碳酸氢铵对龙须菜(Gracilaria lemaneaformis)污损生物多棘麦杆虫(Caprella acanthogaster)的防除效果

Removal of the Biofouling Organism Caprella acanthogaster Attached on Cultivated Seaweed Gracilaria lemaneaformis Using Ammonium Bicarbonate

中文关键词: 多棘麦杆虫  防除效果  碳酸氢铵  龙须菜

英文关键词: Caprella acanthogaster  Antifouling efficiency  Ammonium bicarbonate  Gracilaria lemaneaformis

中文摘要:

      2012年夏季在爱莲湾，对采用碳酸氢铵防除养殖龙须菜(Gracilaria lemaneaformis)上的污损生物多棘麦秆虫(Caprella acanthogaster)的效果进行了研究，探讨了碳酸氢铵浓度及处理时间对多棘麦秆虫脱落率和死亡率的影响。实验的3个处理时间分别为5、10、15 min，碳酸氢铵浓度分别为0.5、0.6、0.7、0.8、0.9、1.0、2.0、3.0、4.0、5.0 g/L。结果表明，碳酸氢铵浓度、处理时间对多棘麦杆虫脱落率或死亡率均有显著影响(P < 0.05)。随着浓度的升高、处理时间的延长，多棘麦杆虫脱落率及死亡率都呈逐渐增加的趋势。多棘麦杆虫脱落率(D)或死亡率(M)与浓度(C)之间的关系均符合S型曲线模型lnD = a + (b/C)或lnM = c (d / C)。在5、10、15 min时，碳酸氢铵对麦杆虫的致死浓度分别为7.36、6.17、3.68 g/L，对应的非离子氨浓度分别为37.72、21.32、14.25 mg/L。

英文摘要:

      Biofouler Caprella acanthogaster, a subtype of Crustacea Amphipoda, feed on cultivated macroalgae Gracilaria lemaneaformis and resultantly affect the survival and growth of the latter. Ammonia could be a potential antifoulant to biofouler C. acanthogaster due to its toxic effects at high concentrations. NH4HCO3 may be an efficient source of the ammonia-based antifoulant——as a common agricultural fertilizer, it could provide nitrogen nutrient for G. lemaneiformis; moreover, it is readily to be reduced into water and carbon dioxide. In our experiments, C. acanthogaster was exposed to NH4HCO3 solution at different concentrations (C) including 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 2.0, 3.0, 4.0 and 5.0 g/L, with 0 g/L as the blank control. The detachment rate (D) and mortality rate (M) of C. acanthogaster was measured after three treatments separately——short time (5 min), medium time (10 min), and long time (15 min). The results showed that both the NH4HCO3 concentration and the length of treatment had significant effects on the detachment rate (D) and the mortality rate (M) (P<0.05). The saturating lethal concentrations of NH4HCO3 for the 5 min, 10 min and 15 min treatments were 7.36 (7.007.81), 6.17 (5.566.99), and 3.68 (2.905.61) g/L, respectively. D and M increased along with the elevation of the NH4HCO3 concentration and the exposure time. In the same exposure time, the relationship between D or M and the NH4HCO3 concentration could fit in the S-shaped curve equation：ln D = a + (b/C), or ln M = c (d/C). Given that C. acanthogaster has a short reproduction time that short-term operation is more plausible in aquaculture, we suggested that G. lemaneaformis should be soaked in 7.36 g/L NH4HCO3 solution for 5 min. However, more caution should be exercised when NH4HCO3 is applied in eutrophication areas.