2.2. Larval growth experiment
A growth experimentwas performed using tilapia at late larval stage.
Eight weeks after placing the parental generation in the broodstock
tanks, about 1000 larvae were collected from each tank and graded
according to size. Out of each batch, 120 larvae of similar size were selected
for use. The average body weight and average body length were
23 ± 4 mg and 10.3 ± 0.8 mm, and 20 ± 4 mg and 10.0 ± 0.8 mm for
the larvae from the control tank and the BFT tank, respectively (further
called “origin of the larvae”). The larvae were subsequently randomly
distributed in 2 L plastic tank, previously filled with 1.5 L of water
from either the BFT tank or the control tank (further called “culture
water”) at a density of 15 fish/tank (10 fish/L). Feeding was performed
using a commercial feed (40% protein) (PT. Matahari Sakti, Indonesia)
at a level of 40% on the initial fish biomass per day, spread over 4
times a day. For the tanks containing BFT water, molasses (53% C) was
added daily at an estimated C/N ratio of 10. Artificial light was provided