Individual-based model of larval transport to coral reefs in turbulent, wave-driven flow: behavioral responses to dissolved settlement inducer
Individual-based model of larval transport to coral reefs in turbulent, wave-driven flow: behavioral responses to dissolved settlement inducer
复制标题
基于个体的幼虫在湍流、波浪驱动流中运输到珊瑚礁的模型：对溶解沉降诱导剂的行为反应
DOI：
10.3354/meps335001
复制
发表时间：
2007
影响因子：
2.5
通讯作者：
M. Hadfield
中科院分区：
文献类型：
--
作者：
M. Koehl;JA Strother;M. Reidenbach;JR Koseff;M. Hadfield
许多底栖海洋动物的幼虫会根据水中的化学信号沉降并变态。在许多浅海沿岸栖息地所具有的湍流和波浪驱动的水流中，水体中微小幼虫对溶解化学信号的行为反应是否会影响它们向基质的输送呢？我们利用一种基于个体的海蛞蝓（Phestilla sibogae）幼虫模型来解决这个问题，这些幼虫在珊瑚礁上方的振荡水流中被输送。Phestilla sibogae的幼虫会因猎物珊瑚（Porites compressa）释放的一种溶解诱导物而停止游动并下沉，当接触到无诱导物的水时又会重新游动。珊瑚礁上方水流中诱导物瞬间的精细空间分布呈丝状；因此，在水中游动或下沉的微小幼虫会以开/关的时间模式遇到高于阈值浓度的诱导物。模型结果表明，与使用随时间变化的精细诱导物分布计算相比，使用时间平均的诱导物浓度梯度来计算幼虫向珊瑚礁的输送速率会高估速率<15%（取决于触发幼虫下沉所需的诱导物阈值浓度）。对向基质输送速率有较大影响的幼虫行为方面包括游动速度和方向、下沉速度以及对诱导物的敏感性（阈值浓度）和反应性（引发反应的遭遇百分比）。相反，遇到诱导物后开始下沉或重新进入无诱导物的水后重新开始游动的滞后时间影响可忽略不计。
Larvae of many benthic marine animals set- tle and metamorphose in response to waterborne chem- ical cues. Can the behavioral responses of microscopic larvae in the water column to dissolved chemical cues affect their transport to the substratum in the turbulent, wave-driven flow characteristic of many shallow coastal habitats? We addressed this question using an individ- ual-based model of larvae of the sea slug Phestilla sibo- gae, transported in the oscillatory flow above coral reefs. Larvae of P. sibogae stop swimming and sink in response to a dissolved inducer released by their prey, the coral Porites compressa, and resume swimming when exposed to inducer-free water. The instantaneous fine-scale spa- tial distribution of inducer in the flow above a reef is fila- mentous; hence microscopic larvae swimming or sinking through the water encounter inducer above threshold concentration in on/off temporal patterns. Model results show that using a time-averaged inducer concentration gradient to calculate larval transport rates to the reef overestimates the rates by <15% (depending on the threshold concentration of inducer required to trigger larval sinking) compared with those calculated using time-varying, fine-scale inducer distributions. Aspects of larval behavior that have large effects on rates of trans- port to the substratum are swimming speed and direc- tion, sinking speed, and sensitivity (threshold concentra- tion) and responsivity (percent of encounters eliciting a response) to inducer. In contrast, lag times to start sinking after encountering inducer or to resume swimming after re-entering inducer-free water, have negligible effect.