According to available data, the rarest betta fish species and color variations mainly fall into the following categories:
I. Rare Mutant Varieties
Double-Tailed Betta
Caused by genetic mutation, the caudal fin splits into two parts, forming a rare double-tail structure. Historically, this variety has been extremely elusive.
Elephant Ear Betta
The pectoral fins are abnormally broad, resembling floppy ears, commonly seen in improved strains of Halfmoon or Plakat bettas. Its swimming motion creates a distinct visual effect.
II. Rare Individuals with Special Color Morphs
Black Diamond Betta
Covered in deep black pearlescent scales that reflect purple under infrared light, only 7 individuals exist globally (5 held in the Japanese imperial collection). Its genetic value is 17 times that of the Neon Betta.
Neon Tri-Color King
Displays a gradient of red, blue, and gold simultaneously. With fewer than 200 individuals worldwide and a survival rate below 5%, it once sold for a record 280,000 RMB.
Blue Diamond Betta
Features metallic blue patterns from a rare algal infection (infection rate 0.0003%). Currently, only 3 aquariums hold breeding rights.
Xanthic Betta
Exhibits a unique yellow hue due to abnormal xanthophyll metabolism. Juvenile mortality reaches 90%, with existing individuals comprising less than 0.7% of the total population.
III. Endangered Wild Original Species
Wild Discus Fish
Due to Amazon rainforest destruction and illegal fishing, wild individuals are extremely rare in the aquarium trade.
Original Thai Betta
Compared to domesticated varieties, wild individuals retain their primitive wild beauty but are increasingly scarce due to habitat loss.
IV. Rare Phenotypes of Chinese Bettas
Premium Round-Tailed Betta
Must meet strict criteria: strong symmetrical pectoral fins, intact scales, and a balanced body. High-quality individuals showcase vibrant coloration during the spawning season.
Note: Rarity is influenced by genetics, habitat, and selective breeding. Some varieties (e.g., Double-Tailed and Black Diamond) have minimal populations due to genetic defects or mutations, while wild originals face endangerment from ecological degradation.