Subterranean organisms presumably share morphological, physiological, and behavioral adaptations to subterranean life. Morphological characteristic, so called troglomorphoses, presumably evolved paralelly or convergently. We studied morphological differences between cave and surface populations of the amphipod crustacean Synurella ambulans. We selected four, geographically neighbouring pairs of surface and cave populations. We measured eye perimeter and surface, lengths of antenna I and II, lengths of pereopods V-VII, length and width of propodus VI and length and length of dactylus VI. Population pairs differ from each other in three to nine traits, however, we found little evidence for parallel evolution. As compared to respective surface populations, all cave populations have smaller eye area. Additionally, three cave populations have shorter antenna II than their surface counterparts. Other traits evolved non-predictably and cannot be attributed to ecological differences between surface and cave environment.
|