Non-ciliate sensory receptors of larvalMulticotyle purvisi (Trematoda, Aspidogastrea)

Abstract

Four types of presumptive non-ciliate sensory receptors of larvalMulticotyle purvisi (Trematoda, Aspidogastrea) are described by transmission electronmicroscopy. One pair of receptors in the mouth cavity has two to several electron-dense collars and a long crossstriated rootlet with some fibres fanning out from the basal body. Four pairs in the ventral wall of the posterior sucker and in the tegument ventral to the sucker contain numerous electron-dense collars and, diverging from the basal body, a large, round-ovoid ciliary rootlet that is cross-striated in its proximal and has numerous dense structures in its distal part. Two large bulbous receptors with much dense material in their apical parts and some desmosome-like structures occur in the lateral surface tegument at the level anterior to the posterior sucker, and similar smaller ones occur at the anterior end. A receptor with both a bulbous projection containing numerous vesicles with dense inclusions and some long cytoplasmic processes occurs at the posterior end.