Location codes in killifish refer to specific collection sites where a particular population or strain of killifish was originally found in the wild. These codes are essential for hobbyists, scientists, and conservationists to maintain genetic purity and track geographical variation within species.

Why Are Location Codes Used?

1. Preserving Genetic Purity – Killifish species often have unique adaptations based on their environment. Mixing different populations can dilute these traits, affecting their natural behaviors, colors, and survival strategies.
2. Scientific Study – Researchers use location codes to study population differences, evolution, and ecological adaptation.
3. Avoiding Hybridization – Many killifish species are closely related and can interbreed, leading to hybrid populations that may lose their natural characteristics.
4. Conservation Efforts – Some killifish populations are endangered or exist only in small, isolated habitats. Keeping track of their origins helps maintain their genetic integrity in captive breeding programs.

What Do Location Codes Look Like?

A typical location code includes:

• Species name
• A set of letters or numbers indicating the country, region, or specific collection site
• Sometimes the year of collection

For example:

• Nothobranchius rachovii Beira 98 – This indicates the species was collected near Beira, Mozambique, in 1998.
• Aphyosemion australe “Cape Esterias” – This means the population was found in Cape Esterias, Gabon.

Why It Matters in the Hobby

Many killifish keepers and breeders strictly maintain location codes to prevent crossbreeding. If a fish is labeled without a location code, it is generally considered a “generic” or “aquarium strain,” which may have mixed genetics.

There are many location codes used for killifish, primarily to track wild-collected populations and maintain genetic purity. These codes usually include species names followed by the specific collection site and sometimes the year of collection.

Here are some examples:

Nothobranchius Species:

1. Nothobranchius rachovii Beira 98 – Collected near Beira, Mozambique, in 1998.
2. Nothobranchius furzeri Gona Re Zhou ZW 2003 – Found in Zimbabwe, Gona Re Zhou National Park, in 2003.
3. Nothobranchius kafuensis MZCS 08-108 – A strain from Zambia, collected in 2008.
4. Nothobranchius patrizii Tana River – Collected in Kenya’s Tana River region.

Aphyosemion Species:

5. Aphyosemion australe “Cape Esterias” – Collected from Cape Esterias, Gabon.
6. Aphyosemion gardneri Lafia – A strain from Nigeria, Lafia region.
7. Aphyosemion striatum Ogooué River – Found in Gabon, near the Ogooué River.
8. Aphyosemion bitaeniatum Ijebu Ode – A strain from Nigeria, Ijebu Ode region.

Fundulopanchax Species:

9. Fundulopanchax sjoestedti “Akure” – From Akure, Nigeria.
10. Fundulopanchax gardneri Nsukka – A Nigerian strain from Nsukka.
11. Fundulopanchax filamentosus Badagry NG 97 – Collected in Badagry, Nigeria, in 1997.

Simpsonichthys and Austrolebias Species (South American Killifish):

12. Simpsonichthys boitonei IUCN 2011 – Found in Brazil, a strain tracked by the IUCN.
13. Austrolebias nigripinnis “Las Flores” – Collected in Argentina, Las Flores region.
14. Cynolebias perforatus Barreiras BA 2012 – Found in Bahia, Brazil, collected in 2012.

Each of these codes helps maintain genetic integrity and prevents hybridization in breeding programs.