Berlin Swordtail Swordtail
Xiphophorus hellerii
About this strain
A red-and-black bicolor strain where the body shows bold, irregular black markings or a heavy black reticulation over a red base, creating a mosaic-like pattern more complex than the clean two-tone of the tuxedo. Some descriptions place the Berlin as a specific line with a characteristic black dorsal and heavy flank spotting. It's one of the more variable strains in terms of pattern expression — no two fish look identical. Developed with show-quality standards in mind; well-bred Berlins are noticeably more refined in body shape and finnage than mass-market fish.
Origin
Developed in Germany, as the name suggests, by dedicated livebearer breeders aiming for a show-standard bicolor swordtail strain. Refined primarily through European hobbyist clubs in the mid-to-late 20th century.