Fig. 6

Musculature of the posterior segments of Pycnophyes kielensis. Micrographs obtained with a confocal laser scanning microscope of two specimens, one female and one male. The musculature was stained with Alexa-488-labeled phalloidin and appears green. Cell nuclei where stained with DAPI and appear blue together with autofluorescence of the cuticle. a and f are maximum projections, b–e and g–j are single scans from of the maximum projections shown in a and f, respectively, from ventral to dorsal. Numbers indicate segment number, the animals are oriented with the anterior end upwards, and the scale bar is the same for all micrographs. a Female with overlay of a maximum projection of musculature over a transmission scan to show the relative position of the musculature within the cuticle and in relation to the lateral terminal spines. b Ventral scan of a with ventral longitudinal and lateral terminal spine muscles. c Ventral scan slightly more dorsal than b with prominent lateral terminal spine muscles. d Dorsal scan slightly more dorsal than c with dorsoventral muscles and gut opening muscle. e Dorsal scan with dorsal longitudinal muscles and the dorsal insertion point of dorsoventral muscles. f Male with overlay of maximum projection of musculature over transparent scan to show the relative position of the musculature to the cuticle, the penile spines, and the lateral terminal spines. g Ventral view with ventral longitudinal muscles and insertion point of dorsoventral muscles to the cuticle. h Ventral view slightly more dorsal than g with penile spine muscles. i Dorsal view slightly more dorsal than h with lateral terminal spine muscles. j Dorsal view with dorsal longitudinal muscles. dlm dorsal longitudinal muscle, dvm dorsoventral muscle, gm gut musculature, gom gut opening muscle, lts lateral terminal spine, ltsm lateral terminal spine muscle, psm penile spine muscle, vlm ventral longitudinal muscle