Zoomorphology

, Volume 101, Issue 1, pp 1–15

Ultrastructure of multiciliated collar cells in the pilidium larva of Lineus bilineatus (Nemertini)

Authors

  • Carl-Erik Cantell
    • Institute of ZoologyUppsala University
  • Åke Franzén
    • Section of Invertebrate ZoologySwedish Museum of Natural History
  • Terry Sensenbaugh
    • Institute of ZoologyUppsala University
Article

DOI: 10.1007/BF00312027

Cite this article as:
Cantell, C., Franzén, Å. & Sensenbaugh, T. Zoomorphology (1982) 101: 1. doi:10.1007/BF00312027

Summary

The ultrastructure of the apical plate of the free-swimming pilidium larva of Lineus bilineatus (Renier 1804) is described with particular reference to the multiciliated collar cells. In the multiciliary collar cells there are several, up to 12, cilia surrounded by a collar of about 20 microvilli extending from the cells' apical surface. The cilia have the typical 9+2 axoneme arrangement and are equipped with striated caudal rootlets extending from the basal bodies. No accessary centriole or rostral rootlet were observed. Microvilli surrounding the cilia are joined in a cylindrical manner by a mucus-like substance to form a collar. In comparison with many sensory receptor cells built on a collar cell plan the multiciliary collar cells of the pilidium larva apical plate are rather simple and unspecialized. In other pilidium larvae monociliated collar cells are found in the apical plate. The possible function and phylogenetic implications of multiciliated collar cells in Nemertini are briefly discussed.

List of Abbreviations

a

axoneme

b

basal body

c

cilia or flagella

d

desmosome

G

Golgi apparatus

m

mitochondria

mf

microfilaments

mu

mucus

mv

microvilli

n

nucleus

nt

neurotubules

pm

plasma membrane

r

rootlet

ri

ribosomes

v

secretory vesicles

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Copyright information

© Springer-Verlag 1982