Frangoulis C, Christou E D, Hecq J H
Hellenic Centre for Marine Research, Institute of Oceanography, Anavissos 19013, Attiki, Greece.
Adv Mar Biol. 2005;47:253-309. doi: 10.1016/S0065-2881(04)47004-7.
We compare the nature of copepod outfluxes of nonliving matter, the factors controlling their rate and their fate, and finally their role, particularly their relative importance in the carbon and nitrogen cycle. Copepods release dissolved matter through excretion and respiration and particulate matter through production of faecal pellets, carcasses, moults, and dead eggs. Excretion liberates several organic C, N, and P compounds and inorganic N and P compounds, with inorganic compounds constituting the larger part. The faecal pellets of copepods are covered by a peritrophic membrane and have a highly variable size and content. There is less information on the nature of other copepod particulate products. The weight-specific rates of posthatch mortality, respiration, excretion, and faecal pellet production have similar C or N levels and are higher than those of moulting and egg mortality. In general, most important factors controlling these rates are temperature, body mass, food concentration, food quality, and faunistic composition. Physical and biological factors govern the vertical fate of copepod products by affecting their sedimentation speed and concentration gradient. The physical factors are sinking speed, advection, stratification, turbulent diffusion, and molecular diffusion. They influence the sedimentation speed and degradation of the copepod products. The biological factors are production, biodegradation (by zooplankton, nekton, and microorganisms) and vertical migration of copepods (diel or seasonal). Physical degradation and biodegradation by zooplankton and nekton are faster than biodegradation by microorganisms. The most important copepod outfluxes are excretion and faecal pellet production. Excretion offers inorganic nutrients that can be directly used by primary producers. Faecal pellets have a more important role in the vertical transport of elements than the other particulate products. Most investigation has focused on carbon burial in the form of copepod faecal pellets, measured by sediment traps, and on the role of ammonia excretion in nutrient recycling. Full evaluation of the role of copepod products in the transport and recycling of elements and compounds requires a quantification of all copepod products and their different fates, particularly detritiphagy, remineralization, and integration as marine snow.
我们比较了桡足类非生物物质外流的性质、控制其速率和归宿的因素，以及它们的作用，特别是它们在碳和氮循环中的相对重要性。桡足类通过排泄和呼吸释放溶解物质，通过产生粪便颗粒、尸体、蜕皮和死卵释放颗粒物质。排泄释放出几种有机碳、氮和磷化合物以及无机氮和磷化合物，其中无机化合物占较大比例。桡足类的粪便颗粒被围食膜覆盖，大小和成分变化很大。关于其他桡足类颗粒产物的性质，信息较少。孵化后死亡率、呼吸、排泄和粪便颗粒产生的重量比速率具有相似的碳或氮水平，且高于蜕皮和卵死亡率。一般来说，控制这些速率的最重要因素是温度、体重、食物浓度、食物质量和动物群落组成。物理和生物因素通过影响桡足类产物的沉降速度和浓度梯度来控制其垂直归宿。物理因素包括下沉速度、平流、分层、湍流扩散和分子扩散。它们影响桡足类产物的沉降速度和降解。生物因素包括生产、生物降解（由浮游动物、游泳生物和微生物进行）以及桡足类的垂直迁移（昼夜或季节性）。浮游动物和游泳生物的物理降解和生物降解比微生物的生物降解更快。最重要的桡足类外流是排泄和粪便颗粒产生。排泄提供了可被初级生产者直接利用的无机养分。粪便颗粒在元素的垂直运输中比其他颗粒产物发挥着更重要的作用。大多数研究集中在通过沉积物捕获器测量的以桡足类粪便颗粒形式的碳埋藏，以及氨排泄在营养物质循环中的作用。要全面评估桡足类产物在元素和化合物的运输和循环中的作用，需要对所有桡足类产物及其不同归宿进行量化，特别是碎屑摄食、再矿化以及作为海雪的整合。
