Summary
The ultrastructure of the pusule apparatus has been investigated in some 40 dinoflagellates from both feshwater and marine environments. The morphology of the organelle is varied and seven more or less distinct types have been identified. These can be grouped into two categories:
-
a)
Pusules with pusule vesicles: vesicles opening directly into the flagellar canal; vesicles opening into a collecting chamber which branches from the flagellar canal; pusule with internal collecting chamber surrounded by vesicles; complex tubular pusule with vesicles.
-
b)
Pusules constructed of tubules or sack only: simple tubular pusule which may have a collecting chamber; tubular pusule with invaginations of the walls; sack pusule with invaginated walls.
A characteristic feature of the structure of the vesicles, when present, and of the tubules and sacks is the two-membrane nature of the 14–20 nm thick wall. This is constructed of plasma-membrane, invaginated from the flagellar canal, to which is appressed a vacuolar membrane. The vesicles and tubules are always surrounded by extensions of the cell vacuolar system. Various hypotheses concerning the function of the pusule are discussed and it is concluded that it is most likely an excretory or osmo-regulatory organelle.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bibby, B. T., andJ. D. Dodge, 1972: The encystment of a freshwater dinoflagellate: A light and electron microscopical study. Br. phycol. J.7, 85–100.
Biecheler, B., 1952: Recherches sur les Péridiniens. Bull. biol. Fr. Belg. (Suppl.)36, 1–149.
Bütschli, O., 1885: Dinoflagellata. Bronn's Klass. u. Ordn. des Thierreichs1, 906–1029.
Cachon, J., M. Cachon, etC. Greuet, 1970: Le système pusulaire de quelques Péridiniens libres ou parasites. Protistologica6, 467–476.
Crawford, R. M., and J. D.Dodge: The dinoflagellate genusWoloszynskia II. The fine structure ofW. coronata. Nova Hedwigia. (In press.)
— — andC. M. Happey, 1971: The dinoflagellate genusWoloszynskia. I. Fine structure and ecology ofW. tenuissima from Abbot's Pool, Somerset. Nova Hedwigia19, 825–840.
Dodge, J. D., 1967: Fine structure of the dinoflagellateAureodinium pigmentosum gen. et sp. nov. Br. phycol. Bull.3, 327–336.
— andR. M. Crawford, 1968: Fine structure of the dinoflagellateAmphidinium carterae Hulburt. Protistologica4, 231–242.
— —, 1969: The fine structure ofGymnodinium fuscum (Dinophyceae). New Phytol.68, 613–618.
— —, 1970 a: A survey of thecal fine structure in theDinophyceae, Bot. J. Linn. Soc.63, 53–67.
— —, 1970 b: Morphology and fine structure of the dinoflagellateCeratium hirundinella. J. Phycol.6, 137–149.
— —, 1971: Fine structure of the dinoflagellateOxyrrhis marina. I. The general structure of the cell. Protistologica.7, 295–304.
Fritsch, F. E., 1935: The structure and reproduction of the algae. Vol. 1. Cambridge: University Press.
Haye, A., 1930: Über den Exkretionsapparat bei den Protisten, nebst Bemerkungen über einige andere feinere Strukturverhältnisse der untersuchten Arten. Arch. Protistenk.70, 1–86.
Kevin, M. J., W. T. Hall, J. J. A. McLaughlin, andP. A. Zahl, 1969:Symbiodinium microadriaticum Freudenthal, a revised taxonomic description, ultrastructure. J. Phycol.5, 341–350.
Kofoid, C. A., 1909: OnPeridinium steini Jorgensen, with a note on the nomenclature of the skeleton of thePeridinidae. Arch. Protistenk.16, 25–47.
- and O.Swezy, 1921: The free-living unarmored dinoflagellata. Mem. Univ. California. Vol.5.
Kubai, D. S., andH. Ris, 1969: Division in the dinoflagellateGyrodinium cohnii (Schiller). J. Cell Biol.40, 508–528.
Leadbeater, B., andJ. D. Dodge, 1966: The fine structure ofWoloszynskia micra sp. nov., a new marine dinoflagellate. Br. phycol. Bull.3, 1–17.
Manton, I., andG. F. Leedale, 1961: Observations on the fine structure ofParaphysomonas vestita, with special reference to the Golgi apparatus and the origin of scales. Phycologia1, 37–50.
Mercer, E. H., 1959: An electron microscopic study ofAmoeba proteus. Proc. Roy. Soc. B.150, 216–232.
Mignot, J. P., 1970: Remarques sur le developpement du reticulum endoplasmique et du système vacuolaire chez les gymnodiniens. Protistologica6, 267–281.
Norris, R. E., 1966: Unarmoured marine dinoflagellates. Endeavour35, 124–128.
Schmitter, R. E., 1971: The fine structure ofGonyaulax polyedra, a bioluminescent marine dinoflagellate. J. Cell Sci.9, 147–173.
Schneider, L., 1960: Elektronenmikroskopische Untersuchungen über das Nephridialsystem vonParamaecium. J. Protozool.7, 75–90.
Schütt, F., 1895: Die Peridineen der Plankton-Expedition. Ergebn. Plankton-Exped. Humboldt-Stiftung,4, 1 (Keil & Leipzig).
Taylor, D. L., 1968:In situ studies on the cytochemistry and ultrastructure of a symbiotic marine dinoflagellate. J. mar. biol. Ass. U.K.48, 349–366.
—, 1971 a: Ultrastructure of the zooxanthellaEndodinium chattonii in situ. J. mar. biol. Ass. U.K.51, 227–234.
—, 1971 b: On the symbiosis betweenAmphidinium klebsii andAmphiscolops langerhansi. J. mar. biol. Ass. U.K.51, 301–313.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Dodge, J.D. The ultrastructure of the dinoflagellate pusule: A unique osmo-regulatory organelle. Protoplasma 75, 285–302 (1972). https://doi.org/10.1007/BF01279820
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01279820