Skip to main content
Log in

The unique gravireceptor organs of Pleurodasys helgolandicus (Gastrotricha: Macrodasyida)

  • Original Paper
  • Published:
Zoomorphology Aims and scope Submit manuscript

Abstract

The drumstick-like organs of the marine interstitial gastrotrich Pleurodasys helgolandicus Remane, 1927 were studied using optical and electron microscopy, in order to widen our knowledge of the sensory organs among gastrotrichs. The drumstick-like sensory organs are paired, symmetrical structures located on the dorsal side of the post-cephalic region of the body. Each sensory organ is formed by an outgrowth of the lamellar exocuticle covering the body surface, and it consists of an elongated, cylindrical hollow stalk surmounted by a hollow bulbous tip, housing in its cavity a dense spherical body. Compared with the three main sensory structures recognized among Gastrotricha, i.e., mechanoreceptors, photoreceptors, and chemoreceptors, the organization of the drumstick-like sensory organ matches that of mechanoreceptors. In particular, we suggest that the drumstick-like sensory organs of P. helgolandicus are gravireceptor organs, analogous to the orthopteran “plumb bob-like” receptors. This is the first description of a putative gravireceptor organ among gastrotrichs.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3

Similar content being viewed by others

References

  • Barber VC (1968) The structure of mollusc statocysts, with particular reference to cephalopods. Symp Zool Soc London 23:37–62

    Google Scholar 

  • Bischof HJ (1975) Die keulenförmigen sensillen auf den cerci der grille Gryllus bimaculatus als schwererezeptoren. J Comp Physiol 98:277–288

    Article  Google Scholar 

  • Boaden PJS (1963) Marine Gastrotricha from the interstitial fauna of some North Wales beaches. Proc Zool Soc London 140:485–502

    Google Scholar 

  • Ehlers U (1991) Comparative morphology of statocysts in the plathelminthes and the Xenoturbanellida. Hydrobiologia 227:263–271

    Article  Google Scholar 

  • Ermak TH, Eakin RM (1976) Fine structure of the cerebral pygidial ocelli in Chone ecaudata (Polychaeta: Sabellidae). J Ultrastruct Res 54:243–260

    Article  PubMed  CAS  Google Scholar 

  • Ferrero EA, Bedini C, Lanfranchi A (1985) An ultrastructural account of otoplanid Turbellaria neuroanatomy II. The statocyst design: evolutionary and functional implications. Acta Zool 66:75–87

    Google Scholar 

  • Gagné GD (1980) Ultrastructure of the sensory palps of Tetranchyroderma papii (Gastrotricha, Macrodasyida). Zoomorphologie 95:115–125

    Article  Google Scholar 

  • Gillespie PG, Walker RG (2001) Molecular basis of mechanosensory transduction. Nature 413:194–202

    Article  PubMed  CAS  Google Scholar 

  • Govindankutty AG, Nair NB (1969) The marine Gastrotricha from the interstitial fauna of the south-west coast of India. Bull Nat Inst Sci India 38:623–640

    Google Scholar 

  • Hartman HB, Walthall WW, Bennett LP, Stewart RR (1979) Giant interneurons mediating equilibrium reception in an insect. Science 205:503–505

    Article  PubMed  Google Scholar 

  • Hochberg R (2001) A special form of sensory cilia in Lepidodermella squamata (Gastrotricha: Chaetonotida). Ophelia 55:137–139

    Google Scholar 

  • Hochberg R, Litvaitis MK (2003) Ultrastructural and immunocytochemical observations of the nervous systems of three macrodasyidan gastrotrichs. Acta Zool 84:171–178

    Article  Google Scholar 

  • Hummon WD (1974) Some taxonomic revisions and nomenclatural notes concerning marine and brackish-water Gastrotricha. Trans Am Microsc Soc 92:194–205

    Article  Google Scholar 

  • Hummon WD (ed) (2007) Global database for marine Gastrotricha. http://132.235.243.28 at http://nas.biosci.ohio.edu or Google snap 818560

  • Keil T (1997) Functional morphology of insect mechanoreceptors. Microsc Res Techniq 39:506–531

    Article  CAS  Google Scholar 

  • Kristensen RM (1981) Sense organs of two marine Arthrotardigrades (Heterotardigrada, Tardigrada). Acta Zool 62:27–41

    Article  Google Scholar 

  • Kristensen RM (1991) Loricifera. In: Aschelminthes IV, Harrison FW, Ruppert EE (eds) Mycroscopic anatomy of invertebrates. Wiley-Liss, New York, pp 351–375

