PRF: Host Race Speciation in Sponge-dwelling Shrimps

物种起源是生物学中的一个基本问题。一个持久的争论涉及到地理隔离和生态专业化在促进物种形成方面的相关重要性。海绵栖息的对虾(Synalpheus)高度多样化(100种)，在世界各地的珊瑚礁上数量丰富；几个特征使它们成为测试生态位变化是否可以在共域种群中启动物种形成的理想对象。这些问题包括高寄主专一性、低迁移率和与寄主相关的交配。最近的研究揭示了联结线虫在人口学和等位酶频率上与寄主相关的显著分化，以及未描述的寄主特定隐蔽物种的高频率。这项研究将1)对广泛存在的寄主通才S.brooksi的同域和地理上相距遥远的Deme之间的遗传(异源)和寄主利用差异进行关键分析；2)分析几个目前未被识别的Synalpheus神秘物种及其寄主关联的遗传、行为和形态特征；3)构建加勒比海海绵的系统发育树，包括新定义的种，将寄主使用数据和生活史特征映射到该树上，以严格检验海绵栖息习性与该类群辐射之间的关联。

The origin of species is a fundamental problem in biology. An enduring controversy concerns the relevant importance of geographic isolation versus ecological specialization in promoting speciation. Sponge-dwelling shrimps (Synalpheus) are highly diverse (100 species) and abundant on coral reefs worldwide; several characteristics make them ideal candidates for testing whether niche shifts can initiate speciation in sympatric populations. These include high host specificity, low mobility, and mating in association with the host. Recent studies have revealed significant host-associated differentiation in demography and allozyme frequencies within Synalpheus species, as well as high frequency of undescribed host-specific cryptic species. This research will develop 1) a critical analysis of genetic (allomyze) and host use differentiation among sympatric versus geographically distant demes of the widespread host- generalist S. brooksi; 2) analyze genetic, behavioral, and morphometric characteristics of several currently unrecognized cryptic species of Synalpheus and their host associations; 3) construct a phylogenetic tree for Caribbean Synalpheus, including newly defined species, onto which host use data and life history characters can be mapped to test rigorously for association between the sponge-dwelling habit and the radiation of this group.