Table 4 Estimates of genetic (\({\text{r}}_{\text{A}}\)), environmental (\({\text{r}}_{\text{E}}\)) and phenotypic (\({\text{r}}_{\text{P}}\)) correlations between shell color and cuticle deposition traits at 640 nm, and the corresponding regression coefficients (\({\text{b}}_{\text{A}}\), \({\text{b}}_{\text{E}}\), \({\text{b}}_{\text{P}}\))

Egg color

Brown

White

Tinted

Brown

Age (weeks)

31

50

32

39

62

Pre-stain Abs@640 nm and Post-stain Abs@640 nm

\({\text{r}}_{\text{A}}\)

0.50 (0.12)

0.58 (0.09)

0.48 (0.18)

0.57 (0.09)

0.58 (0.11)

0.55 (0.05)

\({\text{r}}_{\text{E}}\)

0.71 (0.03)

0.59 (0.06)

0.28 (0.06)

0.33 (0.07)

0.49 (0.05)

0.48*(0.09)

\({\text{r}}_{\text{P}}\)

0.64 (0.02)

0.58 (0.02)

0.33 (0.03)

0.44 (0.03)

0.51 (0.02)

0.50*(0.05)

\({\text{b}}_{\text{A}}\)

1.04 (0.29)

1.22 (0.23)

6.07 (2.59)

1.92 (0.37)

0.68 (0.15)

1.21*(0.27)

\({\text{b}}_{\text{E}}\)

1.41 (0.10)

1.57 (0.21)

2.61 (0.62)

1.56 (0.35)

0.94 (0.12)

1.42*(0.18)

\({\text{b}}_{\text{P}}\)

1.30 (0.05)

1.37 (0.07)

3.38 (0.35)

1.77 (0.12)

0.81 (0.04)

1.58*(0.20)

Pre-stain Abs@640 nm and ΔAbs@640 nm

\({\text{r}}_{\text{A}}\)

0.02 (0.16)

0.13 (0.13)

0.42 (0.19)

0.31 (0.12)

− 0.32 (0.14)

0.11*(0.13)

\({\text{r}}_{\text{E}}\)

0.28 (0.06)

0.26 (0.09)

0.18 (0.07)

0.12 (0.08)

− 0.04 (0.07)

0.16*(0.06)

\({\text{r}}_{\text{P}}\)

0.19 (0.03)

0.19 (0.04)

0.24 (0.03)

0.21 (0.03)

− 0.14 (0.03)

0.14*(0.07)

Post-stain Abs@640 nm and ΔAbs@640 nm

\({\text{r}}_{\text{A}}\)

0.88 (0.04)

0.88 (0.03)

0.99 (0.01)

0.96 (0.01)

0.58 (0.11)

0.92*(0.03)

\({\text{r}}_{\text{E}}\)

0.88 (0.02)

0.93 (0.01)

0.99 (0.01)

0.97 (0.01)

0.85 (0.02)

0.93*(0.02)

\({\text{r}}_{\text{P}}\)

0.87 (0.01)

0.91 (0.01)

0.99 (0.01)

0.97 (0.01)

0.78 (0.01)

0.90*(0.04)