The reproduction viability of Indonesian endemic fishOryzias marmoratus(Aurich, 1935) fed bySpirulina

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.

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

“…Based on these data, it is assumed that the use of Spirulina in feed can increase feed efficiency of M. ajamaruensis. In line to results of [14,21,22,23,24] that Poecilia reticulata, Carassius auratus, Clarias gariepinus and Oryzias marmoratus fed a diet with a higher Spirulina content had a good effect on the value of feed conversion and on growth rate. Broodstock size in C treatment was relatively almost the same size of B treatment and A.…”

“…Based on these informations, it shows that the use of Spirulina has been able to increase its growth performance, survival rate, progeny production and fish skin coloration. Similarly, [22] reported that the use of Spirulina 6% has been able to improve the HR and SR7 values in O. marmoratus.…”

“…It is presumed that the mineral content of Spirulina affects the embryogenesis process of the fish, and it is also suggested that the content of 3% Spirulina provides an optimal effect on the hatching process of M.ajamaruensis. Meanwhile, [22] reported that the addition of Spirulina to the feed has slightly prolonged the EIT value of O marmoratus. Eggs from broodstock fed a diet containing 6% Spirulina had a longer EIT value than those fed 3% and without Spirulina.…”

“…Research on the effect of Spirulina on the reproduction of the endemic fish M ajamaruensis has not been reported. It is suggested that the addition of Spirulina on feed will be able to affect on the reproductive patterns of this fish like on the reproduction viability of the endemic fish such as on the endemic fish Oryzias marmoratus [22].…”

Adaptation performance of immature broodstock Oryzias woworae post-transportation of closed system

“…The unfertilized eggs of O. woworae showed that several broodstocks were not ready to spawn due to several factors, both external (water quality) and internal (fish nutrition). Several factors affect fish reproductive performance, such as water quality, adequate nutrition, and the age of ready fish to spawn [13].…”