Institut de Ciències del Mar (ICM-CSIC), Pg. Marítim de la Barceloneta 37-49, 08003, Barcelona, Catalonia, Spain.
Institut de Ciències del Mar (ICM-CSIC), Pg. Marítim de la Barceloneta 37-49, 08003, Barcelona, Catalonia, Spain.
Mar Environ Res. 2023 Apr;186:105940. doi: 10.1016/j.marenvres.2023.105940. Epub 2023 Mar 4.
We assessed the effects of nutrient imbalanced diets on the feeding, reproduction and gross-growth efficiency of egg production of the copepod Paracartia grani. The cryptophyte Rhodomonas salina, cultivated under balanced (f/2) and imbalanced growth conditions (N and P limitation), served as prey. Copepod C:N and C:P ratios increased in the imbalanced treatments, particularly under P limitation. Feeding and egg production rates did not differ between the balanced and N-limited treatments but decreased under P limitation. We found no evidence of compensatory feeding in P. grani. C gross-growth efficiency averaged 0.34 in the balanced treatment and declined to values of 0.23 and 0.14 for the N- and P-limited treatments, respectively. Under N limitation, N gross-growth efficiency increased significantly to a mean value of 0.69, likely as a result of increasing the nutrient absorption efficiency. P gross-growth efficiency reached values > 1 under P limitation, involving the depletion of body P. Hatching success was >80%, with no differences among diets. Hatched nauplii, however, had lower size and slower development when the progenitor was fed a P-limited diet. This study highlights the effects of P limitation in copepods, which are more constraining than N, and the presence of maternal effects driven by prey nutritional composition that ultimately may affect population fitness.
我们评估了营养失衡饮食对产孵桡足类 Paracartia grani 的摄食、繁殖和总生长效率的影响。作为猎物，培养了在平衡（f/2）和失衡生长条件（氮和磷限制）下的 cryptophyte Rhodomonas salina。在失衡处理中，桡足类的 C:N 和 C:P 比值增加，特别是在磷限制下。摄食率和产卵率在平衡和氮限制处理之间没有差异，但在磷限制下下降。我们没有发现 P. grani 存在补偿性摄食的证据。在平衡处理中，C 总生长效率平均为 0.34，而在氮限制和磷限制处理中分别下降到 0.23 和 0.14。在氮限制下，N 总生长效率显著增加到平均 0.69，可能是由于吸收效率的提高。在磷限制下，P 总生长效率达到 >1 的值，涉及到体内磷的耗尽。孵化成功率>80%，不同饮食之间没有差异。然而，当亲代喂食磷限制饮食时，孵化的无节幼体体型较小，发育较慢。本研究强调了磷限制对桡足类的影响，磷限制比氮限制更具约束性，以及由猎物营养组成驱动的母体效应的存在，最终可能影响种群适应性。
