Fig. 4 AZAN-stained paraffin histology. A in Hardly Venus's servant-morphological adaptations of Veneriserva to an endoparasitic lifestyle and its phylogenetic position within Dorvilleidae (Annelida)

Fig. 4 AZAN-stained paraffin histology. A Histological cross-section of a juvenile Aphrodita longipalpa featuring an endoparasitic immature Veneriserva pygoclava (denoted by a star). B Longitudinal section of V. pygoclava, highlighting the absence of a through gut, and continuous uninterrupted mesenteries. C–H Cross-sections through the anterior region of V. pygoclava, showing the muscularized pharynx with jaws culminating in blind termination at section G. Abbreviations—ac acicula, br brain, df dorsal felt, el elytra, ja jaws, mo mouth, ne nephridium, pha pharynx, vnc ventral nerve cord