Page 208 - 《水产学报》2025年第6期

潘恒丰，等 水产学报, 2025, 49(6): 069617

Effects of duckweed (Lemna minor) biomass on epiphytic diatom
colonization under aeration disturbance

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PAN Hengfeng , WANG Xiaodong , CHE Xuan , WANG Hong ,
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LI Yiming , CHENG Xiangyu , LIU Xingguo 1
1. Fishery Machinery and Instrument Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200092, China;
2. Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education,
Shanghai Ocean University, Shanghai 201306, China;
3. Key Laboratory of Inland Saline-alkaline Aquaculture, Ministry of Agriculture and Rural Affairs,
Engineering Technology Research Center of Saline-alkaline Water Fisheries, East China Sea Fisheries Research Institute,
Chinese Academy of Fishery Sciences, Shanghai 200090, China

Abstract: Diatoms (Bacillariophyta) have important biological significance and application value. Diatoms are important
primary producers in water bodies and can serve as bait for many fish, shellfish, and other aquatic animals, thus playing a cru-
cial role in aquatic ecosystems, particularly in aquaculture. The high-density cultivation of diatoms, particularly epiphytic spe-
cies, represents a critical research frontier in aquaculture. However, there is currently limited research on using natural aquatic
plants to cultivate epiphytic diatoms. In order to cultivate epiphytic diatoms with Lemna minor, a culture experiment was con-
ducted with decaying L. minor in different biomass under aeration disturbance. According to the wet biomass gradient of the
rotting L. minor, a total of 5 treatments were set as 0, 4, 8, 12 and 14 g/L, named as treatment Ⅰ, Ⅱ, Ⅲ, Ⅳ and Ⅴ from low to
high, respectively, each with 3 replicates. The results showed that no hypoxia occurred in any of the treatments. The concentra-
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tions of ammonia nitrogen (NH 4 -N) and soluble reactive phosphorus (SRP) in treatment Ⅰ [(0.584±0.649) and (0.336±0.274)
mg/L, respectively] were significantly higher than those in the other treatments (P<0.05). The dissolved total nitrogen (DTN)
and dissolved total phosphorus (DTP) concentrations in all treatments exhibited a declining trend before stabilizing, with no
significant differences observed between treatments. Although treatment V had the highest mean DTN [(1.665±1.678) mg/L]
and DTP [(0.603±0.672) mg/L] concentrations, these values were not statistically significant. In the middle and late stages of
the experiment, diatoms of Navicula and Cocconeis appeared on the rotting L. minor, and the wet weight of the epiphytic diat-
oms of treatment Ⅳ was the highest (P<0.05), reaching the maximum of 249.13 mg/L on the 35th day. The maximum biomass
of epiphytic diatoms on L. minor was significantly higher than that on glass sheetS (P<0.05). The results show that the wet bio-
mass of rotting L. minor at 12 g/L is more conducive to the growth of epiphytic diatoms under aeration disturbance, and L.
minor are more beneficial to the growth of epiphytic diatoms than glass sheet. The rotting L. minor releases nutrients such as
nitrogen and phosphorus, providing a material basis for the growth of diatoms and serving as a medium for the diatoms’ attach-
ment growth. This experiment provides a feasible method for cultivating epiphytic diatoms in a decaying state of L. minor
under aeration disturbance, expanding the cultivation method of epiphytic diatoms.
Key words: Lemna minor; epiphytic diatoms; aeration disturbance; nutrients
Corresponding author: WANG Xiaodong. E-mail: wangxiaodong@fmiri.ac.cn
Funding projects: National Freshwater Genetic Resource Center (FGRC: 18537); National Key Research and Development
Program of China (2019YFD0900305); Central Public-interest Scientific Institution Basal Research Fund, CAFS (2023TD67)

https://www.china-fishery.cn 中国水产学会主办 sponsored by China Society of Fisheries
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