Contribution of the CASA system, based on open source software, to the assessment of sperm characteristics: informetric and usage-based approaches

ABSTRACT By using informetric tools, we evaluated the contribution and impact of the open source computer-assisted sperm analysis (CASA) software on sperm studies, especially pertaining to fish. The article was cited 125 times between 2007 and 2014 in four publication types (articles, doctoral dissertations, master’s theses, and books). Among articles, the number of citations increased at rate of three citations per year and the calculated h-index was 17. Of the studies that cited Wilson-Leedy and Ingermann (2007), fish were the main group of organisms studied (61 articles); of these, 34 articles used the open source CASA, covering 23 marine or freshwater species. Studies conducted in 12 countries were published in 21 journals. Four ways of knowledge sharing were identified: by direct partnership with the system developers; by knowledge multipliers, who worked directly with the system developers; by groups that adopted the system by their own initiative; and through expansion of cooperation networks with autodidacts. In regard to specific analytical procedures, motility, curvilinear velocity, average path velocity, and straight-line velocity were the main CASA parameters used to describe sperm movements. As expected, the usage of this tool has been increasing over the years, being a reliable and versatile alternative to more costly similar platforms. However, the potential of the CASA system has not been completely explored and it is our assessment that some results produced by CASA are poorly understood or even misunderstood.