Reproduction pattern on Melanotaenia ajamaruensis (Allen & Cross 1980) the endemic rainbowfish of Lake Ajamaru Papua, Indonesia fed by Spirulina

Melanotaenia ajamaruensis with the common name Ajamaru Rainbowfish belongs to Rainbowfish group that endemic of Lake Ajamaru Papua, Indonesia. These fish are very potential as ornamental fish, but the biological information is very rare. The fish has just domesticated, therefore a research to inceased the reproductive factors in captivity is needed. The research of reproduction ability was conducted by using various levels of Spirulina in feed (A=0; B=3, and C=6%) during 40 days (September-October 2020) at the RC for Limnology-Indonesian Institute of Sciences Laboratory. Fish rearing used an aquarium sized. of 45x45x40 cm with two replications and the analysis was carried out descriptively. Treatment C (feed 6% Spirulina ) had advantages in total eggs (220 eggs), number of eggs per female (110 eggs/female), total number of larvae (214 larvae), number of larvae per female (107 larvae/female), survival rate 7-day and 15-day of larvae were 96.502±8.414% and 91.829±14.030%, respectively. Treatment B (3% Spirulina ) had advantages in spawning frequency (12 times), fertilization rate/FR (100%), hatching rate/HR (100%) and shortest egg incubation time (5,916±1,676 days). Spirulina was able to increase the reproductive ability of the endemic fish M ajamaruensis in a captivity conditions. Further research of this fish is still needed.