Table 2. Discriminant function of morphometric ratios and correct classification of males and females of each Scylla spp.

Measured morphometric characteristics include carapace width (CW), CW at spine 8 (8CW), internal carapace width (ICW), carapace length (CL), abdomen width (AW), right cheliped’s dactyl length (DL), right chelipeds propodus depth (PD), right cheliped’s propodus width (PW), right cheliped’s propodus length (PL) and right cheliped’s merus length (ML).

Discriminant function	Correct classification, cross-validation (%)
Scylla olivacea	100, 100
$0.048\frac{8\mathrm{CW}}{\mathrm{CW}}-0.071\frac{\mathrm{ICW}}{\mathrm{CW}}-0.404\frac{\mathrm{CL}}{\mathrm{CW}}-1.006\frac{\mathrm{AW}}{\mathrm{CW}}+0.164\frac{\mathrm{DL}}{\mathrm{CW}}+0.472\frac{\mathrm{PD}}{\mathrm{CW}}+0.224\frac{\mathrm{PL}}{\mathrm{CW}}+0.259\frac{\mathrm{ML}}{\mathrm{CW}}+0.334\frac{\mathrm{PW}}{\mathrm{CW}}$
Cut-off value = 0 (>0 = male; <0 = female)
S. tranquebarica	100, 100
$0.079\frac{\mathrm{ICW}}{\mathrm{CW}}-0.152\frac{8\mathrm{CW}}{\mathrm{CW}}+0.092\frac{\mathrm{CL}}{\mathrm{CW}}+0.926\frac{\mathrm{AW}}{\mathrm{CW}}-0.068\frac{\mathrm{DL}}{\mathrm{CW}}-0.234\frac{\mathrm{PD}}{\mathrm{CW}}-0.249\frac{\mathrm{PL}}{\mathrm{CW}}-0.254\frac{\mathrm{PW}}{\mathrm{CW}}$
Cut-off value = 0 (>0 = female; <0 = male)
S. paramamosain	100, 100
$0.046\frac{\mathrm{ICW}}{\mathrm{CW}}-0.074\frac{\mathrm{CL}}{\mathrm{CW}}-0.948\frac{\mathrm{AW}}{\mathrm{CW}}+0.099\frac{\mathrm{DL}}{\mathrm{CW}}+0.496\frac{\mathrm{PD}}{\mathrm{CW}}+0.241\frac{\mathrm{PL}}{\mathrm{CW}}+0.05\frac{\mathrm{ML}}{\mathrm{CW}}+0.41\frac{\mathrm{PW}}{\mathrm{CW}}$
Cut-off value = 0 (>0 = male; <0 = female)