. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SEA URCHIN FERTILIZATION SUCCESS 263 Table I Effect of distance, up unit down stream position, ami current velocity on the percentage (arcsine transformed) of eggs being fertilized SV DF SS MS Distance 2 Position 1 Current 1 *** Interaction 2 NS Error 53 NS Total 59 *** = P < .001, NS = not significant. Eggs were held in Nitex bags. Analysis of covariance with two main effects; distance between urchin and bags, and up-current or down-c
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SEA URCHIN FERTILIZATION SUCCESS 263 Table I Effect of distance, up unit down stream position, ami current velocity on the percentage (arcsine transformed) of eggs being fertilized SV DF SS MS Distance 2 Position 1 Current 1 *** Interaction 2 NS Error 53 NS Total 59 *** = P < .001, NS = not significant. Eggs were held in Nitex bags. Analysis of covariance with two main effects; distance between urchin and bags, and up-current or down-current position. The current velocity was the covariate. urchin did not spawn or if it was female, it was replaced. All urchins, within an arena, were induced to spawn within 1 min. Control arenas with no males were used to check for ambient sperm in the water. Spawning lasted approx- imately 5 min. After 20 min, the egg bags were collected and rinsed in seawater. Within 2 h, 250 eggs per bag were assayed for the presence of a fertilization membrane. The 4 Nitex bags per arena were pooled to give 1000 eggs per replicate. There were 8 to 12 replicates for each level of male size and density. One set of replicates (3 male sizes X 3 male densities) was attempted each day. Arenas, in the above experiment, were 1 m2 at low density and nr for medium and high density treat- ments ( 1 urchin per arena at low density, 1 and 4 urchins per arena at medium and high density). This was done because it was impossible to place 'A of an urchin in the small arena and impractical to place (and spawn within the experimental time frame) 16 males in a large arena. Although both methods (varying urchin number and area) are true density manipulations, this design con- founds the effect of number and distance between males and eggs at the low and medium densities. In another study (Levitan et ai, 1991), the relative influence of vary- ing urchin number and distance was examined. The results s
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
