Performance landscape showing variation in morphology and swimming performance between parentals (<i>X. malinche</i> and <i>X. birchmanni</i>) and between hybrids that exhausted and hybrids that did not.

<p>Red represents longer endurance time. Means and standard errors of residual PC 1 and residual PC 2 for hybrids (A and C) and parentals (B and D) are shown. Morphometric visualizations were magnified by a factor of 3 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0109025#pone.0109025-Langerhans5" target="_blank">[83]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0109025#pone.0109025-Haas1" target="_blank">[85]</a>.