, Volume 123, Issue 3, pp 169–177 | Cite as

Musculature and nervous system of Gnathostomula peregrina (Gnathostomulida) shown by phalloidin labeling, immunohistochemistry, and cLSM, and their phylogenetic significance

  • Monika C. M. Müller
  • Wolfgang Sterrer
Original Article


Musculature and nervous system of Gnathostomula peregrina (Gnathostomulida, Scleroperalia) were reconstructed from whole animals by immunohistochemistry and confocal laser scanning microscopy. The F-actin muscular subset, stained with FITC-labeled phalloidin, consists of: (1) eleven pairs (four ventral, one ventrolateral, one dorsolateral, five dorsal) of longitudinal muscles; (2) two types of diagonal muscles (thin fibers throughout the body, and slightly thicker fibers of which seven pairs occur ventrally and two pairs dorsally); (3) evenly spaced thin circular fibers that gird the posterior half of the body, continuing less prominently into the anterior half; and (4) a complex pharyngeal and genital musculature. Dorsoventral muscles are absent. The organization of the FMRFamidergic nervous system shows: (1) a central nervous system with a frontal ganglion and one pair of longitudinal nerves ending in a terminal commissure, and one median ventral nerve; (2) eight to ten unipolar perikarya above, and up to ten bipolar perikarya in front of the brain; (3) a total of five (one unpaired, two paired) longitudinal nerves of the peripheral nervous system with two to four accompanying perikarya; and (4) a buccal ganglion of the stomatogastric nervous system with six to eight perikarya above the pharyngeal bulbus. Our results reveal the musculature and nervous system of Gnathostomula to be more complex than hitherto reported.


Phalloidin F-actin FMRFamide Nervous system Gnathostomulida cLSM 



We wish to thank Prof. Dr. Wilfried Westheide for taking the sediment samples in Bermuda and for valuable discussions about the manuscript. This is Contribution #51 from the Bermuda Biodiversity Project (BBP), Bermuda Aquarium Museum and Zoo.


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Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  1. 1.Spezielle Zoologie, Fachbereich 5Universität OsnabrückOsnabrückGermany
  2. 2.Bermuda Natural History MuseumBermuda

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