Effect of various live food organisms on growth and survival of hatchery-bred Philippine silver therapon larvae, Leiopotherapon plumbeus (Kner, 1864)

• Main Author: Anano, Julie Andrea P.
• Format: text
• Language: English
• Published: Animo Repository 2016
• Subjects: Biology
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/5041
• Institution: De La Salle University

Philippine silver therapon, Leiopotherapon plumbeus, locally known as ayungin, is an endemic fish species in the country. The demand for silver therapon remain high despite the decline of its population and commercial catches. Taking into account the potential of this species for stock enhancement, this study focused on developing an indoor rearing protocol necessary to provide potential L. plumbeus juveniles for aquaculture. Experiments were conducted into two phases: (1) a 10-day feeding experiment which used different feeding schemes where live food organisms [Brachionus (B), Moina (M), co-fed with BM, Chlorella (C) and filtered lake water (L)] are administered and (2) a 22-day indoor rearing period which adopted the most ideal feeding scheme (BM) obtained from the first feeding experiment. Resorption rate of yolk was determined based on the changes in the yolk-sac volume at specific time intervals (hours after hatching, HAH). Morphometric measurements were evaluated to assess growth performance among different feeding schemes (P < 0.05). Survival rate was determined at the end of each feeding experiment [9 and 22 days after hatching (DAH)]. Rapid absorption of yolk by larvae was denoted within 24 HAH, with about 89.5% of the initial yolk volume reduced. Growth parameters of L. plumbeus larvae reared under different feeding schemes showed significant differences starting at 5 DAH (P < 0.05) onward. After a total of 10 days for the first feeding experiment, a significant decline in fish larval samples were observed under two feeding schemes (C and L). BM has a significant higher rate of survival (18.07 ± 7.09%) compared to other treatments. At 22 DAH, a low survival rate of 1.95 ± 0.34% was recorded for BM. Chlorella-enriched zooplankton must be available before the onset of exogenous feeding (2 DAH). Brachionus rotundiformis (15-20 mL-1) can be considered as a starter food for silver therapon larviculture and Moina micrura (5-10 mL-1) can be utilized during an assumed co-feeding phase at 6 DAH.