PRF: Host Race Speciation in Sponge-dwelling Shrimps

物种的起源是生物学中的一个基本问题。地理隔离与生态专门化在促进物种形成方面的重要性是一个持久的争议。海绵虾（Synalpheus）种类繁多（100种），在世界各地的珊瑚礁上数量丰富；有几个特征使它们成为测试生态位转移是否能在同域种群中启动物种形成的理想候选者。这些特点包括高宿主特异性、低移动性和与宿主交配。近年来的研究表明，联耳藻在种群分布和同工酶频率上存在显著的宿主相关分化，以及未描述的宿主特异性隐种的高频率。本研究将发展1)对广泛寄主-通用型S. brooksi的同域与地理距离较远的茧的遗传（异化酶）和寄主利用差异进行批判性分析；2)分析几种目前未被识别的隐种联翅虫的遗传、行为和形态特征及其宿主关联；3)构建加勒比海螺的系统发育树，包括新定义的物种，宿主使用数据和生活史特征可以映射到该树上，以严格测试该群体的海绵生活习惯与辐射之间的联系。

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.