Probable non-receptor tyrosine-protein kinase which plays a role in spermatid activation (spermiogenesis) in hermaphrodites. ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Localizes mainly in the cytoplasm of stage I spermatocytes and at the cell membrane of stage II spermatocytes and spermatids. Expression is restricted to male germline. Belongs to the protein kinase superfamily. Tyr protein kinase family. Fes/fps subfamily.