84
3. MEASURING GROWTH AND FORM
Fig.3.15. Haliclona oculata . Plots of the
morphological measurements da, db,
b_angle,g_angle, rb, andDj,oxagainstthe
corresponding erosion values. Meanvalues are indicatedwith an asterisk and the
standard deviation with a dashed line.
Values ofthe regressioncoefficient rcare
listed in Table 3.2.
1.20
1.00
~ 0.80
~ 0.60
0·40
0.20
*
0 .05
0.10
0.15
0.20
0 .25
eros ion value (gil-I)
1.40
1.20
1.00
~ 0.80
~ 0.60
0 .20
0.05
0 .10
0.15
0 .20
0.25
erosion value (gil-I)
3·00
3·00
2.5 0
2·50
~
~
E.
2.00
"
2.00
..=.
"
' " *
~
e:.,
' "
*
~ 1·50
§ 1·50
x
' =
;ok
x
X
x
I
x
I
""
CG
x
1.00
~::
1.00
~:
"
;:,
x
x
0·50
*
0 ·50
0.05
0.10
0.15
0.20
0.25
erosion value (gil-I )
0 .05
0.10
0. 15
0 . 20
0.25
erosion value (gil-I)
3·50
2.00
3·00
1.80
2·50
'2 2.00
1.60
.s
~:
x
]
-e 1·50
0
x
*
1·40
~
x
x ,. .
x
""
,.. ~ ... ~
1.00
,.,
Of
;~:
1.20
0·50
0.05
0.10
0.15
0.20
0 .25
erosion value (gil-I)
0.05
0.10
0.15
0.20
0.25
erosion value (gil-I)
3.3.3 A Comparison of the Morphological Measurements
in a Range of Growth Forms of the Three Species
Table 3.2 shows that all three species exhibited a similar trend in the measurements pertaining to the thickness of branches (da and db). The growth forms
gradually transformed from a thin-branching shape to a compact shape along
a gradient of increasing exposure to water movement. In Figs. 3-13 and 3-14 it
can be seen that the variance of da and db increased with exposure to water
movement. A possible explanation is that with the increase in exposure to
water movement the probability also increases th at the growth form may be
damaged, adding to the variance. The results in Table 3.2 also demonstrate,