Surface Sensilla on the Predaceous Fresh-Water Leech Erpobdella montezuma: Possible Importance in Feeding

• Published in: Transactions of the American Microscopical Society 1986-01, Vol.105 (1), p.21-30
• Main Authors: Blinn, Dean W., Wagner, Vincent T., Grim, J. Norman
• Format: Article
• Language: English
• Subjects: Amplitude; Annelida and closely related phyla: sipuncula. Echiura. Nemertinea; Biological and medical sciences; Cilia; Earthworms; Fundamental and applied biological sciences. Psychology; Invertebrates; Microtubules; Microvilli; Sensilla; Specimens; Swimming; Tactition; Transmission electron microscopy
• ISSN: 0003-0023
• DOI: 10.2307/3226546

Sensilla of the predaceous fresh-water leech Erpobdella montezuma were examined by scanning and transmission electron microscopy. Densities of sensilla and cilia within each sensillum were highest in the anterior-most annulus and were less in more posterior annuli. The most dramatic decrease was between annulus 1 and 3; there was little difference in densities of each from midbody to the posterior region. The highest densities of sensilla were found on the posterior sucker ($\bar x = 48.0 \times 10^{3}/cm^2$) and annullus 1 ($\bar x = 36.1 \times 10^{3}/cm^2$). In our preparations, cilia near the mouth and on the sucker were flush with the epidermal surface, but those in other regions protruded. Arrangement of G (grouped) and S (single) cilia along the longitudinal axis of the leech are described; the G cilia typically comprise 70-90% of the total, except on the dorsal posterior end where G cilia are ca. 46% of the total. The ultrastructure of G and S cilia was examined. Feeding experiments comparing response to prey species that swim in the water column with response to a more benthic congeneric prey species suggests that movement by prey is important in their detection by this leech. We postulate that the sensilla are important in detecting these movements.