Pawat Tangvuthipong. Effects of 5-hydroxytryptamine on larval development of the giant freshwater prawn, macrobrachium rosenbergii . Master's Degree(Environmental Biology). Mahidol University. : Mahidol University, 2004.
Effects of 5-hydroxytryptamine on larval development of the giant freshwater prawn, macrobrachium rosenbergii
Abstract:
This work studied the effect of 5-hydroxytryptamine (5-HT or serotonin) on larval
development of the giant freshwater prawn, Macrobrachium rosenbergii. Day 4 posthatch
larvae were treated with different concentrations of 5-HT, 5, 50, and 100 μg/ml
in 15 parts per thousand commercial seawater for periods of 2 or 9 days. Day 25
post-hatch larvae from those treated with 50 μg/ml 5-HT for 2 days showed
significantly higher survival rate than other groups (p<0.05). While all larvae treated
with 50 and 100 μg/ml 5-HT continuously for 9 days died by day 13 post-hatch.
Besides, 5-HT caused pigmentation within 1 h after treatment. Larvae showed redorange
color on their eyestalks, cephalothoraxes, and abdomens. The 100 μg/ml 5-
HT treated group showed the strongest pigmentation, while the non-treated larvae
did not show any color change. Moreover, the effect of 5-HT on larvae seemed to be
dose-dependent not only in causing pigmentation but also in enhancing growth and
developmental rate. The body length of larvae increased significantly in the treated
groups and transformation of the larvae to post-larvae occurred sooner in the treated
groups than those of the control. The average body length of the 100 μg/ml 5-HT
treated larvae was 4.1+0.99 mm while that of the control was 2.2+0.42 mm. And the
transformation day of the 100 μg/ml 5-HT treated larvae was day 30 post-hatch
while the transformation day of the control was day 40 post-hatch