Subject:
behavioral stress response; eye color pattern; Oreochromis niloticus; seed productionTags (serials)
Author/s: Vera Cruz, Emmanuel M.; Jimenez, Eddie Boy T.; Apongol-Ruiz, Bethzaida M.
PR-AS
2020
TPJF V27N2
SEARCA Library
Serials
The Philippine Journal of Fisheries
Department of Agriculture, National Fisheries Research and Development Institute (DA-NFRDI)
Jul-Dec 2020
Quezon City, Philippines
This experiment assessed the effect of breederâÂÂs behavioral stress response [i.e., eye color pattern (ECP)] during isolation on O. niloticus seed production. ECP change was marked by fractional color changes of the iris and sclera, which was transformed into scores ranging from 0 (no darkening) to 8 (total darkening). After isolation, breeders were divided into two social groups: proactive breeders (PB) were those with a mean ECP score of <2, and reactive breeders (RB) with a mean ECP score of >6. Two breeding cycles were done in six (1 m x 2 m x 1 m) net enclosures. Mean spawning rates (SR) in PB during the two cycles were 38.89ñ14.70% and 33.33ñ8.87% while 3.33ñ9.62% and 22.22ñ2.48% in the RB group. Total seed productions (TSP) in PB were 1,906.22ñ733.72 and 1,681.19ñ1,070.48 fry, and those in RB were 996.35ñ218.11 and 461.39ñ151.37 fry. There were no significant differences between the two groups on SR and TSP in both cycles. On seed production per female that spawned, however, significantly (P<0.05) higher means (796.33ñ77.68 and 726.33ñ124.08 fry) were observed in the PB compared to those in RB (522.73ñ54.68 and 335.83ñ44.98 fry). These results demonstrated that seed production in O. niloticus could be increased by selecting proactive breeders through the evaluation of their ECP during isolation.
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