The surface topography of Benedenia sp. (Monogenea: Capsalidae)

Abstract

The tegumental surface of Benedenia sp. (Monogenea: Capsalidae), a skin-dwelling parasite of Haemulon sciurus (blue-striped grunt) from coastal waters of Bermuda, was examined using scanning electron microscopy. The dorsal surface of the body and haptor is covered with comparatively long, flexible microvilli (2 to 3 μm in length; density 5/μm2), and the ventral surface of the body is covered with short, stubby microvilli (0.5 μm in length; density 10/μm2). The surface of the two anterior adhesive discs has three transverse zones which differ morphologically: the anterior region has a reticulate texture with uniciliated structures arising from some of the elevated ridges; the middle zone has a dense mat of short microvilli with scattered uniciliated structures, each of which is surrounded by a collar of shorter protuberances; the posterior zone is smooth and lacks ciliated structures. The ventral surface of the haptor is also smooth with the bare extremities of the accessory sclerites and the anterior and posterior hamuli protruding. The surface topography of Benedenia sp. is compared with that of other monogeneans.