272 
Fishery Bulletin 111(3) 
Table 3 
Regression equations, sample sizes, coefficients of multiple determination ( R 2 ), standard errors, 
and P-values for penis length, whole wet weight (Wt), lip width (LW), and shell width (SW) as 
functions of shell length (SL), LW, or SW from our study of channeled whelk ( Busycotypus cana- 
liculatus) collected in August 2010 and July 2011 in Buzzards Bay, Massachusetts. Standard error 
(SE) is ±1 SE. 
Regression 
Equation 
Sample 
size ( n ) 
R 2 
Standard 
error 
P-value 
Penis length 
-249.171 + 128.982 * logic SL 
92 
0.801 
4.048 
<2.2e-16 
Female logioWt 
-4.437 + 3.139 * logio SL 
115 
0.978 
0.049 
<2.2e-16 
Male logioWt 
-4.204 + 3.027 * log 10 SL 
112 
0.956 
0.053 
<2.2e-16 
LogioWt 
-4.385 + 3.114 * logio SL 
227 
0.979 
0.051 
<2.2e-16 
Female LW 
3.699 + 0.504 * SL 
115 
0.976 
2.779 
<2.2e-16 
Male LW 
6.453 + 0.473 * SL 
112 
0.958 
2.177 
<2.2e-16 
SW 
-9.607 + 1.233 * LW 
166 
0.938 
2.933 
<2.2e-16 
LW 
11.954 + 0.761 * SW 
166 
0.938 
2.304 
<2.2e-16 
mm SL (Fig. 5A) and 9 years of age (Fig. 5C). No LD 
or R females exceeded 190 mm SL (Fig. 5A), although 
there were females assigned as LD at the age of 
12 years and females identified as stage R at the age of 
14 years (Fig. 50. The largest males classified as stage 
I were 120 mm SL; males identified as ED did not 
exceed 130 mm SL, and LD males did not exceed 
140 mm SL (Fig. 5B). Similar to females in stages I 
and ED, males in stages I and ED did not exceed the 
ages of 8 years and 9 years, respectively; however, the 
ages of LD males also were not older than 9 years (Fig. 
5D). Females were assigned to stage M as small as 
159 mm SL and at 8 years of age, and males were 
classified in stage M as small as 104 mm SL and at 6 
years of age (Fig. 5). Both males and females included 
relatively few LD individuals, indicating that spawn- 
ing had not yet occurred and development was not yet 
complete. 
Table 4 
Covariance analysis on regressions of channeled whelk ( Busycotypus canaliculatus) growth in 
weight (Wt), lip width (LW), and square-root (Sqrt) shell length (SL) from our study of this 
species collected in August 2010 and July 2011 in Buzzards Bay, Massachusetts. Sample size 
for each regression was 112 male and 115 female channeled whelk. The female intercept and 
slope are as stated. The actual male intercept is calculated by adding the male intercept esti- 
mate to the female intercept estimate. The actual male slope is calculated by adding the male 
slope estimate to the female slope estimate. Standard error (SE) is ±1 SE. 
Standard 
Regression 
Coefficient 
Estimate 
error 
P-value 
LogioWt ~ logio SL * sex 
Female intercept 
-4.437 
0.103 
<2e-16 
Female slope 
3.139 
0.046 
<2e-16 
Male intercept 
0.233 
0.162 
0.151 
Male slope 
-0.112 
0.075 
0.138 
LogioWt - logi 0 SL 
Intercept 
-4.385 
0.066 
<2e-16 
Slope 
3.114 
0.030 
<2e-16 
LW ~ SL * sex 
Female intercept 
3.699 
1.168 
0.002 
Female slope 
0.504 
0.007 
<2e-16 
Male intercept 
2.754 
1.814 
0.130 
Male slope 
-0.031 
0.013 
0.015 
Sqrt (SL growth ) - sqrt (age) * sex 
Female intercept 
7.919 
0.052 
<2e-16 
Female slope 
-1.496 
0.018 
<2e-16 
Male intercept 
-0.039 
0.073 
0.594 
Male slope 
-0.209 
0.026 
4.63e-08 
