Osmoregulation, nutritional effects and buoyancy of marine larval fish: a bioassay for assessing density changes during the earliest life-history stages
Osmoregulation, nutritional effects and buoyancy of marine larval fish: a bioassay for assessing density changes during the earliest life-history stages
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海洋幼鱼的渗透调节、营养效应和浮力：评估最早生命史阶段密度变化的生物测定
DOI：
10.1007/s002270050139
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发表时间：
1997
期刊：
影响因子：
2.4
通讯作者：
W. C. Leggett
中科院分区：
文献类型：
--
作者：
M. Sclafani;G. Stirling;W. C. Leggett
摘要有人假设，处于饥饿晚期的海洋鱼类幼鱼会因光合调节失效而失水，从而导致密度增加（ρ =质量体积-1）。幼虫浮力的变化目前归因于鱼鳔调节和蛋白质合成或catalysts。与渗透调节有关的密度变化是另一种机制，其重要性尚未在实验室中得到检验，其对垂直分布的影响也是未知的。我们提供的证据表明，渗透控制的损失是一个合理的机制，增加密度的幼鳕鱼（鳕morhua L.）。此外，我们的研究结果表明，这一机制并不限于幼虫在饥饿的高级阶段。"相对"幼虫密度估计使用修改的密度梯度。我们使用重量分析法将营养的影响与代谢调节失败分开。我们评估了抽样层对估计幼虫密度的重要性。在三个深度层（分层样品）的比例抽样产生的偏差最小的方法，用于确定在实验室培养的幼虫种群的“平均”密度。从培养罐底部三分之一取样的幼虫比从表面取样的幼虫密度大得多。所有年龄段的幼虫都是如此。从孵化到饥饿死亡，表层幼虫的平均密度变化很小（Δ ρ = 5.0 × 10 − 4 g cm − 3），而底层幼虫的密度变化很大（Δ ρ = 3.8 × 10 − 3 g cm − 3）。这些大的密度差异表明，从底层采样的幼虫要么是adheritically强调或facultimate通过调节途径改变其密度。初步观察表明，在靠近底部取样的幼虫中，生命力较低。从表层取样的幼虫的平均密度的微小变化是由于饥饿。我们观察到的“饥饿应激”和“饥饿”幼虫之间的密度差异很容易被误解为个体幼虫在摄食和生长方面的差异。潜在的偏差增加的密度，从浮游生物调控失败必须考虑作为一个因素，在实验设计开发，以评估的影响，美联储和饥饿的治疗浮力的幼虫的所有年龄。我们描述的简单的生物测定可能被证明是有用的，作为一种手段，评估幼虫的条件，并作为一种机制，用于评估影响幼虫的垂直分布在该领域的因素。
Abstract It has been hypothesized that marine fish larvae in the advanced stages of starvation would show increased density (ρ = mass volume−1) from water loss due to osmoregulation failure. Changes in larval buoyancy are currently attributed to swim bladder regulation and protein synthesis or catabolism. Osmoregulation-related changes in density is an alternative mechanism, the importance of which remains untested in the laboratory and the influence of which on vertical distributions is unknown. We provide evidence that loss of osmotic control is a plausible mechanism for increased density of larval cod (Gadus morhua L.). Furthermore, our results show that this mechanism is not restricted to larvae in the advanced stages of starvation. “Relative” larval densities are estimated using a modified density gradient. We use a gravimetric method to separate the effects of nutrition from osmoregulation failure. We assessed the importance of sampling strata on estimates of larval density. Proportional sampling within three depth strata (stratified sample) produced the least biased method for determining the “average” density of a population of larvae in laboratory culture. Larvae sampled from the bottom third of the culture tank were significantly more dense then those sampled from the surface. This was true for larvae of all ages. The average change in density from hatching till death from starvation for larvae sampled in the surface stratum was nominal (Δρ = 5.0 × 10−4 g cm−3), while the change for those sampled from the bottom stratum was large (Δρ = 3.8 × 10−3 g cm−3). These large density differences suggest that larvae sampled from the bottom stratum were either osmotically stressed or were facultatively changing their density via regulatory pathways. Preliminary observations suggest that vitality is lower amongst those larvae which are sampled near the bottom. The small change in average density of larvae sampled from the surface stratum was due to starvation. The density differences we observed between “osmotically stressed” and “starving” larvae could readily have been misconstrued as differences in feeding and growth experienced by individual larvae. The potential bias of increased density from osmoregulation failure must be considered as a factor in experimental designs developed to assess the effect of fed and starved treatments on buoyancy for larvae of all ages. The simple bioassay we describe may prove useful both as a means of assessing larval condition and as a mechanism for evaluating factors affecting larval vertical distributions in the field.
论20世纪40年代首尔市中心小公园规划中南大门公园的变迁特征
DOI：
--
发表时间：
2019
期刊：
影响因子：
--
作者：
石田 潤一郎;安 箱敏;砂本 文彦;金 珠也;中川 理;坊城俊成・坊城ガブリエラ知子;永井康雄,濱 定史;山田由香里・藤田謙一・繁宮悠介・田中翔大;安箱敏;安箱敏，石田潤一郎
通讯作者：
安箱敏，石田潤一郎