The Blue Halfmoon Koi Betta is one of the most captivating freshwater fish varieties available to aquarium enthusiasts today. A refined combination of dramatic finnage and vibrant marbled coloration, this betta variety represents years of selective breeding built upon the foundation of the species Betta splendens.
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| Live Male Blue Koi Halfmoon Tail Betta Fish (source) |
Known commonly as the Siamese fighting fish, Betta splendens has evolved far beyond its wild ancestors, and the Blue Halfmoon Koi stands as a striking example of how art and biology intersect in the aquarium world.
Note: If you are interested in buying the betta fish on this page, click the link source to contact the sellers. Some bettas may still be ready or even have been sold.
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| Halfmoon Koi Fancy Blue Tail Betta Fish (Source) |
📘 Ready to raise a healthy, beautiful betta? Start with the right guide.
What makes the Blue Halfmoon Koi Betta unique is the fusion of two distinct traits: the “Halfmoon” tail shape and the “Koi” color pattern. The Halfmoon trait refers to the fish’s caudal (tail) fin, which spreads to a complete 180-degree semicircle when fully flared. Learn guide for betta fish completery
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| Yellow Blue Koi Halfmoon Tail Betta Fish (Source) |
This symmetrical fan-like display gives the fish a dramatic, flowing appearance, almost resembling a delicate silk fan opening underwater. The fins are typically broad, evenly rounded, and highly structured, creating a balanced silhouette when viewed from the side.
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| Halfmoon Blue Dragon or Line Koi Size Medium (Source) |
The “Koi” aspect refers to its marbled coloration inspired by traditional Japanese koi carp. While koi carp belong to a completely different species, breeders adopted the name because of their similar patchwork coloration.
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| Blue Cellophane Koi Halfmoon Tail Betta Fish (Source) |
In Blue Halfmoon Koi Bettas, a rich, electric or steel-blue base color is accented by splashes of white, red, yellow, orange, or even black. No two fish are ever identical. Each individual carries its own unpredictable pattern, making every specimen a living piece of aquatic art.
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| Blue Koi Giant Halfmoon Betta Fish Size 4,1 Cm (Source) |
One of the most fascinating characteristics of Koi-patterned bettas is the marble gene. This gene causes pigmentation to shift and change over time. A Blue Halfmoon Koi Betta purchased as a juvenile may look noticeably different several months later. Blue patches can intensify, white areas may expand, and red markings can deepen or fade. This dynamic transformation adds an element of anticipation and surprise for owners.
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| Live Male Blue Raspberry Koi Halfmoon Male Betta (Source) |
In terms of temperament, Blue Halfmoon Koi Bettas share the classic betta personality. Males are highly territorial and should be housed alone or in carefully managed community tanks. Their long, flowing fins make them poor candidates for housing with fin-nipping species. Females, while generally less aggressive, can also display territorial behavior depending on individual temperament.
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| Blue Yellow Koi Halfmoon Tail Betta Fish Size M (Source) |
Proper care is essential to maintain both health and coloration. These bettas thrive in heated aquariums between 24–28°C (75–82°F) with gentle filtration. Because of their elaborate finnage, they should be avoided in strong water currents.
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| Male Halfmoon Koi Blue Marble Betta Size M (Source) |
A tank size of at least 5 gallon aquarium is recommended to provide adequate swimming space and stable water parameters. A high-quality diet consisting of protein-rich pellets, frozen foods, and occasional live treats will enhance coloration and support fin development. Other patterns, like HMPK samurai is also great betta fish.
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| Beautiful Betta - Koi Candy Blue Opaque Halfmoon Male (Source) |
Lighting can also help showcase their brilliance. Under proper aquarium lighting, the blue tones often shimmer with metallic iridescence. When the fish flares its fins, the Halfmoon spread, combined with koi-style marbling, creates a display that is both bold and elegant.
The Blue Halfmoon Koi Betta is more than just a pet fish; it is the result of careful genetic selection and artistic breeding vision. For hobbyists seeking a centerpiece fish with personality, movement, and ever-changing beauty, this variety offers a remarkable blend of sophistication and individuality.
