First evidence for postzygotic reproductive isolation between two populations of Eurasian perch (Perca fluviatilis L.) within Lake Constance

Table 1 Various fitness parameters for parental and hybrid crosses

Crosses	Number of females	Number of eggs	Fertilized	Hatched	CFM
East. pop.	5	788 (139)	0.953 (0.002)	0.651 (0.108)	0.625 (0.104)
West. pop.	6	773 (56)	0.985 (0.009)	0.835 (0.049)	0.824 (0.054)
F ₁ 1	7	1030 (61)	0.986 (0.005)	0.517 (0.087)	0.510 (0.086)
F ₁ 2	9	917 (71)	0.560 (0.149)	0.507 (0.116)	0.344 (0.098)

Mean (± SE) proportions of fertilized eggs, hatched larvae (from fertilized eggs) and CFM (combined fitness measure, for details see text) of the different crosses. East. pop./West. pop. = crosses within populations. Hybrid crosses F₁1 = female eastern population/male western population, F₁2 = female western population/male eastern population.

ISSN: 1742-9994