The reproduction viability of Indonesian endemic fish Oryzias marmoratus (Aurich, 1935) fed by Spirulina

Abstract

Oryzias marmoratus is one of the ornamental aquarium fish species that live endemic to Towuti Lake, South of Sulawesi, Indonesia. However, the fish has been categorized as near threatened by IUCN. A current report showed the fish could be cultivated. This research aims to improve the reproduction quality in cultivation by using artificial feed containing Spirulina (A=0, B=3, and C=6) % dry weight. The study was conducted with two replications using an aquarium (80 x 40 x 40 cm) for 40 days (October-December 2020) at Research Center for Limnology-LIPI. Each aquarium contains 21 broodstock (female: male = 2:1). Observation parameters are the total number of spawning/ToS (time), ovulated eggs number/OEN, fertilization ability/FA (%), hatching ability/HA (%), number of larvae/NoL, the egg of incubation time/EIT (day), survival of larvae seven days old after hatching/SR7 (%). Based on descriptive analysis, the use of feed C (containing 6% Spirulina) produced the highest values of ToS, OEN, %HA, NoL, and SR7 (%) were ten times; 89 eggs; 89 larvae, 100%; and 98.89±3.51% respectively. Spirulina could increase the reproduction viability and is presumed to enhance feed efficiency of Oryzias marmoratus, but the optimum levels have not been obtained.