Research Article

Postzygotic Isolation Evolves before Prezygotic Isolation between Fresh and Saltwater Populations of the Rainwater Killifish, Lucania parva

Table 3

Analyses of L. parva survival in the presence or absence of methylene blue (MB) for hard water (KH8) and salt water (20 ppt). Results of generalized linear model for (a) proportion of eggs hatched, (b) proportion of fry that survived to 14 days after hatch, (c) total survival (proportion of eggs that survived to 14 days after hatch). Statistically significant values are indicated in bold. Number of families per water treatment: without MB KH8 = 25, 20 ppt = 25, with MB KH8 = 32, 20 ppt = 32; total = 114. Number of eggs per water treatment: without MB KH8 = 224, 20 ppt = 326, with MB KH8 = 1255, 20 ppt = 1019. Number of fry per water treatment: without MB KH8 = 44, 20 ppt = 242, with MB KH8 = 1129, 20 ppt = 908.
(a) Proportion of eggs hatched

Sourcedf χ 2 P

MB151.91<0.0001
Water Chemistry135.45<0.0001
MB * Water Chemistry 129.80<0.0001
Cross24.270.014
MB * Cross 25.390.0045
Water Chemistry * Cross22.020.1325
MB * Water Chemistry * Cross20.130.8821

(b) Proportion of fry survive

Sourcedf χ 2 P

MB100.9574
Water Chemistry11.410.2357
MB * Water Chemistry10.120.7278
Cross20.960.3828
MB * Cross20.070.9285
Water Chemistry * Cross 27.060.0009
MB * Water Chemistry * Cross 24.580.0103

(c) Total survival

Sourcedf χ 2 P

MB156.55<0.0001
Water Chemistry122.27<0.0001
MB * Water Chemistry 112.040.0005
Cross22.740.0644
MB * Cross22.850.0578
Water Chemistry * Cross 24.310.0135
MB * Water Chemistry * Cross22.670.0692