Freshwater Fish‎ > ‎Betta‎ > ‎

Betta rutilan


Betta rutilan
Fire Betta
火焰斗鱼
Betta rutilans is included in the Betta coccina group/complex of closely-related Betta species. At time of writing this assemblage also includes B. brownorum , B. burdigala , B. livida , B. miniopinna, B. persephone , B. tussyae and of course B. coccina . These are all small fish and with the exceptions of B. persephone and B. miniopinna are predominantly red in colour. Identifying some of the red ones correctly is not always easy as the patterning in them can be both similar and confusingly variable. Betta rutilans is relatively easy to distinguish as it lacks the iridescent blue/green blotch found on the flank in most of the other species and the tips of the ventral fins are always white. In a 1991 paper discussing various Western Indonesian freshwater species Kottelat described some of the distinguishing characteristics of the species as follows: 

"Betta rutilans shares with Betta tussyae, a modal dorsal ray count of 12 (vs. 10 and 11 in other species of the complex), a modal subdorsal scale count of 9 (vs. 7), a greater length of dorsal base (20-23% SL, vs. 14-19), absence of a midlateral blotch (vs. usually present in male Betta coccina and Betta sp. Witte & Schmidt, submitted) and white pelvic filament (vs. black in Betta coccina ). Betta rutilans differs from Betta tussyae by a lower mode in dorsal (I, vs. II) and anal spines (II, vs. III), smaller size (up to 25 mm SL, vs. 48, aquarium specimens), and absence of bluish green spots on proximal areas of unpaired fins (vs. usually present)." 

Rutilans is usually solid red but some individuals will have green sides.
Comments