Vesicles in the Proboscis of Acanthocephala

Abstract

An isolated fluid-filled vesicle in the proboscis of Corynosoma hamanni is redescribed as the anterior end of the dorsal wall of the inner muscle layer of the proboscis receptacle. Various authors (Yamaguti, 1935; Montreuil, 1958; Nickol and Holloway, 1968) have described saccular vesicles in the proboscis of several species of Acanthocephala. Yamaguti (1935) described, in Longicollum pagrosomi, a large oval-to-elliptical mass of unknown nature that is enclosed in a thin capsule and attached to the inner surface of the proboscis i l l id-fil ed vesicle in the proa a i is redescribed as the sal all of the inner uscle layer tacle. ( a ti, 1935; ontreuil, apex. It appears from this description that he was observing the 2 apical nuclei (sense organ) found in many, if not all, species of Palaeacanthocephala. In the proboscis of Polymorphus capellae he described 2 elongated saccular vesicles of different sizes arising from the inner surface of the posterior end of the proboscis that are usually directed anterior and push aside the invertor muscles of the proboscis as they extend anterior. These proboscis vesicles, as he called them, are enclosed by a very thin membrane and contain a finely granulated or homogeneous substance of unknown nature. ex. It a pears from thi description that he was serving the 2 apical nucl i (sense orga ) found any, if not all, species of Palaeacanthocepha. In the pr bo cis of Polymorphus cap llae he scribed 2 elongated saccular vesicles of differThis content downloaded from 207.46.13.149 on Mon, 03 Oct 2016 06:14:31 UTC All use subject to http://about.jstor.org/terms 586 THE JOURNAL OF PARASITOLOGY, VOL. 76, NO. 4, AUGUST 1990 Unfortunately, Yamaguti (1935) did not illustrate these vesicles and his descriptions do not contain sufficient detail to permit evaluation. Montreuil (1958) described, in Corynosoma magdaleni, a large mass of tissue situated dorsally on the inner surface of the proboscis and proboscis receptacle. The tissue has a homogeneous, slightly granular appearance, the portion within the proboscis being distinctly separated from other tissues. In the proboscis receptacle, it is in close contact with the inner surface of the inner wall. He described this mass of tissue as flattened dorsoventrally, evenly rounded anteriorly, and extending anterior to the largest hooks, giving it a shieldlike appearance when viewed from a dorsal aspect. He described, at the level of the neck, a ganglion cell on the mid-line of the dorsal surface of this tissue. Harada (1931) described the anterior end of the dorsal and ventral walls of the proboscis receptacle of Bolbosoma turbinella as Markbeutels or cytoplasmic-filled sacs. The dorsal wall extends more anterior into the proboscis than into the ventral wall, which terminates at the junction of the neck and the base of the probos-