Research on sperm is incorporated into many areas of ecology and evolution including including sexual selection, reproductive physiology and ecotoxicology, as well as comparative studies in evolution and phylogenetics. Currently, producing data on sperm morphology involves several time-consuming steps, particularly photographing sperm and measuring their length (e.g. head, midpiece, tail and total sperm length). Here, we present Sperm Sizer, a freely available Java program that semi-automates the process of measuring sperm length along the centre of the sperm (including head, midpiece, tail and total length). We compare sperm measurements made with Sperm Sizer to those made with the widely used non-automated software ImageJ, for sperm from a single bird species (the long-tailed finch Poephila acuticauda), eight species of passerine bird and eight species of lizard, and provide examples demonstrating that the program can measure at least some mammalian, fish and mollusc sperm. Sperm length measurements from Sperm Sizer are highly correlated to those made using ImageJ, demonstrating that Sperm Sizer produces high quality sperm length data while taking drastically less time. Our data suggests that Sperm Sizer measurements could possibly be incorporated into existing large datasets with a small correction, although this will need to be assessed on a case-by-case basis. We suggest that generally, sperm image quality (high contrast, minimal overlap of sperm, etc.) will be more important than the shape of the sperm for whether or not Sperm Sizer is for whether or not Sperm Sizer can be employed for a given project.

精子的研究被纳入生态和进化的许多领域，包括性选择，生殖生理学和生态毒理学，以及进化和系统发育的比较研究。当前，产生有关精子形态的数据涉及多个耗时的步骤，特别是拍摄精子并测量其长度（例如，头部，中段，尾部和总精子长度）。在这里，我们介绍了Sperm Sizer，这是一个免费的Java程序，它使沿着精子中心（包括头部，中段，尾部和总长度）的精子长度测量过程半自动化。我们将用Sperm Sizer进行的精子测量与使用广泛使用的非自动化软件ImageJ进行的测量进行比较，以测量单个鸟类（长尾雀科）的精子。Poephila acuticauda），八种雀形目鸟类和八种蜥蜴，并提供示例，说明该程序至少可以测量某些哺乳动物，鱼类和软体动物的精子。Sperm Sizer的精子长度测量结果与使用ImageJ进行的测量高度相关，这表明Sperm Sizer可产生高质量的精子长度数据，而所需时间却大大减少。我们的数据表明Sperm Sizer尽管可能需要根据具体情况进行评估，但可以将这些测量结果合并到现有的大型数据集中，而只需进行少量校正。我们认为一般，精子图像质量（高对比度，精子的最小重叠等）会比精子的形状更重要与否精子仪是与否精子仪可用于特定项目。