ocean whiprays as a single conservation unit, while studying each species’ life history, habitat use, and vulnerability separately. This precautionary approach is intended to protect both species while avoiding the errors that misidentification introduces into fisheries monitoring. Leopard whiprays predominate in South Africa and reticulate whiprays in Tanzania, which suggests that the two countries may need different priorities. However, the authors single out Mozambique, where the species overlap, as a region that warrants particular attention.

“We’ve been photographing whiprays in the Bazaruto Seascape for years, often unsure whether we were looking at one species or two. Confirming that both species exist side by side here in Mozambique highlights the region as a critical location to better understand these rays and how fishing impacts their populations,” says MMF’s Dr. Stephanie Venables, co-author on the study.

“We now know that spot patterns alone can’t tell these rays apart, so neither divers nor fishers can reliably identify them by eye, and that means catch records may not accurately reflect which species is being caught. With most whiprays already listed as Endangered, managing both species together is the safest approach for now, while we work out the different pressures faced by each species.”

The study builds on the same team’s complete mitochondrial genomes of both species, published earlier this year. For future research, the authors recommend sequencing the leopard whipray holotype (the specimen used to describe the species) held at CSIRO, adding nuclear DNA markers, sampling under-represented areas such as Kenya and Somalia, and identifying physical features that allow reliable identification in the field.

The study was supported by the National Research Foundation of South Africa and the Wildlife Conservation Society. In Mozambique, The Sanctuary (Santuário Bravio de Vilanculos), Bazaruto Archipelago National Park, African Parks, the National Administration of Conservation Areas (ANAC), and the Oceanographic Institute of Mozambique (InOM) provided research permits and field support. Read the full study (opens in a new tab) (open access). Learn more about MMF’s shark and ray research in Mozambique, or make a donation to support new research on the region’s rays.

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