Premium
Morphology of chemosensory organs required for feeding in the leech hirudo medicinalis
Author(s) -
Elliott Ellen J.
Publication year - 1987
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.1051920208
Subject(s) - hirudo medicinalis , leech , biology , anatomy , cilium , ultrastructure , mechanoreceptor , chemoreceptor , electron microscope , morphology (biology) , zoology , microbiology and biotechnology , sensory system , neuroscience , optics , biochemistry , physics , receptor , world wide web , computer science
Sensilla that line the upper edge of the lip in the leech Hirudo medicinalis and that contain chemoreceptors required for feeding were examined in the scanning and transmission electron microscopes. The sensilla include two size‐classes of ciliated button‐like mounds—one about 35 μm in diameter and another about 10 μm in diameter. The larger sensilla are at the center of unpigmented patches of skin which are visible in the light microscope, while the smaller sensilla have not been previously described as distinct structures. Electron microscopy, though not light microscopy, shows that the lip sensilla differ markedly from the segmental sensilla of the leech, which have been shown to mediate mechanoreception and photoreception. In particular, the chemosensory lip sensilla contain multiciliated cells with cilia of a uniform length, whereas the segmental sensilla contain uniciliated cells with long, whip‐like cilia, as well as multiciliated cells with short, stiff cilia. Thus, the two types of sensilla differ morphologically as well as functionally. In addition to the ciliated sensilla along the upper lip, structures consisting of a short, club‐like process surrounded by granular material were observed inside the mouth. These structures may also be chemosensory organs.