Morphological asymmetry is widely used to measure developmental instability and higher levels of asymmetry often correlate with decreased mating success, increased inbreeding, increased stress, and decreased habitat quality. We studied asymmetry and relationships between asymmetry and host identity in two flea species, host generalist Xenopsylla ramesis and host specialist Parapulex chephrenis and asked 1) what are levels of asymmetry in their femurs and tibiae, 2) which type of asymmetry predominates and 3) whether fleas that fed on host species distantly related to their principal host species produce offspring that exhibit greater asymmetry than those that had fed on their principal host species. We found fluctuating asymmetry in femurs and tibiae of X. ramesis and in the tibiae of P. chephrenis as well as significantly left-handed directional asymmetry in the femurs of P. chephrenis. Host species identity significantly impacted asymmetry in leg segments of P. chephrenis but not in those of X. ramesis. Offspring asymmetry increased when mother fleas fed on a host most distantly related to the principal host. Fleas parasitizing multiple host species might compensate for developmental instability when utilizing a novel host species; therefore, host-switching events in host specific parasites could be constrained by the relatedness between a novel and a principal host species.
- Received August 15, 2016.
- Accepted January 24, 2017.
- © 2017. Published by The Company of Biologists Ltd