Genital morphology and its changes from young and elder specimens of Agabus uliginosus sensu lato A, B morphology and aedeagus of an elder specimen in right side lateral (A) and dorsal (B) views, with measured parameters a-d. C–G Dorsal views of aedeagi from different age classes of A. uliginosus s. l. C corresponds to A. lotti, while D–G to A. uliginosus s. str. with increasing age C–E Hungarian population F, G old male specimen from Rudna, Mühlgast, Poland F, G show the same aedeagus isolated from a specimen preserved in ethanol, then dried for 5 min (F), and for 15 min or more (G). Black arrows on G symbolize movements of phallobases H–L side view of aedeagi and morphology of internal genital organs of an immature (H, K, #H04), an elder (I, #H27) and an old (J, L, #H30) specimen of A. uliginosus s. l. from the Hungarian population. H and K correspond to A. lotti, J and L to A. uliginosus s. str, while I shows a young specimen of A. uliginosus s. str. as a transition between them. Abbreviations: de: ductus ejaculatorius (checkered in H–J), ec: ectadenies (dotted in H–J), sd: spermatic duct (cross-striped in H–J), p: phallobase, t: testes (dotted in H–J), w.p: width of phallobase, w.de: width of ductus ejaculatorius. The triangles and the interrupted horizontal line in H–J illustrate the origin of the phallobase as indicated by b in A. In K (#H04) and L (#H30) anterior margin and origin of ductus ejaculatorius is marked by arrows. Scale bars: 1 mm (different scales refer to A–G and H–J). For K and L, 20-fold magnification was used.