Racovitza's Rudd Captive Breeding Program

The Racovitza's Rudd (Scardinius racovitzai) was endemic to a single location comprising a small, thermal lake, from which it was extirpated in September 2014. Ex-situ stocks are currently maintained by institutions in Hungary, Czech Republic and Austria, holding the last remaining populations of this species.The sole habitat, a thermal Lake Baile 1 Mai in western Romania was destroyed by rerouting the thermal underwater springs to supply establishments associated with the recreational uses of the thermal waters. The Lake subsequently carried only small amounts of water in spring and has completely dried up since 2022.

Measures

Wild individuals of this species were collected and transferred to the Țării Crișurilor Museum in Oradea in 2012. Some of these individuals were later transferred to the Hungarian University of Agriculture and Life Sciences (MATE, formerly Szent István University) in Budapest, Hungary and were successfully reproduced. A Racovitza's Rudd population was then brought to Schönbrunn Zoo in 2014. At Schönbrunn Zoo, the species could be successfully bred multiple times via hormonal injections. Therefore, a stable stock could be established.
The ex-situ stock of the species is bred and kept at different locations to establish multiple ex-situ populations of the species and facilitate exchange between Țării Crișurilor Museum (Oradea, Romania), Răsvan Angheluțăq Museum of Natural Sciences (Galați, Romania), MATE, Schönbrunn Zoo (Vienna, Austria), Plzeň Zoo (Plzeň, Czechia) and Tropicarium (Budapest, Hungary).

Schönbrunn Zoo, holding the largest number of individuals, supports breeding initiatives and, together with Prof. Müller (Natural History Museum in Oradea, Romania), studied the possibilities of artificial insemination. After regular breeding and hormonally induced breeding in previous years, a stripped artificial insemination was tested twice in Vienna with Prof. Müller and his team. Eventually, the species could be successfully reproduced in Romania in 2025 and Schönbrunn Zoo received 86 juveniles and incorporated them to the existing stock in a newly designed and implemented keeping and breeding facility – the “Aqua-Forschungsstation”. The facility provides space for this EW (Extinct in the Wild) species and the aquaria meet consistent thermal water conditions of mean 29°C for S. racovitzai.

Aim

The aim of the project is to secure the long-term survival of the Racovitza's Rudd (Scardinius racovitzai).
This is how Schönbrunn Zoo is supporting the project:

• Collaborative keeping and breeding of this EW species
• Studying the possibilities of artificial insemination for conservation breeding
• Public relations work

Anton Weissenbacher, Curator of Zoology at Schönbrunn Zoo: “The Racovitza´s Rudd clearly demonstrates the important role zoos play in conserving endangered species, some of which are even extinct in the wild. A re-establishment of the species in the wild is currently not possible due to the complete lack of stable conditions for the species. Our “Aqua-Forschungsstation” now allows the consistent conservation of the species and an exchange with partner institutions. We have the largest stock of the species and are equipped to conserve the species over a long period of time.”