Structure of nematocysts from Polypodium hydriforme was studied by scanning and transmission electron microscopy. Two nematocyst types were observed: holotrichous isorhizas with minute spines, and true atrichous isorhizas. Among holotrichous isorhizas four morphological categories were distinguished based on differences in morphology of their discharged stinging tubules. The cnidom of P. hydriforme possesses no specialized penetrant types. Instead, Polypodium uses holotrichous isorhizas as penetrants during prey capture. Stinging tubules of holotrichous isorhizas display two helical rows of tiny spines in the discharged state and possess two helical folds in the undischarged state, thus corresponding to double-helical symmetry. Double-helical symmetry has never been described for nematocysts of any cnidarians, thus being a peculiar feature of P. hydriforme.
Key words: Polypodium hydriforme, nematocyst, atrichous isorhiza, holotrichous isorhiza, penetrants, symmetry
Keywords
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2004 Kluwer Academic Publishers
About this paper
Cite this paper
Ibragimov, A., Raikova, E. (2004). Nematocysts of Polypodium hydriforme, a cnidarian parasite of acipenseriform fishes. In: Fautin, D.G., Westfall, J.A., Cartwrigh, P., Daly, M., Wyttenbach, C.R. (eds) Coelenterate Biology 2003. Developments in Hydrobiology, vol 178. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-2762-8_20
Download citation
DOI: https://doi.org/10.1007/978-1-4020-2762-8_20
Publisher Name: Springer, Dordrecht
Print ISBN: 978-1-4020-2761-1
Online ISBN: 978-1-4020-2762-8
eBook Packages: Springer Book Archive