- Data from: A test for within-lake niche differentiation in the nine-spined sticklebacks (Pungitius pungitius)(2017-05-09) Calboli, Federico C. F.; Byström, Pär; Merilä, Juha; University of Helsinki - Calboli, Federico C. F.; Umeå University - Byström, Pär; University of Helsinki - Merilä, Juha