Flume Studies of the Effects of Reproductive Mode, Larval Concentration and Hydrodynamics on Larval Settlement Rate of Infaunal Invertebrates

繁殖方式、幼虫浓度和水动力对动物内无脊椎动物幼虫沉降率影响的水槽研究

• 批准号: 9729972
• 负责人: Victoria Starczak
• 金额: $ 31.96万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-04-01 至 2001-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9729972&HistoricalAwards=false
• 关键词: Flume; Studies; Effects; Reproductive; Mode

The objective of this laboratory flume study is to quantify settlement rate as a function of larval availability for species of benthic invertebrates that vary in reproductive mode (i.e., with planktotrophic or lecithotrophic larvae) and taxonomic affinity (polychaetes and bivalves). Larval availability, here defined as the supply of larvae to the bed, is a product of a larval concentration and a velocity term. Thus, experiments are designed specifically to test the relative influence of these two factors on settlement rate. Three hypotheses will be tested. Hl: Settlement rate varies as a function of reproductive mode; lower settlement rates and higher settlement variability are associated with planktotrophic as compared with lecithotrophic larvae. H2: Settlement rate increases with increasing planktonic larval concentration until it reaches an asymptotic value, at which point the bed is saturated. H3: Larval flux to the bed can be described as an eddy diffusion process, where the key hydrodynamic parameter is the boundary shear velocity. In the course of testing these hypotheses, this study will also determine (1) the relationship between bulk concentration of larvae in the flow and flux of larvae to the bed, (2) if larval settlement is directly proportional to larval availability, and (3) the probability of settlement (i.e., of a larva remaining on the bed once deposited). A long term goal of this research is the prediction of settlement rate in the field from data on larval availability and flow, and thus experiments will be conducted so that a general, quantitative expression can be developed to predict settlement from larval flux to the bed.

这项实验室水槽研究的目的是量化沉降率作为繁殖模式不同的底栖无脊椎动物物种的幼虫可用性的函数（即，与浮游营养型或卵营养型幼虫）和分类学上的亲缘关系（多毛类和双壳类）。幼虫可用性，这里定义为幼虫的床，是一个产品的幼虫浓度和速度项。因此，设计了专门的实验来测试这两个因素对沉降速率的相对影响。将检验三个假设。Hl：定居率作为生殖模式的函数而变化;与lecithotrophic幼虫相比，低定居率和高定居变异性与lecithotrophic相关。H2：沉降率随着浮游幼虫浓度的增加而增加，直到它达到一个渐近值，在该点处，床是饱和的。H3：幼虫到床的通量可以被描述为一个涡动扩散过程，其中关键的水动力参数是边界剪切速度。在测试这些假设的过程中，本研究还将确定（1）水流中幼虫的总浓度与幼虫到床的通量之间的关系，（2）幼虫沉降是否与幼虫可用性成正比，以及（3）沉降的概率（即，一个幼虫留在床上一旦沉积）。本研究的一个长期目标是从幼虫可用性和流量的数据预测在现场的沉降率，因此将进行实验，以便可以开发一个通用的，定量的表达式来预测从幼虫流量到床的沉降。