spirocyst

spirocyst

[′spī·rə‚sist]
(invertebrate zoology)
A thin-walled capsule that contains a long, unarmed, eversible, spirally coiled thread of uniform diameter; found in cnidarians.
References in periodicals archive ?
Interspecific mucus enhanced nematocyst discharge by 44% and spirocyst discharge by 90%, as compared to baseline discharge obtained in seawater alone.
Specimens of Haliplanella were transferred from the mass culture to 35-mm diameter plastic petri dishes filled with natural seawater and were tested for spirocyst discharge by using a modification of methods previously described (Krayesky et al., 2010).
Regulation of spirocyst discharge in the model sea anemone, Nematostella vectensis.
Chemo- and mechanore-ceptors located on the supporting cells (Watson and Hessinger, 1988) control nematocyst and spirocyst discharge from the cnidocytes (Thorington and Hessinger, 1990).
Anemone tentacles contain two types of cnidae: the adhesive spirocysts and the venomous nematocysts (Thorington and Hessinger, 1996).
It is also possible that wall structure may differ with nematocyst type, just as the wall of a spirocyst differs from that of a nematocyst (e.g., Mariscal et al., 1976).
Finally, I found differences in spirocyst size among tissues and species to be consistent with apparent differences in the selective regimes; however, increase in spirocyst size with body size was similar for all populations, with scaling exponents similar to those reported for cell size variation within and among animal species (Munro, 1969; Munro and Gray, 1969; Maldonado et al., 1974; Peters, 1983; Calder, 1984; Stevenson et al., 1995).
To compute scaling exponents, anemone wet weights and mean dimensions of the spirocyst capsules were transformed to common logarithms (base 10) for analysis.
The combined dose-responses of Type B and Type C CSCCs to NANA for nematocyst discharge, spirocyst discharge, and adhesive force are characteristically biphasic ([ILLUSTRATION FOR FIGURES 2a-c OMITTED], open circles; Thorington and Hessinger, 1990).
The calculated Type B dose-responses of both mastigophore and spirocyst discharge are narrow and biphasic.
On the basis of the adhesive property of everted spirocyst tubules and the penetrating and venomous properties of mastigophores (Mariscal, 1974), it has been commonly inferred that penetrant nematocysts principally envenomate and immobilize prey, while spirocysts principally attach stung prey and inert substrates to the tentacles (McFarlane and Shelton, 1975; also, "Spirocysts are adhesive organelles which function both in prey capture and substrate attachment," Mariscal et al., 1977).
Because we have no way of nulling the contribution of discharging spirocysts or of specifically blocking only spirocyst discharge, the contribution of discharging mastigophores cannot be directly measured as it was for spirocysts.