Table 1.

Effects of thiourea treatment on tilapia juveniles

0 p.p.m.300 p.p.m.600 p.p.m.900 p.p.m.
Total length (mm)13.7±1.1a11.3±0.5b10.7±0.4c10.4±0.4c
Wet mass (mg)35.1±11.0a16.4±2.6b12.9±1.4bc10.9±1.6c
Mortality (%)013.650.844.1
Otolith growth
   Core to TC (μm)127.4±10.3a127.8±8.5a128.8±5.9a127.1±7.2a
   TC to edge (μm)80.5±27.2a45.4±6.1b34.8±6.9c33.2±4.8c
   Newly deposited DGI13.0±1.3a11.0±0.9b9.0±0.9c9.2±1.1c
  • Fish were immersed in different concentrations of thiourea (TU, p.p.m.) from 15 to 27 days post-hatching (d.p.h.) and were then killed for measurement on 28 d.p.h. Data are shown as means ± s.d. (N=15–18). TC, tetracycline mark; DGI, daily growth increment. Values with different superscript letters are significantly different (P<0.05)