Light micrographs of developmental stages of Babesia sp. (EU1) from the midgut of I. ricinus females after an infectious blood meal with in vitro cultured parasites (May-Grünwald Giemsa based stain). Line 1: individual elongated Strahlenkörper with only one nucleus and some protrusions. Line 2: examples of two Strahlenkörper cojoined with close adherence. Line 3: bi-nucleated parasites, possibly representing zygotes from the fusion of two Strahlenkörper.