. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 246 L. FRANCIS CO CL en o. Volume (Log Scale) Figure 3. Change in the ratio of external perimeter to upper surface area (P/S) with increasing volume. A. The upper line [P,/S, = V,~° ] shows the decline in P/S with increasing volume for a cylinder that "grows" isometrically, as aclonal anemones do. The following ba- sic, geometric relationships were used in the calculations: L = height = diameter; S, = upper surface area = ir/4 • L: = L2; P, = perimeter = 7T L; P,/S, = 4/L; V, = volume = tt/4-
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 246 L. FRANCIS CO CL en o. Volume (Log Scale) Figure 3. Change in the ratio of external perimeter to upper surface area (P/S) with increasing volume. A. The upper line [P,/S, = V,~° ] shows the decline in P/S with increasing volume for a cylinder that "grows" isometrically, as aclonal anemones do. The following ba- sic, geometric relationships were used in the calculations: L = height = diameter; S, = upper surface area = ir/4 • L: = L2; P, = perimeter = 7T L; P,/S, = 4/L; V, = volume = tt/4-L3. B. The lower line [Pc/Sc = Vc"°5] shows the decline in P/S for "growth" of a compact, sheet-like clone, modeled as a cylinder that increases in diameter, but not in height. Geometric relationships are as follows: L = height = ; Sc = upper surface area = n • S, = ?r/4 n • L2; Pc = perimeter = it L • n°5; Pc/Sc = 4 L-'-n-05; Vc = volume = V,-n = jt/4 L3n. Discussion Among anemones of the rocky intertidal, the clonal mode of growth is strongly correlated with other impor- tant characters including body size, habitat, and aggres- siveness. Clonal species tend to be aggressive and to live on the upper shore, while aclonal forms tend to be non- aggressive and to live low on the shore. Twenty-three of the 35 species sampled belong to one or the other of these categories (Fig. 1). None are simultaneously clonal, non- aggressive and inhabitants of the lower shore. None are aclonal, aggressive inhabitants of the upper shore. This is a very striking pattern that demands explanation. There are many different methods of asexual replica- tion among the anemones including budding, longitudi- nal fission, bilateral fission, various kinds of unequal fragmentation (Chia, 1976), and internal brooding of ge- netically identical young (Black and Johnson, 1979). This suggests that cloning has arisen repeatedly within this group. Further, since clonal and aclona
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
