Scope and Consequences of Variability in the Early Life History Traits of a Caribbean Coral Reef Fish

底栖海洋生物浮游幼虫阶段发生的事件可在调节开放种群方面发挥重要作用。浮游幼体阶段和底栖幼鱼阶段（定居和变态）之间的过渡一般被认为是许多底栖海洋鱼类（如珊瑚礁鱼类）生命中的关键时期，但这些阶段之间的联系相对较少受到关注。在幼虫阶段表现出的生物学性状不仅可以影响幼虫的存活，而且还可以影响随后的幼虫阶段的招募和存活。早期生活史（ELH）性状的自然变异模式、早期幼鱼死亡率和性状相关存活率是完全未知的。我们目前还不知道哪些幼虫能存活下来并成功定居，哪些又能在珊瑚礁上存活下来，包括能量消耗巨大的变态过程。虽然有关ELH特征的生态理论，赋予更高的生存已经发展为仔鱼在温带系统，很少有这种理论被扩展到整个过渡到少年，很少有数据可用于ELH性状和热带物种，如珊瑚礁鱼类的生存之间的关系。这项实地研究的目的是调查模式的ELH性状的自然变异的共同加勒比海珊瑚礁鱼类以及这种变化对从浮游生物到珊瑚礁过渡期间幼仔和幼鱼生存的影响。将在几个季节（6个月）内从佛罗里达群岛的地点对新招募的多个队列的双带海锦鱼进行普查和收集。和水文条件，以确定环境条件，ELH性状，和招聘成功之间的关系。新兵将被收集从复制网站与高和低密度的居民鱼，以研究如何变量的增长和死亡率进一步影响新兵ELH性状的分布。检查耳石记录的后期幼虫和年轻的少年将使识别内-队列，队列，并在ELH性状，如幼虫的生长速度，大小在年龄，大小和年龄在解决，和少年的生长速度，ESTA网站的差异。此外，集群特定的条件指数将测量后期幼虫和新出现的少年（1天的珊瑚礁）。耳石记录的纵向和横截面分析将揭示是否快速增长，较大或较老的幼虫，或幼虫的较高条件优先生存，以及是否大的招聘事件是由幼虫或新兵与特定的ELH性状。一个密集的一系列的青少年人口普查将提供每日特定年龄的死亡率，连同耳石衍生的ELH性状分析将定义之间的关系的增长，生存和选择性丧失ELH性状。因此，这项实地研究将是第一次广泛的原位调查ELH性状之间的关系和幼虫和年轻的少年礁鱼的生存。这项研究的结果将有助于我们了解珊瑚礁鱼类生活史中这个重要过渡阶段的动态以及导致这些开放种群招募变异性的因素。

Events occurring during the pelagic larval stage of benthic marine organisms can play an important role in the regulation of open populations. The transition between the pelagic larval stage and the benthic juvenile stage (settlement and metamorphosis) is generally recognized as a critical period in the life of many benthic marine fishes such as coral reef fishes, yet the linkage between these phases had received relatively little attention. Biological traits exhibited during the larval stage can influence not only larval survival, but also the recruitment and survival of subsequent juvenile stages. Patterns of natural variability in early life history (ELH) traits, early juvenile mortality, and trait--related survival are entirely unknown. We currently have no knowledge of which larvae survive to settle successfully, and which of those then survive the early life on the reef, including the energetically expensive process of metamorphosis. While ecological theory concerning the ELH traits that confer higher survival has been developed for larval fishes in temperate systems, rarely has this theory been extended across the transition to juveniles, and very few data are available on the relationship between ELH traits and survival for tropical species such as coral reef fishes.This field study is designed to investigate patterns of natural variability in the ELH traits of a common Caribbean coral reef fish and the consequences of this variation to the survival of young larvae and juveniles during the transition from the plankton to the reef. Multiple cohorts of newly recruited Thalassoma bifasciatum will be censused and collected from sites in the Florida Keys over several seasons (6 mos.) and hydrographic conditions to identify the relationship between environmental conditions, ELH traits, and recruitment success. Recruits will be collected from replicate sites with high and low densities of resident fishes to examine how variable growth and mortality further influence the distribution of ELH traits of recruits. Examination of the otolith record of late-stage larvae and young juveniles will enable the identification of within--cohort, among-cohort, and among-site differences in ELH traits such as larval growth rates, size-at-age, size and age at settlement, and juvenile growth rates. In addition, cohort-specific condition indices will be measured for late-stage larvae and emerging juveniles (1 d on the reef). Longitudinal and cross-sectional analyses of otolith records will reveal whether faster-growing, larger or older larvae, or larvae of higher condition preferentially survive, and whether large recruitment events are composed of larvae or recruits with particular ELH traits. An intensive series of juvenile censuses will provide daily age-specific mortality rates, which together with the otolith-derived ELH trait analyses will define the relationship between growth, survival, and selective loss of ELH traits. As such, this field study will be the first broad in situ investigation of the relationship between ELH traits and the survival of larvae and young juvenile reef fishes. Results of this study will contribute to our understanding of the dynamics of this important transitional phase in the life history of coral reef fishes and the factors contributing to recruitment variability in these open populations.