Identifying species from a single caviar egg

Research Press Release | May 30, 2017


A new tool enables identification of high-end caviar from Beluga sturgeons by analyzing DNA from a single caviar, a development that helps ensure the fair international trade of caviar and contributes to conservation of the species in the wild.

The fish species Beluga sturgeon is known to produce the best caviar, large eggs with a delicious taste, and are therefore traded at high prices. The number of Beluga sturgeons plunged over the past century due to overfishing and deterioration of their natural habitat. They are listed as critically endangered species and international trade is strictly controlled under the Washington Convention (Convention on International Trade in Endangered Species of Wild Fauna and Flora).

The decline in the natural population of Beluga has led to the development of various sturgeon cultures across the world. In particular, Bester (a hybrid between a Beluga and a Sterlet) is considered suitable for culturing to produce caviar. It is, however, virtually impossible to identify the species of eggs by merely looking at their appearance.

Hokkaido University researchers, in collaboration with the Czech Republic’s University of South Bohemia, have now identified DNA sequences that distinguish Beluga and Sterlet from eight other sturgeon species. Using the modern method of molecular genetics, the team identified species-specific variants in the genome of Beluga and Sterlet sturgeons. Taking advantage of these variants, they have developed a simple method using polymerase chain reaction (PCR) which detects targeted variants, enabling Beluga caviar to be identified and distinguished from Bester and other species.

“The new tool developed in our research can accurately and swiftly identify Beluga caviar at a low cost, which will help international trade of this gourmet food to be conducted fairly. It should also help manage sturgeons as a resource, thereby protecting the diversity of the species,” says Miloš Havelka at Hokkaido University.

Original article:

Havelka M., Fujimoto T., et al., Nuclear DNA markers for identification of Beluga and Sterlet sturgeons and their interspecific Bester hybrid, Scientific Reports, May 10, 2017.

DOI: 10.1038/s41598-017-01768-3

Funding information:

The study was supported by the Japan Society for the Promotion of Science (JSPS), KAKENHI Grant numbers 21658067, 24248033, and 14F04751. The latter grant provided the Postdoctoral Fellowship for Overseas Researchers to Miloš Havelka (ID No: P14751). The study was also supported by the Ministry of Education, Youth and Sports of the Czech Republic projects CENAKVA (No.CZ.1.05/2.1.00/01.0024) and CENAKVA II (No. LO1205 under the NPU I program).


Associate Professor Takafumi Fujimoto

Faculty and Graduate School of Fisheries Sciences

Hokkaido University

Email: fujimoto[at]

Specially Appointed Assistant Professor Miloš Havelka

Faculty and Graduate School of Fisheries Sciences

Hokkaido University

Email: miloshavelka[at]

Naoki Namba (Media Officer)

Global Relations Office

Institute for International Collaboration

Hokkaido University

Tel: +81-11-706-2185

Email: pr[at]