Does the limpet Patella cochlear fertilize its own algal garden
Does the limpet Patella cochlear fertilize its own algal garden
复制标题
帽贝髌骨蜗是否给自己的藻园施肥
DOI：
10.3354/meps194113
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发表时间：
2000
影响因子：
2.5
通讯作者：
G. Branch
中科院分区：
文献类型：
--
作者：
É. Plagányi;G. Branch
海洋食草动物的藻类“园艺”已经被描述为几种物种，但食草动物通过增强营养来影响其花园的可能性受到的关注较少。本研究检验了领土潮间带帽贝的营养物质再生提高其藻园生产力的假设。采用(1)低潮时测定帽贝壳下尿素和铵的浓度，定量测定耳蜗的氮排泄；(2)进行实验室实验，监测帽贝存在时尿素、铵和硝酸盐浓度的变化；(3)利用同位素稀释技术在野外试验中获得帽贝排泄和藻类吸收速率的直接估计。在低潮暴露期间，氮以尿素和铵的形式排泄（尿素：1.15 pmol ml -1；铵：0.07 pmol ml -1）积聚在耳蜗蜗壳下，与周围的藻园密切接触。30 mm帽贝的平均氨排泄量为458.9 μg NH 4 -N d -1，与海藻园的氮生长需水量（427.8 μg n -生长园-1 d -1）相似。在一个实验室内，根据藻类吸收15个氮的情况估计了藻类的吸收速率，表明耳蜗藻排泄的铵提供了藻类园每日氮生长需求的大约30%。此外，藻类显示出“激增”吸收的潜力，这种适应将使它们能够利用含氮排泄物，然后在这些排泄物被野外的水运动消散。我们的研究结果表明，耳蜗藻和潜在的其他海洋园艺物种可以通过限制营养物质的再生来提高藻类花园的生产力。
Algal 'gardening' by marine grazers has been described for several species but the possibility that grazers influence their gardens through nutrient enhancement has received less attention. This study examined the hypothesis that nutrient regeneration by the territorial intertidal limpet Patella cochlear enhances the productivity of its algal gardens. Nitrogenous excretions by P. cochlear were quantified by (1) measuring urea and ammonium concentrations under limpet shells at low tide; (2) conducting a laboratory experiment to monitor changes in urea, ammonium and nitrate concentrations in the presence of limpets; and (3) using an isotope dilution technique in a field experiment to obtain direct estimates of limpet excretion and algal uptake rates. During low-tide exposure, nitrogenous excretions in the form of urea and ammonium (urea: 1.15 pmol ml -1 ; ammonium: 0.07 pmol ml -1 ) accumulated under P. cochlear shells, in close contact with the surrounding algal garden. The average quantity of ammonium excreted by a 30 mm limpet was estimated as 458.9 μg NH 4 -N d -1 , which is similar to the estimated nitrogen growth requirements of an algal garden (427.8 μg N-growth garden -1 d -1 ). Algal uptake rates, estimated in an experimental chamber on the basis of 15 N incorporation by the algae, indicated that ammonium excretions by P. cochlear supplied approximately 30 % of the algal garden's daily nitrogen growth requirements. Moreover, the algae demonstrated a potential for 'surge' uptake, an adaptation which would enable them to exploit nitrogenous excretions before these are dissipated by water movement in the field. Our findings show that P. cochlear, and potentially other marine gardening species, can enhance the productivity of their algal gardens through the regeneration of limiting nutrients.