Fig. 3

Paraspermatozoa of Adelomelon ancilla. a Light microscope image. Modified Masson’s trichrome. General view of the paraspermatozoa showing a vermiform aspect. Note the acidophilic area in the apex. b Transverse sections (TS) through apex showing electron-dense material enclosing axonemes. c TS posterior section showing peripheral axonemes. d LS main body region of paraspermatozoa with dense vesicles present. e TS of paraspermatozoa showing 52 axonemes. Note the spiral disposition of the axonemes. f TS main body region contains dense vesicles and a large mitochondrion, showing 18 peripheral axonemes. g TS main body region contains dense vesicles, mitochondrion, and axonemes in internally and peripherally. h Seminal vesicle, paraspermatozoa join to euspermatozoa ax axoneme, m mitochondrion, pz paraspermatozoa, dv dense vesicles