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 ?
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).
2001); (6) have tentacle cnidomes consisting of spirocysts, microbasic p-mastigophores, and basitrichous isorhizas in the same ratio (Hand, 1955; Giebel et al, 1988); and (7) reside in the same Subtribe (Acontiaria; Stepenson, 1935).
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.
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.
Data on spirocyst sizes were collected systematically by scanning each slide (as described in Williams, 1996) and measuring maximum lengths and widths (method of Hand, 1954) of the first 20 clearly visible, intact, and unfired capsules with their long axes parallel to the plane of the slide.
To compute scaling exponents, anemone wet weights and mean dimensions of the spirocyst capsules were transformed to common logarithms (base 10) for analysis.
The force required to remove an average discharged spirocyst or nematocyst from tentacles is the "intrinsic adherence.
Four parameters were measured to analyze nematocyst-mediated adhesive force: total adhesive force; number of discharged nematocysts; number of discharged spirocysts; and adhesive force in tentacles in which nematocyst and spirocyst discharge had been inhibited by pretreatment with formaldehyde to measure tentacle stickiness.
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).
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.
s] is the intrinsic adherence of spirocysts, expressed as mgf/spirocyst;