Light microscopy of third stage larvae (L3) morphologically compatible with <i>Angiostrongylus cantonensis</i>, obtained from <i>Theba pisana</i>.

<p>General view of third-stage larvae with one sheath (<i>S</i>). A characteristic “T”-shaped structure (<i>TS</i>) is apparent at the anterior end of the sheath that surrounds the L3 larva (a). Posterior end of L3 larva with anus (<i>A</i>) at subterminal position. Anus cuticle (<i>AC</i>) is completely molted and can be seen on the sheath (b). Anterior end of L3 larva with esophagus bulbus (<i>EB</i>), excretory pore (<i>EP</i>) and nervous ring (<i>NR</i>) (c).