TABLE OF CONTENTS Pages Symposium 1 - the National Sea ...

In experiment 2, Pistia stratiotes grew fastest in terms of total wet matter, but almost
same growth with Hygrophila angustifolia in dry matter. Eichhornia crassipes, and
Hydrocotyle leucocephala showed much inferior growth both in wet and dry matter among
them (Table 2). The total weights increased 11.2, 7.4, 6.4, and 4.2 times initial biomass in 30
days, respectively.
Table 1. Absorption of inorganic nitrogen from the water by four aquatic plants in the
aquarium in experiment 1 (30.1-38.5°C). The water was brought from an
existing IBK system fish farm. (unit: mg/L in water).
Aquatic Plants NH4-N NO2 - N NO3 - N
Initial 24h 48h Initial 24h 48h Initial 24h 48h
Pistia stratiotes 2.3 1.1 0.4 0.197 0.029 0.024 21.4 20.1 17.4
Hygrophila angustifolia 2.3 1.7 1.6 0.197 0.170 0.15 21.4 20.1 20.1
Eichhornia crassipes 2.3 1.4 0.6 0.197 0.057 0.029 21.4 20.8 17.9
Hydrocotyle leucocephala 2.3 1.7 2.3 0.197 2.91 7.8 21.4 28.4 62.8
Table 2. The growth performance of four aquatic plants at the top of filter bed of the IBK
system for 30 days and proximate analysis of the plants in experiment 2.
Item Pistia stratiotes
3
Hygrophila
angustifolia
Eichhornia
crassipes
Hydrocotyle
leucocephala
Initial biomass (g) 2,000 2,000 2,000 2,000
Final biomass (g) 22,376 12,774 14,805 8,482
Final/Initial ratio 11.2 6.4 7.4 4.2
Biomass produced (g) 20,376 10,774 12,805 6,482
Moisture (%) 90.00 80.20 92.30 89.20
Dry Matter (DM) (%) 10.00 19.80 7.70 10.80
Biomass produced, DM (g) 2,038 2,133 986 700
Crude protein in DM (%) 4.61 2.62 4.75 4.85
Crude protein in WM (%) 0.46 0.52 0.37 0.52
Crude protein (g) 93.93 55.89 46.83 33.95
Nitrogen value (g) 15.03 8.94 7.49 5.43
Crude fat in DM (%) 22.44 15.40 15.48 22.86
Crude fat in WM (%) 2.24 3.05 1.19 2.47
Crude fat (g) 457.24 328.52 152.63 160.03
Crude ash in DM (%) 24.18 12.71 18.1 17.99
Crude ash in WM (%) 2.42 2.52 1.39 1.94
Crude ash (g) 492.69 271.14 178.46 125.94
DM: dry matter; WM: wet matter
In terms of total nitrogen (N) synthesized by the plants on an area of 2 m 2 for 30 days,
Pistia stratiotes, with an amount of 15.03 g, was considerably superior to the other 3 plants,
Hygrophila angustifolia (8.9 g), Eichhornia crassipes (7.49 g), and Hydrocotyle leucocephala
(5.43 g). Thus the fastest growth rate of Pistia stratiotes in experiment 2 well agrees with the