Shape based assignment tests suggest transgressive phenotypes in natural sculpin hybrids (Teleostei, Scorpaeniformes, Cottidae)

Table 1 Assignment success under alternative CVA models

Assigned Group	Broel	Naaf	Invasive	BI Hybrids	CVA model
Broel	90.6	1.3	2.5	25.8	Based on parental populations
Naaf	4.3	93.4	0.0	11.3
Invasive	0.9	0.0	92.5	25.8
n.s.	4.3	5.3	5.0	37.1
Broel	87.2	5.3	0.0	1.6	Including parental groups and hybrids
Naaf	2.6	89.5	0.0	1.6
Invasive	0.9	0.0	85.4	6.5
BI hybrid	6.8	1.3	12.2	83.9
n.s.	2.6	3.9	0.0	6.5

Assignment of sculpins to their population of origin based on body shape. A model based only on the differentiation of parental populations is very effective in identifying pure sculpins but assigns the majority of hybrids to pure populations as false positives. A more complex model that includes the shape components specific to hybrids correctly identifies the majority of all hybrids. The overall success of parental group assignment is decreased when hybrids are taken into account as they overlap with parental phenotypic values.