Phenotypic integration indices in the four different isopod populations (two populations from different ecotypes in two different lakes).

NOTE. – The average connectivity per trait is significantly higher in the novel stonewort ecotypes than in the source reed ecotypes (F1,24 = 10.14; P = 0.004). In contrast, the index of modularity (ranging from 0 (total absence of modular structure) to 0.5 (full modular structure)) is higher in the source reed ecotype in both lakes compared to the novel stonewort ecotype.