XNP project annual report – year 4

The Xiphophorus – Northern Platyfish project has completed its fourth year. In the second half of this period, we were able to recover from the Covid-19 restrictions and almost get back to the usual operations. Meeting and travelling was still very limited, but we managed to make at least one big transfer of fish from Central Europe to the West and distribute X. couchianus to several breeders in France, Germany, Belgium and Netherlands. Some minor transfers between individual breeders also took place.

Overall, this was a year of further expansion of the project with more institutions joining us (zoos and public aquaria) and finally founding the Xiphophorus Working Group on the basis of the XNP project.



Here are the numbers of fishes kept and how they evolve since the start of our project (as of the beginning of 2019, 2020, 2021 and 2022, respectively):

Xiphophorus meyeri Spotted:            434 - 645 - 1145 - 1436

Xiphophorus meyeri Wild Type:        93 - 180 - 109 - 37

Xiphophorus couchianus:                  114 - 180 - 438 - 664

Xiphophorus gordoni:                        29 - 63 - 56 - 18

Xiphophorus sp. "Apodaca":             12 - 0 - 0 - 0

Xiphophorus sp. "Regio":                  19 - 110 - 83 - 86

Total number of fish:                         701 - 1178 - 1831 - 2241

The positive trend continues for both X. meyeri (spotted) and X. couchianus, while we have not so good results for the wild type of X. meyeri – some groups were lost again and only one project member continues to maintain a prosperous breeding group. In reaction to this, we have set up several mixed groups, where we hope to crossbreed the spotted and wild form. The wild form is recessive and we need to keep this strain present in the genetic pool (even if the gene is carried by a spotted fish).

Furthermore, we keep struggling with effective husbandry of X. gordoni. Only one breeding group is maintained now, but its condition has improved and we need to focus on this species. It is very susceptible to Mycobacterium, and fighting this infection was one of our priorities for the fourth year of the project. The current stock seems stable and more resistant, but we need to further work on this issue.

Xiphophorus sp. "Apodaca" was the second priority for this year, and we can only confirm that this fish is now lost in Europe and very probably also in Mexico.



Currently, the project has 42 members (compared to 28 previous year) from nine countries. We have seen the recruitment of new members mainly from France, Germany, the Czech Republic and UK. New institutions have joined us: Leipzig Zoo, Tierpark Berlin, Rotterdam Zoo and Aquarium Tropical Paris.



Some institutions have placed the northern platyfish in exhibition tanks and produced educational materials about our conservation efforts, especially the Leipzig Zoo from Germany. Interesting articles about northern platyfish, their conservation and/or husbandry were published in some European countries, notably in France.

Last, but not least, we have published updated version of the „Northern Platyfish Husbandry Manual“, which serves as the distilled overview of our knowledge and experience.



Very important milestone of our project was the founding meeting of the Xiphophorus Working Group in October 2021, held together with the annual conference of the Goodeid Working Group hosted by the Ostrava Zoo, Czech Republic. We could finally meet in person after long time and the discussion of Xiphophorus conservation was very interesting and effective. XWG will work on similar principles like the XNP project, which remains unchanged under the guidance of the ÖVVÖ. XNP project has clearly shown that cooperation of breeders from different countries is possible and brings positive results. We have used this occasion to transfer fish, which was very much needed after the long break.

There is no change of the financial status, i.e. all expenses are covered by the respective members individually and the project balance is zero.

New project manager deputy was named: Torsten Friedrich from Germany. This position was vacant until now. Torsten is one of the first XNP project members since March 2018, he has breeding experience with several species of northern platyfish, and his positive attitude has always been helpful.


Future plans

We want to continue addressing the problem of Mycobacterium infection and overall health condition (especially in X. gordoni), incorporate the XNP project into new Xiphophorus Working Group and establish cooperation with Mexican partner to investigate the possible support of conservation of northern platyfish in their home country.


I want to thank once again all members of the XNP project. You are protecting rare species from extinction!

Markéta Rejlková

8.5.2022, Ostrava, Czech Republic

ÖVVÖ conservation project