Fig. 4

Muscular development in dwarf males of Dinophilus gyrociliatus. Phalloidin-labelled actin-filaments shown in green, labelling of DNA with DAPI shown in blue, animals are oriented with the anterior end up in dorso-ventral view (A-C), or to the left and in lateral view (D-I). a dorsal view of an one day old dwarf male with the anterior point of muscular origin formed; b dorsal region of the longitudinal and circular fibres forming in a two day old dwarf male in dorsal view; c ventral region of longitudinal and circular fibres in a two day old dwarf male, d musculature in a prehatching dwarf male; e-i section series with anterior to the left and posterior to the right through the copulatory organ in an adult dwarf male from the ventral (e) to the dorsal side (i), illustrating the penile cone (f, g) and the penile sheath (e-i). Abbreviations: alps – anterior loop of the outer sheath. cm – circular muscle, cmps – circular muscles of the penile sheath, dlm – dorsal longitudinal musculature, dlps – dorsal loop of the penile sheath, gpr – gonopore opening, lips – longitudinal inner muscles of the penile sheath, lops – longitudinal outer muscles of the penile sheath, pc – penile cone, pmr – posterior muscular ring, psm – penile sheath musculature, ros – ring around the gonopore formed by the outher sheath, test – testis, vllm – ventrolateral longitudinal muscle, vlps – ventral loop of the penile sheath, vpmo – ventroanterior point of muscular origin