Fig. 3 in Polyclinum constellatum (Tunicata, Ascidiacea), an emerging non-indigenous species of the Mediterranean Sea: integrated taxonomy and the importance of reliable DNA barcode data Abstract

Fig. 3: A) Whole zooid of Polyclinum constellatum, showing a clear division into thorax, abdomen and post-abdomen with a long vascular stolon. ab, abdomen; pa, post-abdomen; th, thorax; vs, vascular stolon; B) Zooid with evident pharynx, rectum, anus and four embryos incubated in the atrial cavity. The funnel-shaped oesophagus, the smooth stomach and the twisted gut loop are visible in the abdomen. The post-abdomen shows the heart at its terminal end, as well as several rounded testicular follicles and the ovary, with the gonoducts running parallel to the rectum. an, anus; e, embryos; gd, gonoducts; gl, gut loop; oe, oesophagus; ov, ovary; h, heart; r, rectum; st, stomach; tf, testicular follicles; C) Magnification of the oral siphon with six pointed lobes (arrows) and six longitudinal muscle bands (indicated with numbers 1-6); D) Branchial sac with 18 rows of stigmata and narrow languets of the dorsal lamina (arrows); E) Magnification of the pharynx, with minute papillae (arrows) at the level of the transverse vessels; F) Magnification of the six-lobed anus (lobes indicated with numbers 1-6).