Growth in these experiments was estimated by counting the number of autozooids and bifurcations in a colony.
After 14 days, the plates were returned to the laboratory and the number of autozooids and bifurcations counted for each colony.
Each apparatus was removed daily and the numbers of autozooids, bifurcations, and brood chambers were counted for each colony.
Larval swimming duration and colony orientation significantly affected growth as measured by the number of autozooids and bifurcations in a colony ([ILLUSTRATION FOR FIGURE 3A, B OMITTED]; Table I).
The only significant interaction between main factors was between colony orientation and proximity of a conspecific (F = 7.6, P = 0.006 for brood chambers; F = 6.5, P = 0.01 for autozooids).
On average, 24-h colonies had half as many autozooids, bifurcations, and brood chambers as did 1-h colonies over the same time of development.
Five sea pansies were anesthetized, their autozooid polyps were excised, and the polyp tissues were digested in the papain solution as described above.
Sea pansy colonies were anesthetized as described above and autozooid polyps, as well as rat heart tissues, were finely minced.
Small pieces of colonial tissue (rachis) bearing one autozooid polyp and several siphonozooid polyps (also containing photocytes) were excised from unanesthetized colonies and placed individually in assay vials containing 150 [[micro]liter] of ASW.
Autozooid polyps were excised from anesthesized colonies as above, and immersed in freshly prepared Zamboni's fixative (4% paraformaldehyde and 7.5% saturated picric acid in phosphate buffer with 2.4% NaCl, pH 7.4) for 24 h at 4 [degrees] C.
In both autozooid and siphonozooid polyps, photocytes are clustered in specific locations of the endodermal layer where cells filled with highly refringent granules (presumably acting as diffuse reflectors for the light emission) predominate (Anctil et al., 1984; Awad and Anctil, 1994).
Specific Cx43-like immunoreactivity was present in all tissue layers of autozooid polyps but was more prevalent in the luminescent endoderm and in the mesogleal nerve net.