    Google Scholar 

  • Kristensen RM, Higgins R (1991) Kinorhyncha. In: Aschelminthes IV, Harrison FW, Ruppert EE (eds) Mycroscopic anatomy of invertebrates. Wiley-Liss, New York, pp 377–404

    Google Scholar 

  • Liesenjohann T, Neuhaus B, Schmidt-Rhaesa A (2006) Head sensory organs of Dactylopodola baltica (Macrodasyida, Gastrotricha): a combination of transmission electron microscopical and immunocytochemical techniques. J Morphol 267:897–908

    Article  PubMed  Google Scholar 

  • Neuhaus B (1997) Ultrastructure of the cephalic sensory organs of adult Pycnophyes dentatus and of the first juvenile stage of P. kielensis (Kinorhyncha, Homalorhagida). Zoomorphology 117:33–40

    Article  Google Scholar 

  • Pfannkuche O, Thiel H (1988) Sample processing. In: Higgins RP, Thiel H (eds) Introduction to the study of meiofauna. Smithsonian Institution Press, Washington, pp 134–145

    Google Scholar 

  • Remane A (1927) Neue Gastrotricha Macrodasyoidea. Zool Jahrb Abt Syst Oekol Geogr Tiere 54:203–242

    Google Scholar 

  • Rieger RM, Ruppert EE, Rieger GE, Schoepfer-Sterrer C (1974) On the fine structure of gastrotrichs with description of Chordodasys antennatus sp. n. Zool Scr 3:219–237

    Google Scholar 

  • Roth LM, Slifer EH (1973) Spheroid sense organs on the cerci of the polyphagid cockroaches (Blattaria: Polyphagidae). Int J Insect Morphol Embryol 2:13–24

    Article  Google Scholar 

  • Ruppert EE (1991) Gastrotricha. In: Aschelminthes IV, Harrison FW, Ruppert EE (eds) Microscopic anatomy of invertebrates. Wiley-Liss, New York, pp 41–109

    Google Scholar 

  • Storch V (1991) Priapulida. In: Aschelminthes IV, Harrison FW, Ruppert EE (eds) Microscopic anatomy of invertebrates. Wiley-Liss, New York, pp 333–350

    Google Scholar 

  • Teuchert G (1977) The ultrastructure of the marine gastrotich Turbanella cornuta Remane (Macrodasyoidea) and its functional and phylogenetical importance. Zoomorphologie 88:189–246

    Article  Google Scholar 

  • Todaro MA, Hummon WD, Balsamo M, Fregni E, Tongiorgi P (2001) Inventario dei Gastrotrichi marini italiani: una checklist annotata. Atti Soc Tosc Sci Nat Mem Series B 107:75–137

    Google Scholar 

  • Todaro MA, Leasi F, Tongiorgi P (2006) I Gastrotrichi del Mare di Alboran. 67° Congresso Nazionale dell’Unione Zoologica Italiana. Napoli, 12–15 settembre 2006

  • Vinnikov YA (1974) Sensory reception. Cytology, molecular mechanisms and evolution. Springer, Heidelberg

  • Walthall WW, Hartman HB (1981) Receptors and giant interneurons signaling gravity orientation information in the cockroach Arenivaga. J Comp Physiol 142:359–369

    Article  Google Scholar 

  • Wright KA (1991) Nematoda. In: Aschelminthes IV, Harrison FW, Ruppert EE (eds) Mycroscopic anatomy of invertebrates, vol 4. Wiley-Liss, New York, pp 111–195

    Google Scholar 

Download references

Acknowledgments

We are indebted to M. Curini-Galletti, F. Leasi and P. Tongiorgi for helping us during the collection of the Gastrotricha. M Curini-Galletti and E. Ferrero provided part of the literature on flat-worm statocysts. We are grateful to R.M. Kristensen for reading an early version of the manuscript. The Eclipse 90i Nikon microscope was funded by “Fondazione Cassa di Risparmio di Modena.” The research benefited also from a MIUR grant to M.A.T. (PRIN-2004—Diversità e zoogeografia dei Gastrotrichi del Mediterraneo). We are also grateful to Laura Valenti for accurate ink drawings, and to both anonymous reviewers for their constructive feedbacks and suggestions.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Roberto Marotta.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Marotta, R., Todaro, M.A. & Ferraguti, M. The unique gravireceptor organs of Pleurodasys helgolandicus (Gastrotricha: Macrodasyida). Zoomorphology 127, 111–119 (2008). https://doi.org/10.1007/s00435-008-0056-6

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00435-008-0056-6

Keywords

Navigation