New species of stingray described from the tropical South-Western Atlantic

The newly desrribed Hypanus berthalutzae, picture credit João Luiz Gasparini

We asked ichthyologist Flavia F Petean Ph.D. about Hypanus berthalutzae, and the women’s rights campaigner it’s named after.

Was the species previously known or mistaken as something else (another already described species,) before you described it?

It used to be the widely distributed species Hypanus americanus, which was thought to occur from New Jersey (USA) to Sao Paulo (Brazil). We found out that southern of the Amazon river mouth it is not H. americanus, but the distinct species. 

How did you tell it apart from its congeners?

We used an integrative taxonomic approach combining both morphology, genetics, and ecology to differentiate this new stingray lineage to other closely-related ones.

Its clearest morphological distinguishable feature are the black spots on its dorsal side. But there are also some differences in clasper morphology, which is the reproductive organ of stingrays. Therefore, these differences are probably related to evolutionary sexual selection as well, even though not tested yet. Besides, there are some clear genetic differences to other Hypanus species, and a unique geographic distribution and environmental characteristics of the area it occurs.

H.berthalutzae can reach five feet across, picture credit João Luiz Gasparini

What size does it grow to?

We have not measured any large specimen observed alive, but literature reports up to 150cm/60” disc width.

Why is it named berthalutzae?

The specific epithet is in honour to Bertha Lutz, a pioneering Brazilian woman zoologist, who was also involved in feminist issues and created the Brazilian Federation for Feminine Progress, which led the female suffrage in Brazil.

She represents women’s strength in Brazil who not only work for science development but also fight for women’s rights. Since this species of stingray is restricted to the Brazilian waters and most known specimens are females, it represents the recent feminine empowering, including in sciences

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Is it a food fish, sport fish or aquarium fish?

It is commonly fished in North and Northeastern Brazil for food consumption. There are many common/regional dishes that use stingrays.

Lutz’s stingray is also known as the Rockray, Butterray and Nailray, picture credit João Luiz Gasparini

Does it have a local name or common name?

Since it is endemic to Brazil, its common names in Portuguese among fishermen, tourists, and consumers are “Raia de Pedra” (rockray), “Raia Manteiga” (butterray), “Raia Prego” (nailray). In English, it could be “Lutz’s stingray.

How did you come to work on it? What started the whole process?

During my Ph.D. at the Universidade Federal of Rio Grande do Norte, under the supervision of Dr. Sergio Lima, I decided to study the widely distributed species Hypanus americanus because we hypothesized there could be more than population along the Americas’ coast.

Then, I got a Fulbright scholarship to do part of my research at the University of Florida, under the supervision of Dr. Gavin Naylor. When we sequenced and analyzed the mitochondrial genomes of the stingrays, we realized how distinct H. berthalutzae was from H. americanus. So, we combined all sources of information (genetics, morphology, and ecology) to analyze the extent of its distinctiveness to congeners and evaluate if a new species should be described.

Flávia de Figueiredo Petean, Ph.D. in Systematics and Evolution ,with Hypanus berthalutzae

How long did it take in total to describe and publish it?

We started collecting samples for genetic studies and doing the ecological niche modeling in 2016 when we started suspecting there could be a new species. But it took a long time to collect more samples from distinct locations for genetic analyses and to visit museums to study their morphology.

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So, it took approximately 4 years from the idea we had, to data collection and analyses, to publication of H. berthalutzae.

Thank you to Flavia for giving us the time to answer our questions. Picture credits João Luiz Gasparini.

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