Morphological data from: Strong species structure but weak geographical structure in demersal Lake Victoria cichlids

Studying phenotypic and genetic differentiation between very young species can be very informative with regard to learning about processes of speciation. Identifying and characterizing genetic species structure and distinguishing it from spatial genetic structure within a species is a prerequisite for this and is often not given sufficient attention. Young radiations of cichlid fish are classical speciation study systems. However, it is only during the past decade that population genomics based on next-generation sequencing has begun to provide the power to resolve species and distinguish speciation from spatial population structure for the youngest of these radiations. The Lake Victoria haplochromine cichlids constitute the youngest large cichlid fish radiation, probably less than 20,000 years old. Earlier work showed that communities of rocky reef cichlids are composed of many reciprocally monophyletic species despite their very recent origins. Here, we build on this work by studying ..., Fish were collected on a research transect in the Mwanza Gulf of Lake Victoria. We measured 15 morphological traits that have proven powerful for quantifying intraspecific and interspecific morphological variation in haplochromine cichlids of Lake Victoria: standard length (SL), head length (HL), head width (HW), body depth (BD), lower jaw length (LJL), lower jaw width (LJW), snout length (SnL), snout width (SnW), cheek depth (ChD), preorbital depth (POD), preorbital width (POW), interorbital width (IOW), eye length (EyL) and depth (EyD), and premaxillary pedicel length (PPL). We measured 661 individuals using digital calipers., Excel

研究极年轻物种间的表型与遗传分化，对于理解物种形成（speciation）过程具有重要的学术价值。鉴定并表征物种的遗传结构，并将其与物种内的空间遗传结构相区分，是此类研究的前提条件，但这一点往往未得到足够重视。慈鲷鱼类的年轻演化辐射类群是经典的物种形成研究体系。然而，直至过去十年间，基于下一代测序（next-generation sequencing）的群体基因组学，才具备足够效力来解析这些最年轻演化辐射类群中的物种，并厘清物种形成与空间群体结构之间的差异。维多利亚湖单倍型慈鲷（haplochromine cichlids）是目前已知最年轻的大型慈鲷演化辐射类群，其起源时间可能不足2万年。此前的研究表明，尽管起源时间极近，岩礁慈鲷群落仍由多个互为单系的物种所构成。本研究基于此前的工作展开……研究样本采集自维多利亚湖姆万扎湾的研究样带。本研究测量了15个经证实可有效量化维多利亚湖单倍型慈鲷种内与种间形态变异的形态性状：标准体长（standard length, SL）、头长（head length, HL）、头宽（head width, HW）、体高（body depth, BD）、下颌长（lower jaw length, LJL）、下颌宽（lower jaw width, LJW）、吻长（snout length, SnL）、吻宽（snout width, SnW）、颊部深度（cheek depth, ChD）、眶前深度（preorbital depth, POD）、眶前宽度（preorbital width, POW）、眶间距（interorbital width, IOW）、眼长（eye length, EyL）与眼径（eye depth, EyD），以及前上颌柄长（premaxillary pedicel length, PPL）。研究团队使用数显游标卡尺对661个个体完成了形态测量。本数据集以Excel格式存储。